Faculty Profiles - NAKAMURA Kazutoshi

Papers - NAKAMURA Kazutoshi

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Low plasma 25-hydroxyvitamin D levels are not associated with a high risk of recurrent falls in community-dwelling Japanese adults: the Murakami cohort study

Toshi Nishikura, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Toshiko Saito, Akemi Takahashi, Ribeka Takachi, Ryosaku Kobayashi, Rieko Oshiki, Shoichiro Tsugane, Kei Watanabe, Kazutoshi Nakamura

Archives of Osteoporosis 19 ( 1 ) 2024.4

Chronic Pain in the Lower Extremities and Low Back is Associated With Recurrent Falls in Community-Dwelling Japanese People Aged 40-74 Years. International journal

Yuko Nagashima, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Akemi Takahashi, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Ribeka Takachi, Shoichiro Tsugane, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

Archives of physical medicine and rehabilitation 105 ( 3 ) 498 - 505 2024.3

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: To determine the longitudinal association between chronic pain in the lower extremities and low back and the odds of recurrent falls in middle-aged and older people. DESIGN: A cohort study. SETTING: Communities in Japan. PARTICIPANTS: Participants were 7540 community-dwelling volunteers aged 40-74 years (N=7540). The baseline survey was a self-administered questionnaire conducted between 2011-2013. Predictors were presence of chronic pain in the knee, foot or ankle, and low back, with the degree of pain categorized as none, very mild/mild, moderate, or severe/very severe. Covariates in the multivariate model of chronic pain in a site were demographics, body mass index, physical activity level, disease history, and chronic pain in the other 2 sites. Logistic regression analysis was used to calculate odds ratios (ORs). INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Recurrent falls in the year before the 5-year follow-up survey. RESULTS: Mean participant age was 60.2 years. Higher degrees of chronic pain were associated with higher odds of recurrent falls for the knee (P=.0002) with a higher OR of 1.48 (95% CI: 1.11-1.97), for the foot or ankle (P=.0001) with a higher OR of 1.97 (95% CI: 1.36-2.86), and for the low back (P=.0470) with a higher OR of 1.45 (95% CI: 1.09-1.91) in those with any degree of pain relative to those without pain. Higher degrees of chronic knee pain were associated with higher odds of recurrent falls in women (P=.0005), but not in men (P=.0813). Meanwhile, higher degrees of chronic low back pain were associated with the odds of recurrent falls in men (P=.0065), but not in women (P=.8735). CONCLUSIONS: Chronic pain in the knee, foot or ankle, and lower back was independently and dose-dependently associated with a higher risk of recurrent falls. A marked sex-dependent difference was also noted in the association.

DOI： 10.1016/j.apmr.2023.09.021

Urinary Biomarkers in Screening for the Usual Intake of Fruit and Vegetables, and Sodium, Potassium, and the Sodium-to-Potassium Ratio: Required Number and Accuracy of Measurements

Aoi Suzuki, Ribeka Takachi, Junko Ishihara, Sachiko Maruya, Yuri Ishii, Kumiko Kito, Kazutoshi Nakamura, Junta Tanaka, Taiki Yamaji, Hiroyasu Iso, Motoki Iwasaki, Shoichiro Tsugane, Norie Sawada

Nutrients 2024.2

Validity of the intake of sugars, amino acids, and fatty acids estimated using a self-administered food frequency questionnaire in middle-aged and elderly Japanese: the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT) Protocol Area.

Utako Murai, Junko Ishihara, Ribeka Takachi, Ayaka Kotemori, Yuri Ishii, Kazutoshi Nakamura, Junta Tanaka, Hiroyasu Iso, Shoichiro Tsugane, Norie Sawada

Journal of epidemiology 2024.1

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The Japanese database of food composition was revised in 2020, during which both the number of food items and the number of food items measured for sugars, amino acids, and fatty acids were increased. We evaluated the validity of estimated intakes of sugars, amino acids and fatty acids using a long-food frequency questionnaire (FFQ) among middle-aged and elderly Japanese. METHODS: From 2012 to 2013, 240 men and women aged 40-74 years from five areas in the JPHC-NEXT protocol were asked to respond to the long-FFQ and provide a 12-day weighed food record (WFR) as reference. The long-FFQ, which included 172 food and beverage items and 11 seasonings, was compared with a 3-day WFR, completed during each distinct season, and validity was assessed using Spearman's correlation coefficients. RESULTS: Percentage differences based on the long-FFQ with the 12-day WFR in men and women varied from -83.9% to 419.6%, and from -75.8% to 623.1% for sugars, -17.5% to 2.8% and -5.8% to 19.6% for amino acids, and -58.5% to 78.8% and -43.4% to 129.3% for fatty acids, respectively. Median values of correlation coefficients for the long-FFQ in men and women were 0.52 and 0.42 for sugars, 0.38 and 0.37 for amino acids, and 0.42 and 0.42 for fatty acids, respectively. CONCLUSIONS: The long-FFQ provided reasonable validity in estimating the intakes of sugars, amino acids, and fatty acids in middle-aged and elderly Japanese. Although caution is warranted for some nutrients, these results may be used in future epidemiological studies.

DOI： 10.2188/jea.JE20230132

Body mass index, height, and osteoporotic fracture risk in community-dwelling Japanese people aged 40–74 years

Toshi Nishikura, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Akemi Takahashi, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Ribeka Takachi, Shoichiro Tsugane, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

Journal of Bone and Mineral Metabolism 2023.12

Reproducibility and dietary correlates of plasma polyphenols in the JPHC-NEXT Protocol Area study. International journal

Nagisa Mori, Neil Murphy, Norie Sawada, David Achaintre, Taiki Yamaji, Augustin Scalbert, Junko Ishihara, Ribeka Takachi, Kazutoshi Nakamura, Junta Tanaka, Motoki Iwasaki, Hiroyasu Iso, Manami Inoue, Marc J Gunter, Shoichiro Tsugane

European journal of clinical nutrition 2023.10

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: In recent years, an increasing number of epidemiological studies have suggested a role of polyphenols in the prevention of chronic diseases. Prospective cohort studies have typically measured polyphenol concentrations in a single blood sample and the reproducibility of plasma polyphenol measurements is largely unknown. OBJECTIVE: We evaluated the reproducibility of 35 plasma polyphenols collected at an interval of 1-year. We also examined correlations of these polyphenols with food group intakes calculated from weighed food records (WFR) and food frequency questionnaire (FFQ). METHODS: The study included 227 middle-aged participants from the JPHC-NEXT Protocol Area in Japan. We measured 35 polyphenols in plasma collected at two points 1-year apart. Food group intakes were calculated from 12-day WFR and FFQ. For the reproducibility analysis, the intraclass correlation coefficient (ICC) of 35 polyphenol concentrations were examined between the two points. Pearson's partial correlations was used to assess the correlation between polyphenols and food groups. RESULTS: Moderate- to high ICCs were observed for tea-originated polyphenols such as gallic acid, quercetin, epigallocatechin, and kaempferol - and coffee-derived polyphenols, such as caffeic acid, and ferulic acid. For the dietary analyses, moderate correlations were observed for non-alcoholic beverages intake and epigallocatechin, epicatechin, catechin, and gallic acid. For green tea, higher correlations were observed with these polyphenols. CONCLUSION: Plasma concentrations of tea and coffee-related polyphenols, except for catechin, had good reproducibility over a 1-year period. The correlations between intake of non-alcoholic beverages, particularly green tea, and tea polyphenols, indicated moderate- to high correlations.

DOI： 10.1038/s41430-023-01349-w

Alcohol consumption, smoking, and risk of dementia in community-dwelling Japanese people aged 40-74 years: The Murakami cohort study. International journal

Shugo Kawakami, Ren Yamato, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Akemi Takahashi, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Ribeka Takachi, Shoichiro Tsugane, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

Maturitas 176 107788 - 107788 2023.10

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: Alcohol drinking and tobacco smoking have impacts on lifestyle-related diseases, but their association with dementia remains a debated topic. This study aimed to examine longitudinal associations between alcohol consumption, smoking, and dementia risk in middle-aged and older Japanese people. METHODS: This study used a cohort design with an 8-year follow-up. Participants were community-dwelling Japanese people (N = 13,802) aged 40-74 years. The baseline survey, including a self-administered questionnaire, was conducted in 2011-2013. Predictors were alcohol consumption and tobacco smoking. The outcome was incident dementia obtained from a long-term care insurance database. Covariates were demographics, lifestyle factors, body mass index, general health status, and history of stroke, diabetes, and depression. RESULTS: Participant mean age was 59.0 years. The 1-149, 150-299, and 300-449 g ethanol/week groups had significantly lower adjusted hazard ratios (HRs) (0.62, 0.59, and 0.47, respectively) compared with the reference group, with no significant linear association. HRs increased toward 1 when past-drinkers and those with poor health status and a disease history were excluded (0.80, 0.66, and 0.82, respectively). Higher smoking levels were dose-dependently associated with a higher HR (adjusted P for trend = 0.0105), with the ≥20 cigarettes/day group having a significantly higher adjusted HR (1.80). Heavy drinkers (≥449 g ethanol/week) with smoking habits, but not those without smoking habits, had higher dementia risk (P for interaction = 0.0046). CONCLUSION: Light-to-moderate alcohol consumption is associated with decreased dementia risk, and smoking is dose-dependently associated with increased dementia risk, with an interaction between high alcohol consumption and smoking on dementia risk.

DOI： 10.1016/j.maturitas.2023.107788

縦断デザインを用いた,プロテオミクスによる認知症尿バイオマーカーの探索

渡邊裕美, 平尾嘉利, 春日健作, 北村香織, 中村和利, 山本格

Dementia Japan 37 ( 4 ) 680 - 680 2023.10

Chronic kidney disease awareness and its determinants in middle-aged and older Japanese adults: Observations from a 5-year follow-up of the Uonuma cohort study. International journal

Keiko Kabasawa, Yumi Ito, Noriaki Iino, Kazutoshi Nakamura, Norie Sawada, Shoichiro Tsugane, Junta Tanaka, Ichiei Narita

Nephrology (Carlton, Vic.) 28 ( 10 ) 567 - 575 2023.10

Language：English Publishing type：Research paper (scientific journal)

AIM: Despite global efforts in public health campaigns concerning chronic kidney disease (CKD), awareness of the condition remains low. We evaluated CKD awareness and related factors to identify an effective way to raise awareness. METHODS: This study assessed laboratory-confirmed CKD and self-reported CKD using a population-based cohort (baseline from 2012 to 2014, age ≥40 years) in Niigata, Japan. Self-reported CKD was obtained at a 5-year follow-up survey and laboratory-confirmed CKD was diagnosed when an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or dipstick urinary protein ≥1+ was observed in at least two health check-ups during the 5-year period. CKD awareness was defined as a match between laboratory-confirmed and self-reported CKD. The association between characteristics and CKD awareness was tested by multivariable logistic regression analysis with adjustment for eGFR and other potential confounders. RESULTS: The analytic population comprised 7472 individuals (mean age, 65.6 years old, 51.2% women) and 19.4% with laboratory-confirmed CKD. The sensitivity and specificity of the survey question concerning self-reported CKD were 12.4% and 98.2%, respectively. Among the participants with laboratory-confirmed CKD, significant factors associated with CKD awareness were male sex (adjusted odds ratio [95% confidence interval], 1.81 [1.27, 2.59]), a history of urinary tract stone (1.86 [1.06, 3.26]), age (0.97 [0.95, 0.99]), and married status (0.66 [0.44, 0.99]). CONCLUSION: Our findings suggest that known lifestyle-related diseases that could cause CKD are not associated with CKD awareness independently of kidney function and that a sex-dependent approach may help to raise CKD awareness in community-dwelling Japanese adults.

DOI： 10.1111/nep.14170

Vegetable and Fruit Intake Frequency and Mortality in Patients With and Without Chronic Kidney Disease: A Hospital-Based Cohort Study. International journal

Minako Wakasugi, Akio Yokoseki, Masakazu Wada, Takeshi Momotsu, Kenji Sato, Hiroyuki Kawashima, Kazutoshi Nakamura, Osamu Onodera, Ichiei Narita

Journal of renal nutrition : the official journal of the Council on Renal Nutrition of the National Kidney Foundation 33 ( 4 ) 566 - 574 2023.7

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: Patients with advanced chronic kidney disease (CKD) are generally discouraged from consuming high amounts of vegetables and fruits given the potential risk of hyperkalemia. In the general population, however, lower vegetable and fruit intake is associated with higher mortality. This Japanese hospital-based prospective cohort study including non-CKD and CKD participants examined whether the frequency of vegetable and fruit intake is associated with mortality, and whether the presence of CKD modifies this association. METHODS: Participants were 2,006 patients who visited the outpatient department of a general hospital between June 2008 and December 2016 (55% men; mean age, 69 years). Among these participants, 902 (45%) and 131 (7%) were non-dialysis-dependent patients with CKD and hemodialysis patients, respectively. The frequency of vegetable and fruit intake was determined by a self-report questionnaire using an ordinal scale, "never or rarely," "sometimes," and "every day." Multivariable Cox proportional hazards analysis was conducted, adjusting for potential confounders. RESULTS: Vegetable and fruit intake frequency decreased with worsening CKD stage (P for trend < .001). Baseline serum potassium levels stratified by CKD stage were similar across the three vegetable and fruit intake frequency groups. During a median follow-up of 5.7 years, 561 participants died (47.1/1,000 person-years). Adjusted hazard ratios relative to the "every day" group were 1.25 (95% confidence interval, 1.04-1.52) and 1.60 (95% confidence interval, 1.23-2.08) for the "sometimes" and "never or rarely" groups, respectively, after adjusting for demographic factors, comorbidities, and CKD status. When stratified by CKD status, a similar, albeit non-significant, dose-dependent relationship was observed between vegetable and fruit intake frequency and all-cause mortality irrespective of CKD status, with no effect modification by CKD status (Pinteraction = .69). CONCLUSION: A lower frequency of vegetable and fruit intake is significantly associated with a higher risk of death regardless of CKD status.

DOI： 10.1053/j.jrn.2023.01.011

Sex Differences in the Association Between Body Mass Index and Dementia Risk in Community-Dwelling Japanese People Aged 40-74 Years. International journal

Alena Zakharova, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Akemi Takahashi, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Ribeka Takachi, Shoichiro Tsugane, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

Journal of Alzheimer's disease : JAD 94 ( 3 ) 949 - 959 2023.6

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The association between body mass index (BMI) and dementia risk is heterogeneous across age groups and might be influenced by sex. OBJECTIVE: This study aimed to clarify sex differences in the association between BMI and dementia risk in community-dwelling people. METHODS: This cohort study with an 8-year follow-up targeted 13,802 participants aged 40-74 years at baseline in 2011-2013. A self-administered questionnaire requested information on body size, including height, weight, and waist circumference (the values of which were validated by direct measurement), socio-demographics, lifestyle, and disease history. BMI was calculated and categorized as < 18.5 (underweight), 18.5-20.6 (low-normal), 20.7-22.7 (mid-normal), 22.8-24.9 (high-normal), 25.0-24.9 (overweight), and≥30.0 kg/m2 (obese). Incident cases of dementia were obtained from the long-term care insurance database. A Cox proportional hazards model was used to calculate multivariable-adjusted hazard ratios (HRs). RESULTS: The mean age of participants was 59.0 years. In men, higher BMI was associated with lower dementia risk (fully-adjusted p for trend = 0.0086). In women, the association between BMI and dementia risk was U-shaped; the "underweight," "low-normal," and "overweight" groups had a significantly higher risk (fully-adjusted HR = 2.12, 2.08, and 1.78, respectively) than the reference ("high-normal" group). These findings did not change after excluding dementia cases which occurred within the first four years of the follow-up period. CONCLUSION: Overweight/obese women, but not men, had an increased risk of dementia, suggesting that sex differences in adiposity might be involved in the development of dementia.

DOI： 10.3233/JAD-230294

Low plasma 25-hydroxyvitamin D levels are associated with an increased risk of depressive symptoms in community-dwelling Japanese people aged between 40 and 74 years: The Murakami cohort study. International journal

Aya Hinata, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Toshiko Saito, Akemi Takahashi, Ribeka Takachi, Ryosaku Kobayashi, Rieko Oshiki, Masayuki Iki, Shoichiro Tsugane, Ayako Sasaki, Kei Watanabe, Kazutoshi Nakamura

Journal of affective disorders 325 48 - 54 2023.1

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Association between vitamin D levels and the occurrence of depression are not always consistent. The present cohort study aimed to determine this association in older adults, using a method for measuring vitamin D levels which is more accurate than those used in previous studies. METHODS: Participants were 3447 individuals aged 40-74 years without depressive symptoms at baseline who participated in the 5-year follow-up survey. The baseline investigation, including a self-administered questionnaire survey and blood collection, was conducted in 2011-2013. Plasma 25-hydroxyvitamin D (25[OH]D) levels were measured, and divided into overall quartiles summed up by sub-quartiles and stratified by age, sex, and season. The outcome was depressive symptoms determined by the CES-D (11-item, cut-off score of 6/7) 5 years later. Covariates were demographics, lifestyles, baseline CES-D score, and disease history. RESULTS: Mean plasma 25(OH)D levels were 58.0 nmol/L in men and 45.7 in women (P < 0.0001), and cumulative incidences of depressive symptoms were 249/1577 (15.8 %) in men and 313/1870 (16.7 %) in women (P = 0.4526). The lower 25(OH)D quartile group had higher adjusted ORs in men and women combined (P for trend = 0.0107) and women (P for trend = 0.0003), but not in men. Adjusted ORs of the lowest quartile group were significantly higher than the highest group in men and women combined (OR = 1.39, 95 % CI: 1.06-1.81) and women (OR = 1.89, 95 % CI: 1.31-2.72). LIMITATION: Depressive symptoms were self-reported. CONCLUSIONS: Low vitamin D levels were associated with a high risk of depressive symptoms, especially in women. Women are thus considered a major target for preventing vitamin D deficiency to address depression.

DOI： 10.1016/j.jad.2022.12.104

Urinary proteome profiles associated with cognitive decline in community elderly residents-A pilot study. International journal

Yumi Watanabe, Yoshitoshi Hirao, Kensaku Kasuga, Kaori Kitamura, Kazutoshi Nakamura, Tadashi Yamamoto

Frontiers in neurology 14 1134976 - 1134976 2023

Language：English Publishing type：Research paper (scientific journal)

Non-invasive and simple methods enabling easy identification of individuals at high risk of cognitive decline are needed as preventive measures against dementia. This pilot study aimed to explore protein biomarkers that can predict cognitive decline using urine, which can be collected non-invasively. Study subjects were selected from participants in a cohort study of middle-aged and older community-dwelling adults who underwent cognitive testing using the Mini-Mental State Examination and provided spot urine samples at two time points with an interval of approximately 5 years. Seven participants whose cognitive function declined 4 or more points from baseline (Group D) and 7 sex- and age-matched participants whose cognitive function remained within the normal range during the same period (Group M) were selected. Urinary proteomics using mass spectrometry was performed and discriminant models were created using orthogonal partial least squares-discriminant analysis (OPLS-DA). OPLS-DA yielded two models that significantly discriminated between the two groups at baseline and follow-up. Both models had ORM1, ORM2, and SERPINA3 in common. A further OPLS-DA model using baseline ORM1, ORM2, and SERPINA3 data showed similar predictive performance for data at follow-up as it did for baseline data (sensitivity: 0.85, specificity: 0.85), with the receiver operating characteristic curve analysis yielding an area under the curve of 0.878. This prospective study demonstrated the potential for using urine to identify biomarkers of cognitive decline.

DOI： 10.3389/fneur.2023.1134976

Cataract Surgery and Chronic Kidney Disease: A Hospital-based Prospective Cohort Study

Minako Wakasugi, Akio Yokoseki, Masakazu Wada, Takaiko Yoshino, Takeshi Momotsu, Kenji Sato, Hiroyuki Kawashima, Kazutoshi Nakamura, Takeo Fukuchi, Osamu Onodera, Ichiei Narita

Internal Medicine 2023

アルツハイマー病患者尿中におけるグリセロリン脂質代謝関連代謝物の変動

渡邊裕美, 春日健作, 徳武孝允, 北村香織, 池内健, 中村和利

老年精神医学雑誌 33 ( 増刊II ) 261 - 261 2022.11

Correction: Physical activity and recurrent fall risk in community-dwelling Japanese people aged 40-74 years: the Murakami cohort study. International journal

Shoto Kamimura, Takashi Iida, Yumi Watanabe, Kaori Kitamura, Keiko Kabasawa, Akemi Takahashi, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Ribeka Takachi, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

European review of aging and physical activity : official journal of the European Group for Research into Elderly and Physical Activity 19 ( 1 ) 25 - 25 2022.10

アルツハイマー病患者尿中におけるグリセロリン脂質代謝関連代謝物の変動

渡邊裕美, 春日健作, 徳武孝允, 北村香織, 池内健, 中村和利

Dementia Japan 36 ( 4 ) 760 - 760 2022.10

Dietary sodium sources according to four 3-day weighed food records and their association with multiple 24-hour urinary excretions among middle-aged and elderly Japanese participants in rural areas. International journal

Fuyuka Ogawa, Ribeka Takachi, Junko Ishihara, Marina Yamagishi, Sachiko Maruya, Yuri Ishii, Kumiko Kito, Kazutoshi Nakamura, Junta Tanaka, Taiki Yamaji, Hiroyasu Iso, Motoki Iwasaki, Shoichiro Tsugane, Norie Sawada

The British journal of nutrition 129 ( 11 ) 1 - 23 2022.8

Language：English Publishing type：Research paper (scientific journal)

Reducing sodium (Na) intake is an urgent global challenge, especially in East Asia and high-income Asia-Pacific regions. However, the sources of Na and their effects on urinary Na excretion have not been fully studied. We sought to clarify these sources and their association with urinary Na excretion. We examined four 3-day weighed food records and five 24-h urinary collections from each of 253 participants in Japan, aged 35-80 years, between 2012 and 2013. We compared the levels of Na according to four categories: foods contributing to discretionary or nondiscretionary Na intake, the situation in which dishes were cooked and consumed, food groups and types of cuisine. We also conducted regression analysis in which 24-h urinary Na excretion was a dependent variable and the amounts of food intake in the four categories were independent variables. Levels of Na were the highest in discretionary intake (60.6%) and in home-prepared dishes (84.0%). Of the food groups, miso soup showed the highest percentage contribution to Na intake (13.3%) after seasonings such as soy sauce. In the regression analysis, the standardised coefficient for foods of nondiscretionary Na sources was larger than that for discretionary sources, whereas that for home-prepared dishes was consistent with the levels of Na in those foods. Pickled products, followed by fresh fish and shellfish, miso soup and rice, were associated with high urinary Na excretion. Thus, discretionary foods (such as miso soup) contribute the most to Na consumption, although nondiscretionary intake (such as pickled vegetables) may influence urinary Na excretion.

DOI： 10.1017/S0007114522002653

Leisure-Time and Non-Leisure-Time Physical Activities are Dose-Dependently Associated With a Reduced Risk of Dementia in Community-Dwelling People Aged 40-74 Years: The Murakami Cohort Study. International journal

Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Akemi Takahashi, Toshiko Saito, Ryosaku Kobayashi, Ribeka Takachi, Rieko Oshiki, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

Journal of the American Medical Directors Association 23 ( 7 ) 1197 - 1204 2022.7

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: Although physical activity (PA) in late life is considered a preventive factor for dementia, effects of different types of PAs on the development of dementia in early old age are unclear. This study aimed to determine the effect of leisure-time and non-leisure-time PAs on dementia risk in middle-aged and older adults during an 8-year follow-up. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: Participants were 13,773 community-dwelling individuals aged 40-74 years who completed the baseline self-administered questionnaire survey of the Murakami cohort study in 2011-2013. METHODS: Main predictors were leisure-time and non-leisure-time (commute, occupational work, and housework) PAs as assessed by MET score (MET-hour/d). The outcome was newly developed dementia determined using a long-term care insurance database. Covariates included demographics, lifestyle, body size, disease history, and PA level. Hazard ratios (HRs) were calculated using Cox proportional hazards models. RESULTS: Mean age of participants was 59.0 (SD 9.3) years. Higher levels of leisure-time PA were associated with lower HRs (adjusted P for trend <.001), with all tertiles having significantly lower HRs (low: 0.71, 95% CI 0.51-0.99; medium: 0.59, 95% CI 0.43-0.81; high: 0.55, 95% CI 0.41-0.75) relative to the reference (zero). Higher quartiles of non-leisure-time PA were associated with lower adjusted HRs for dementia (adjusted P for trend < .001), with the second-fourth quartiles having significantly lower HRs (second: 0.73, 95% CI 0.54-0.98; third: 0.59, 95% CI 0.43-0.81; fourth: 0.55, 95% CI 0.41-0.75) relative to the lowest quartile. These associations were robust regardless of sex and age group. CONCLUSIONS AND IMPLICATIONS: Both leisure-time and non-leisure-time PAs are independently and robustly associated with a reduced risk of dementia.

DOI： 10.1016/j.jamda.2022.01.053

Validity of the Food Frequency Questionnaire-Estimated Intakes of Sodium, Potassium, and Sodium-to-Potassium Ratio for Screening at a Point of Absolute Intake among Middle-Aged and Older Japanese Adults. International journal

Tomoka Matsuno, Ribeka Takachi, Junko Ishihara, Yuri Ishii, Kumiko Kito, Sachiko Maruya, Kazutoshi Nakamura, Junta Tanaka, Kazumasa Yamagishi, Taiki Yamaji, Hiroyasu Iso, Motoki Iwasaki, Shoichiro Tsugane, Norie Sawada

Nutrients 14 ( 13 ) 2022.6

Language：English Publishing type：Research paper (scientific journal)

Using Food Frequency Questionnaires (FFQs) to compare dietary references for screening has been in high demand. However, FFQs have been widely used for ranking individuals in a population based on their dietary intake. We determined the validity of sodium (salt equivalent) intake, potassium intake, and sodium-to-potassium (Na/K) ratio obtained using the FFQ for identifying individuals who deviated from the dietary reference intakes (DRIs) measured using multiple 24-h urinary excretion measurements or 12-day weighed food records (WFR). This study included 235 middle-aged subjects. The correlation coefficients (CCs) between the FFQ and WFR estimates were mostly moderate (0.24-0.54); the CCs between the FFQ and 24-h urinary excretion measurements were low or moderate (0.26-0.38). Values of area under the receiver-operating curve (AUC) at the point of DRIs for salt equivalent or potassium were >0.7 with the WFR as the reference standard and 0.60-0.76 with the 24-h urinary excretion as the reference standard. Using both standard measures, the AUC for the Na/K ratio was <0.7. The accuracy of salt equivalent and potassium intake estimation using the FFQ to determine absolute intake point was comparable to that using WFR, allowing for quantified error, but not as good as that of 24-h urinary excretion.

DOI： 10.3390/nu14132594

Association between Sarcopenia and Depressive Symptoms in Community-Dwelling People Aged 40 Years and Older.

Alena Zakharova, Keiko Kabasawa, Yumi Ito, Junta Tanaka, Aya Hinata, Kaori Kitamura, Yumi Watanabe, Shoichiro Tsugane, Kazutoshi Nakamura, Ichiei Narita

The Tohoku journal of experimental medicine 257 ( 2 ) 117 - 125 2022.6

Language：English Publishing type：Research paper (scientific journal)

Several studies have reported an association between sarcopenia and depression. Their results, however, are inconsistent, partly due to small sample sizes and lack of consideration of important confounders. The present study aimed to cross-sectionally examine this association in community-dwelling people in Japan. This study used baseline data from the Yuzawa cohort study (age ≥ 40 years), with the final analysis population comprising 2,466 participants. A self-administered questionnaire was used to elicit information related to sarcopenia, depressive symptoms, demographic characteristics, anthropometrics, disease history, and lifestyles. Sarcopenia was diagnosed using SARC-F, a validated questionnaire including components of Strength, Assistance in walking, Rising from a chair, Climbing stairs, and Falls. Depressive symptoms were assessed using the 11-item version of the Center for Epidemiologic Studies Depression Scale (CES-D). For depressive symptoms, prevalence ratios (PRs) were calculated, and odds ratio (ORs) were obtained using simple and multiple logistic regression analyses. Mean age of participants was 61.7 years (standard deviation = 11.8), and 10.5% and 34.7% had sarcopenia and depressive symptoms, respectively. Sarcopenic individuals had a significantly higher PR (2.00), unadjusted OR (3.67), and adjusted OR (4.96) compared to non-sarcopenic individuals, with an estimated adjusted PR of 2.7. There was a significant dose-dependent association between SARC-F scores and depressive symptoms in sarcopenic individuals (adjusted P for trend = 0.0028). In conclusion, sarcopenia and depressive symptoms were robustly associated in community-dwelling, middle-aged and older people in Japan. However, the direction of this association is unclear, and a future cohort study will be needed to determine causality.

DOI： 10.1620/tjem.2022.J024

アルツハイマー病患者尿中代謝産物の網羅的解析

渡邊裕美, 春日健作, 徳武孝允, 北村香織, 池内健, 中村和利

日本衛生学雑誌 77 ( Suppl. ) S204 - S204 2022.3

Associations of Urinary and Dietary Sodium-To-Potassium Ratios with Albuminuria in Community-Dwelling Japanese Adults: A Cross-Sectional Study. International journal

Keiko Kabasawa, Ribeka Takachi, Kazutoshi Nakamura, Norie Sawada, Shoichiro Tsugane, Yumi Ito, Junta Tanaka, Ichiei Narita, Kunihiro Matsushita

Kidney & blood pressure research 47 ( 9 ) 576 - 585 2022

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: The urinary sodium-to-potassium ratio is an indicator of dietary sodium intake and has been associated with reduced kidney function. However, less is known about its association with albuminuria, the other key component of chronic kidney disease, in the community-dwelling adult population. We examined the association of the spot urinary sodium-to-potassium ratio with albuminuria and compared spot urinary and dietary sodium-to-potassium ratios. METHODS: We quantified the association of the urinary sodium-to-potassium ratio with albuminuria in 6,274 Japanese adults (aged 40-97 years; 50.9% women) based on spot urine samples. We performed linear and logistic regression modeling to account for potential confounders. Elevated albuminuria was defined as a spot urinary albumin-to-creatinine ratio (ACR) ≥30 mg/g. We secondarily evaluated the dietary sodium-to-potassium ratio based on a food-frequency questionnaire. RESULTS: The median spot urinary and dietary sodium-to-potassium ratios were 2.70 (interquartile interval, 1.87-3.83) and 1.50 (1.21-1.84), respectively. The median ACR was 11.0 (6.0-24.0) mg/g. In a multivariable linear regression model, the spot urinary sodium-to-potassium ratio (per increment) was significantly associated with the natural logarithm of the ACR (regression coefficient, 0.023 [95% confidence interval {95% CI}, 0.007-0.038]). This result was consistent in a multivariable logistic regression model (adjusted odds ratio, 1.08 [95% CI: 1.04-1.12]). The corresponding estimates for the dietary sodium-to-potassium ratio were 0.139 (95% CI: 0.087-0.191) and 1.28 (95% CI: 1.14-1.45), respectively. CONCLUSIONS: Both spot urinary and dietary sodium-to-potassium ratios were associated with elevated albuminuria in community-dwelling Japanese adults. Our findings further support the potential usefulness of the spot urinary sodium-to-potassium ratio as an indicator of sodium intake and suggest a link between sodium intake and kidney damage.

DOI： 10.1159/000526277

Secular changes in bone mineral density of adult Japanese women from 1995 to 2013.

Hiroaki Watanabe, Yasuko Minagawa, Ichiro Suzuki, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Kseniia Platonova, Aya Hinata, Kazutoshi Nakamura

Fukushima journal of medical science 67 ( 3 ) 128 - 134 2021.12

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Secular changes in hip fracture incidence have been reported in the last few decades in Japan, but whether long-term bone mineral density (BMD) is also changing is unclear. This study aimed to determine whether BMD of Japanese women has changed over time. METHODS: Subjects were 10,649 adult women who underwent BMD measurement in a health check-up population in Niigata, Japan, between 1995 and 2013. BMD of the distal, non-dominant forearm was measured by dual-energy X-ray absorptiometry. Demographic information and BMI were also obtained. Secular trends were determined by linear regression analysis. RESULTS: BMD of subjects in their 40's decreased significantly in the age-adjusted model (P for trend=0.0162), but not in the age- and BMI-adjusted model (P for trend=0.2171). BMD of subjects in their 50's decreased marginally in the age-adjusted model (P for trend=0.0535), but not in the age- and BMI-adjusted model (P for trend=0.6601). BMDs of subjects in their 30's and 60's did not significantly change, while BMIs of subjects in their 40's-60's decreased significantly. CONCLUSIONS: A secular decrease in BMD, partly attributed to decreases in BMI, was observed in middle-aged Japanese women from 1995 to 2013. Measures to help maintain suitable BMI will be necessary to prevent a decrease in BMD among women.

DOI： 10.5387/fms.2021-10

Serum 25-hydroxyvitamin D levels are not associated with impaired postural sway in community-dwelling older women: a 6-year follow-up study. International journal

Kazutoshi Nakamura, Toshiko Saito, Akemi Takahashi, Ryosaku Kobayashi, Rieko Oshiki, Kaori Kitamura, Yumi Watanabe

Journal of musculoskeletal & neuronal interactions 21 ( 4 ) 501 - 508 2021.12

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: A positive association between levels of blood 25-hydroxyvitamin D (25[OH]D), an index of vitamin D status, and physical balance has been reported from cross-sectional studies, but longitudinal studies are rare. The present study aimed to test the hypothesis that low serum 25(OH)D levels are longitudinally associated with impaired postural sway over a 6-year follow-up period in older women. METHODS: The present cohort consisted of 392 community-dwelling Japanese women aged ≥69 years. Baseline examinations included serum 25(OH)D and physical performance tests, including postural sway velocity. Standing postural sway was evaluated by measuring gravity-center sway velocity. Follow-up physical performance tests were conducted 6 years later. RESULTS: Mean subject age and serum 25(OH)D levels were 73.3 years (SD 3.7) and 61.0 nmol/L (SD 16.9), respectively. No significant association was found between 25(OH)D levels and changes in postural sway velocity (adjusted P for trend=0.72). Women with 25(OH)D <30 nmol/L tended to have lower Δpostural sway velocity than those with 25(OH)D ≥30 nmol/L (mean, -0.59 vs 0.37 cm/s, respectively; adjusted P=0.13). CONCLUSIONS: Vitamin D levels are not longitudinally associated with impaired postural sway in older women. Further longitudinal studies are needed to corroborate the results of this study.

Short daytime napping reduces the risk of cognitive decline in community-dwelling older adults: a 5-year longitudinal study

Kaori Kitamura, Yumi Watanabe, Kazutoshi Nakamura, Chikako Takano, Naomi Hayashi, Hisami Sato, Toshiyuki Someya

BMC Geriatrics 21 ( 1 ) 2021.12

Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

<title>Abstract</title><sec>
<title>Background</title>
Beneficial effects of napping on cognition have been suggested in cross-sectional studies. This study aimed to clarify longitudinal associations between cognitive decline and sleep characteristics, particularly daytime napping, over a 5-year period in older adults.

</sec><sec>
<title>Methods</title>
Study participants were 389 community-dwelling individuals aged ≥65 years living in Ojiya City, Niigata, Japan. Baseline and follow-up examinations were conducted in 2011–2013 and 2016–2018, respectively. Trained nurses visited and interviewed participants to collect the following information at baseline and follow-up: demographic characteristics, disease history, lifestyle habits including bedtime, sleeping hours, and daytime nap duration, and cognitive function. The assessment of cognitive function was performed using the revised Hasegawa’s dementia scale (HDS-R), with cognitive decline defined as a change in the HDS-R of ≤ − 3 over 5 years. Odds ratios (ORs) for cognitive decline were calculated using multiple logistic regression analysis.

</sec><sec>
<title>Results</title>
Mean age of participants was 74.6 years (SD 6.4), and the cumulative incidence of cognitive decline was 106/389 (27.3%). The adjusted OR for 1–29 min daytime napping was significantly lower compared to that for no napping (OR = 0.47, 95%CI: 0.23–0.96). Earlier bedtime was associated with cognitive decline (adjusted P for trend = 0.0480).

</sec><sec>
<title>Conclusion</title>
Short daytime napping (< 30 min) reduces the risk of cognitive decline over 5 years for community-dwelling older people. A future study will be necessary to confirm the effect of short napping on the reduction of risk for clinically diagnosed dementia.

</sec>

DOI： 10.1186/s12877-021-02418-0

Other Link： https://link.springer.com/article/10.1186/s12877-021-02418-0/fulltext.html

中高年者の5年間の生活習慣の変化村上コホート研究

中村和利, 北村香織, プラトノバ・クセニア, 渡邊裕美

新潟医学会雑誌 135 ( 10-12 ) 213 - 219 2021.12

Language：Japanese Publisher：新潟医学会

著者らは、村上コホート研究のベースライン調査と5年後フォローアップ調査において、自記式の調査票により、生活習慣、病歴などの情報を得た。この縦断データを利用し、中高年の喫煙、飲酒、運動の習慣の5年間の変化と、禁煙、節酒、運動の習慣の獲得に関わる要因について検討した。対象者は5年後フォローアップ調査に参加した8,487人で、ベースライン調査時の年齢は40から74歳であった。ベースライン調査票の利用項目は、性、年齢、婚姻歴、学歴、職業、現在の健康状態、病歴(がん、心筋梗塞、脳卒中、糖尿病)、現在の喫煙の有無、飲酒頻度、余暇での運動の頻度、肥満度(Body mass index)であった。5年後フォローアップ調査票の利用項目は、現在の喫煙の有無、飲酒頻度、余暇での運動の頻度であり、これらの項目をベースライン時と5年後で比較した。また、ベースライン時に喫煙者、毎日の飲酒者、または余暇での運動の習慣のない人(<1回/週)について、5年後にこれらの習慣がよい方向に変化した人、すなわち禁煙、毎日の飲酒中止、週に1回以上の運動開始した人のベースライン時の要因(予測要因)を解析した。ベースラインと5年後の比較では、喫煙と飲酒については全体的に禁煙・節酒の方向に変化する傾向が見られたものの、運動の習慣については明確な変化が見られなかった。好ましくない喫煙、飲酒、運動の習慣を持つ人の生活習慣改善に関わる要因を解析した結果、いずれの習慣も高齢であるほど改善する傾向が見られた。飲酒習慣の変化には体調不良の関与が、運動の習慣の獲得には教育の重要性が示唆されたが、禁煙に関しては加齢以外の関連要因を見いだせなかった。今後の慢性疾患の予防対策にこれらの情報が活用されることを期待する。(著者抄録)

Other Link： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2021&ichushi_jid=J00990&link_issn=&doc_id=20220705060001&doc_link_id=http%3A%2F%2Fhdl.handle.net%2F10191%2F0002000703&url=http%3A%2F%2Fhdl.handle.net%2F10191%2F0002000703&type=%90V%8A%83%91%E5%8Aw%81F%90V%8A%83%91%E5%8Aw%8Aw%8Fp%83%8A%83%7C%83W%83g%83%8A_Nuar&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F80230_3.gif

中高年者の5年間の生活習慣の変化村上コホート研究

中村和利, 北村香織, プラトノバ・クセニア, 渡邊裕美

新潟医学会雑誌 135 ( 10-12 ) 213 - 219 2021.12

Language：Japanese Publisher：新潟医学会

著者らは、村上コホート研究のベースライン調査と5年後フォローアップ調査において、自記式の調査票により、生活習慣、病歴などの情報を得た。この縦断データを利用し、中高年の喫煙、飲酒、運動の習慣の5年間の変化と、禁煙、節酒、運動の習慣の獲得に関わる要因について検討した。対象者は5年後フォローアップ調査に参加した8,487人で、ベースライン調査時の年齢は40から74歳であった。ベースライン調査票の利用項目は、性、年齢、婚姻歴、学歴、職業、現在の健康状態、病歴(がん、心筋梗塞、脳卒中、糖尿病)、現在の喫煙の有無、飲酒頻度、余暇での運動の頻度、肥満度(Body mass index)であった。5年後フォローアップ調査票の利用項目は、現在の喫煙の有無、飲酒頻度、余暇での運動の頻度であり、これらの項目をベースライン時と5年後で比較した。また、ベースライン時に喫煙者、毎日の飲酒者、または余暇での運動の習慣のない人(<1回/週)について、5年後にこれらの習慣がよい方向に変化した人、すなわち禁煙、毎日の飲酒中止、週に1回以上の運動開始した人のベースライン時の要因(予測要因)を解析した。ベースラインと5年後の比較では、喫煙と飲酒については全体的に禁煙・節酒の方向に変化する傾向が見られたものの、運動の習慣については明確な変化が見られなかった。好ましくない喫煙、飲酒、運動の習慣を持つ人の生活習慣改善に関わる要因を解析した結果、いずれの習慣も高齢であるほど改善する傾向が見られた。飲酒習慣の変化には体調不良の関与が、運動の習慣の獲得には教育の重要性が示唆されたが、禁煙に関しては加齢以外の関連要因を見いだせなかった。今後の慢性疾患の予防対策にこれらの情報が活用されることを期待する。(著者抄録)

Other Link： https://search.jamas.or.jp/default/link?pub_year=2021&ichushi_jid=J00990&link_issn=&doc_id=20220705060001&doc_link_id=%2Fdg3nigta%2F2021%2F013510%2F001%2F0213-0219%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fdg3nigta%2F2021%2F013510%2F001%2F0213-0219%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Education, household income, and depressive symptoms in middle-aged and older Japanese adults. International journal

Aya Hinata, Keiko Kabasawa, Yumi Watanabe, Kaori Kitamura, Yumi Ito, Ribeka Takachi, Shoichiro Tsugane, Junta Tanaka, Ayako Sasaki, Ichiei Narita, Kazutoshi Nakamura

BMC public health 21 ( 1 ) 2120 - 2120 2021.11

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Income inequality has dramatically increased worldwide, and there is a need to re-evaluate the association between socio-economic status (SES) and depression. Relative contributions of household income and education to depression, as well as their interactions, have not been fully evaluated. This study aimed to examine the association between SES and depressive symptoms in Japanese adults, focusing on interactions between education and household income levels. METHODS: This cross-sectional study used data from baseline surveys of two cohort studies. Participants were 38,499 community-dwelling people aged 40-74 years who participated in baseline surveys of the Murakami cohort study (2011-2012) and Uonuma cohort study (2012-2015) conducted in Niigata Prefecture, Japan. Information regarding marital status, education level, household income, occupation, activities of daily living (ADL), and history of cancer, myocardial infarction, stroke, and diabetes was obtained using a self-administered questionnaire. Depressive symptoms were examined using the Center for Epidemiologic Studies Depression Scale (CES-D). Logistic regression analysis was used to obtain odds ratios (ORs). Covariates included age, sex, marital status, education, household income, occupation, ADL, and disease history. RESULTS: Individuals with higher education levels had lower ORs (adjusted P for trend = 0.0007) for depressive symptoms, independently of household income level. The OR of the university-or-higher group was significantly lower than that of the junior high school group (adjusted OR = 0.79). Individuals with lower household income levels had higher ORs (adjusted P for trend< 0.0001) for depressive symptoms, independently of education level. The type of occupation was not associated with depressive symptoms. In subgroup analyses according to household income level, individuals with higher education levels had significantly lower ORs in the lowest- and lower-income groups (adjusted P for trend = 0.0275 and 0.0123, respectively), but not in higher- and highest-income groups (0.5214 and 0.0915, respectively). CONCLUSIONS: Both education and household income levels are independently associated with the prevalence of depressive symptoms, with household income levels showing a more robust association with depressive symptoms than education levels. This suggests that a high household income level may offset the risk of depressive symptoms from having a low education level.

DOI： 10.1186/s12889-021-12168-8

Association of coffee, green tea, and caffeine with the risk of dementia in older Japanese people. International journal

Nana Matsushita, Yuta Nakanishi, Yumi Watanabe, Kaori Kitamura, Keiko Kabasawa, Akemi Takahashi, Toshiko Saito, Ryosaku Kobayashi, Ribeka Takachi, Rieko Oshiki, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

Journal of the American Geriatrics Society 2021.10

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: Coffee, green tea, and caffeine are potential preventive factors for dementia, but the underlying evidence is insufficient. This study aimed to examine associations between the consumption of coffee, green tea, and caffeine and dementia risk in middle-aged and older people. METHODS: This was a cohort study with an 8.0-year follow-up. Participants were community-dwelling individuals (n = 13,757) aged 40-74 years. A self-administered questionnaire survey was conducted in 2011-2013. Predictors were the consumption of coffee/green tea, from which caffeine consumption was estimated. The outcome was incident dementia obtained from the long-term care insurance database. Covariates were demographic factors, body mass index, physical activity, energy, smoking, drinking, and disease history. Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. HRs were also calculated using a Cox model with delayed entry. RESULTS: The number of dementia cases during the study period was 309. Participants with higher coffee consumption had lower HRs (adjusted p for trend = 0.0014), with the fifth quintile (≥326 ml/day) having a significantly lower HR (0.49, 95% confidence interval [CI]: 0.30-0.79) than the first quintile (<26 ml/day, reference). Similarly, participants with higher caffeine consumption had a significantly lower HR (adjusted p for trend = 0.0004) than the reference. The Cox model with delayed entry yielded similar results. These associations were significant in men, but not in women. Moreover, participants who consumed 2-2.9 cups/day and ≥3 cups/day of coffee had lower HRs (0.69, 95% CI: 0.48-0.98 and 0.53, 95% CI: 0.31-0.89, respectively) than those who consumed 0 cup/day. The association between green tea consumption and reduced dementia risk was significant (adjusted p for trend = 0.0146) only in the 60-69 years age subgroup. CONCLUSIONS: High levels of coffee and caffeine consumption were significantly associated with a reduced dementia risk in a dose-dependent manner, especially in men. Moreover, coffee consumption of ≥3 cups/day was associated with a 50% reduction in dementia risk.

DOI： 10.1111/jgs.17407

Menstrual and reproductive factors and limitations in activities of daily living: A case-control study within the Japan Public Health Center-based Prospective Study. Reviewed International journal

Kazutoshi Nakamura, Norie Sawada, Kaori Kitamura, Yumi Watanabe, Shoichiro Tsugane

The journal of obstetrics and gynaecology research 47 ( 11 ) 3903 - 3912 2021.9

Language：English Publishing type：Research paper (scientific journal)

AIM: Although menstrual/reproductive factors are known to be associated with physical disability, little is known about these associations in relation to activities of daily living (ADL). This study aimed to clarify associations between menstrual/reproductive factors and ADL limitations in peri- and postmenopausal women. STUDY DESIGN: A nested case-control study of the Japan Public Health Center-based Prospective (JPHC) Study. METHODS: The main outcome measure was self-reported ADL levels in the 10-year follow-up questionnaire survey of the JPHC Study conducted between 2000 and 2004 (N = 36 460). Women who "live inside almost independently, but go out with assistance" or had a lower level of activity were considered to have ADL limitations ("cases"), and all others served as controls. Candidate menstrual/reproductive predictors were as follows: menarcheal age, menopausal status, menopausal age, regularity of menses, menstrual cycle, number of pregnancies, age at first pregnancy, number of deliveries, age at first delivery, and breast feeding. Multiple logistic regression analyses were conducted, and odds ratios adjusted for age and past lifestyle were calculated. RESULTS: Mean ages of cases (N = 592) and controls (N = 38 656) were 68.3 (SD = 7.6) and 61.1 (SD = 7.7) years, respectively. With respect to menopausal age, groups aged <45 and ≥55 years had significantly higher adjusted ORs (1.44, 95% CI: 1.09-1.90 and 1.55, 95%CI: 1.09-2.18, respectively) than the reference group (50-54 years). Multiparous women had significantly lower ORs than nulliparous women. CONCLUSION: Our findings suggest that menopausal age and parity may predict future ADL limitations in women.

DOI： 10.1111/jog.14959

A 5-year longitudinal association between dietary fermented soya bean (natto) intake and tooth loss through bone mineral density in postmenopausal women: The Yokogoshi cohort study

Masanori Iwasaki, Misuzu Sato, Akihiro Yoshihara, Toshiko Saito, Kaori Kitamura, Toshihiro Ansai, Kazutoshi Nakamura

Gerodontology 38 ( 3 ) 267 - 275 2021.9

Publishing type：Research paper (scientific journal)

Objective: In this 5-year cohort study, we aimed to determine whether the intake of natto, a fermented soya bean food product, has an indirect effect on tooth loss incidence through BMD changes among postmenopausal women. Background: Evidence indicates (1) that natto has a beneficial effect on bone health and (2) that a decrease in bone mineral density (BMD) is associated with tooth loss. Methods: The study recruited 435 postmenopausal women (average age = 64.2 years). Natto intake (exposure) was assessed at baseline using a food frequency questionnaire. Lumbar spine BMD and number of teeth were measured at baseline and 5-year follow-up. BMD change (mediator) and the number of teeth lost (outcome) over time were calculated. The mediation model consisted of these 3 variables. Mediation analysis was performed to test the indirect effect of the natto intake measured through BMD change on tooth loss. Results: During the study, the mean number of teeth lost was 1.2 (standard deviation = 1.8), and the mean BMD decline was 2.5% (standard deviation = 7.1). After adjusting for potential confounders, increasing habitual natto intake was significantly indirectly associated with a lower incidence of tooth loss mediated by BMD change (incidence rate ratio of tooth loss among women with “≥1 pack/day” natto intake was 0.90 [95% confidence interval = 0.82-0.99] compared to those with natto consumption of “rarely”). Conclusions: Dietary natto intake is significantly indirectly associated with a lower incidence of tooth loss among postmenopausal women, and systemic bone density could be a mediator of this association.

DOI： 10.1111/ger.12523

Validity of dietary isothiocyanate intake estimates from a food frequency questionnaire using 24 h urinary isothiocyanate excretion as an objective biomarker: the JPHC-NEXT protocol area. Reviewed International journal

Nagisa Mori, Norie Sawada, Junpei Yamamoto, Junko Ishihara, Taichi Shimazu, Ribeka Takachi, Utako Murai, Kazutoshi Nakamura, Junta Tanaka, Taiki Yamaji, Motoki Iwasaki, Hiroyasu Iso, Masuko Kobori, Shoichiro Tsugane

European journal of clinical nutrition 76 ( 3 ) 462 - 468 2021.7

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND/OBJECTIVES: Isothiocyanate (ITC) is formed via the hydrolysis of glucosinolates by myrosinase, found in cruciferous vegetables. Although myrosinase is inactivated by the cooking process, no studies have incorporated the effect of cooking into the estimation of dietary ITC intake or evaluated the validity. We evaluated the validity of dietary ITC intake estimated from a food frequency questionnaire (FFQ), and urinary ITC levels using 24 h urine samples or a WFR (weighed food record), and evaluated the reproducibility of dietary ITC in two FFQs administered at an interval of 1-year. SUBJECTS/METHODS: The JPHC-NEXT Protocol Area included a total of 255 middle-aged participants across Japan. We calculated dietary ITC intake from WFR and two FFQs by assuming that cooked cruciferous vegetables contain zero ITC. Urinary ITC excretion was measured at two points during summer and winter. The validity and reproducibility of dietary ITC intake estimated by FFQ were assessed using Spearman's correlation coefficients. RESULTS: Although we observed a moderate correlation between dietary ITC intake derived from a 12-day WFR and urinary ITC excretion, notwithstanding the cooking process, the correlation between dietary ITC intake estimated by FFQ and mean urinary ITC excretion was low. However, the correlation was improved when we compared urinary ITC excretion and a 3-day WFR or FFQ collected during winter. Our FFQ showed good reproducibility. CONCLUSION: Although seasonality is a critical factor, dietary ITC intake estimated using an FFQ showed moderate validity and reproducibility and can be used in future epidemiological studies.

DOI： 10.1038/s41430-021-00970-x

Body mass index and risk of recurrent falls in community-dwelling Japanese aged 40-74 years: The Murakami cohort study.

Kazutoshi Nakamura, Kaori Kitamura, Yumi Watanabe, Keiko Kabasawa, Akemi Takahashi, Aya Hinata, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Ribeka Takachi, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Osamu Yamazaki, Kei Watanabe

Geriatrics & gerontology international 21 ( 6 ) 498 - 505 2021.6

Language：English Publishing type：Research paper (scientific journal)

AIMS: A prior meta-analysis found that obesity (body mass index [BMI] ≥ 30 kg/m2 ) was associated with a high fall risk, while being overweight (BMI≥25, <30 kg/m2 ) was associated with the lowest fall risk. However, whether these associations hold true for East Asians is unknown. This study aimed to assess the association between BMI and incidence of recurrent falls in Japanese aged 40-74 years. METHODS: This 5-year follow-up cohort study involved 7538 community-dwelling individuals who did not experience recurrent falls in the year before the baseline study. Information on demographics, body size, lifestyle, and disease history was obtained using a self-administered questionnaire. BMI was categorized as <18.5 (underweight), 18.5-20.6 (low-normal), 20.7-22.7 (mid-normal, reference), 22.8-24.9 (high-normal), and ≥ 25.0 kg/m2 (overweight). The outcome was recurrent falls reported, and fall history in the previous year was recorded as none, once, or twice or more (recurrent falls). RESULTS: Mean BMI was 23.5 kg/m2 (SD 2.9) for men and 22.7 kg/m2 (SD 3.2) for women. The adjusted odds ratio (OR) for recurrent falls in the BMI ≥25 group was significantly higher (1.41, 95%CI: 1.02-1.93) than that in the reference group. The adjusted OR in the BMI ≥25 group was significantly higher than that in the reference group for the age ≥ 60 subgroup (1.62, 95%CI: 1.09-2.40), but not for the age < 60 subgroup (OR = 1.04, 95%CI: 0.60-1.80). CONCLUSIONS: Being overweight may be a risk factor for recurrent falls in community-dwelling older Japanese. Further studies are needed to determine the underlying mechanism. Geriatr Gerontol Int 2021; 21: 498-505.

DOI： 10.1111/ggi.14167

Associations of physical activity in rural life with happiness and ikigai: a cross-sectional study Reviewed

Keiko Kabasawa, Junta Tanaka, Yumi Ito, Kinya Yoshida, Kaori Kitamura, Shoichiro Tsugane, Kazutoshi Nakamura, Ichiei Narita

Humanities and Social Sciences Communications 8 ( 1 ) 2021.2

Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

<title>Abstract</title>Physical activity is associated with subjective well-being. In rural communities, however, physical activity may be affected by environmental factors (e.g., nature and socioecological factors). We examined the association of two physical activities in rural life (farming activity and snow removal) with subjective well-being in terms of happiness and <italic>ikigai</italic> (a Japanese word meaning purpose in life). In this cross-sectional study, we analysed data collected from community-dwelling adults aged ≥ 40 years in the 2012–2014 survey of the Uonuma cohort study, Niigata, Japan. Happiness (<italic>n</italic> = 31,848) and <italic>ikigai</italic> (<italic>n</italic> = 31,785) were evaluated with respect to farming activity from May through November and snow removal from December through April by using an ordinal logistic regression model with adjustments for potential confounders. The analyses were conducted in 2019. Among the participants who reported some farming or snow-removal time, median farming and snow-removal time (minutes per day) was 90.0 and 64.3 for men and 85.7 and 51.4 for women, respectively. Ordinal logistic regression analysis showed that longer time farming was associated with greater happiness and <italic>ikigai</italic> in men (adjusted odds ratio for first vs. fourth quartile: happiness = 1.17, 95% confidence interval [CI] = 1.01, 1.35; <italic>ikigai</italic> = 1.29, 95% CI = 1.10, 1.50), and also in women (adjusted odds ratio for first vs. fourth quartile: happiness = 1.17, 95% CI = 1.001, 1.36; <italic>ikigai</italic> = 1.42, 95% CI = 1.20, 1.67). More snow-removal time was inversely associated with happiness and with <italic>ikigai</italic> in women only (adjusted odds ratio for first vs. fourth quartile: happiness = 0.75, 95% CI = 0.67, 0.85; <italic>ikigai</italic> = 0.78, 95% CI = 0.69, 0.88). Our findings showed that physical activity in rural life was associated with happiness and with <italic>ikigai</italic>, and gender differences were observed in their associations with more snow-removal time. These results may be useful in helping to identify people in rural communities who are vulnerable in terms of psychological well-being.

DOI： 10.1057/s41599-021-00723-y

Other Link： http://www.nature.com/articles/s41599-021-00723-y

Alterations in Glycerolipid and Fatty Acid Metabolic Pathways in Alzheimer's Disease Identified by Urinary Metabolic Profiling: A Pilot Study. Reviewed International journal

Yumi Watanabe, Kensaku Kasuga, Takayoshi Tokutake, Kaori Kitamura, Takeshi Ikeuchi, Kazutoshi Nakamura

Frontiers in neurology 12 719159 - 719159 2021

Language：English Publishing type：Research paper (scientific journal)

An easily accessible and non-invasive biomarker for the early detection of Alzheimer's disease (AD) is needed. Evidence suggests that metabolic dysfunction underlies the pathophysiology of AD. While urine is a non-invasively collectable biofluid and a good source for metabolomics analysis, it is not yet widely used for this purpose. This small-scale pilot study aimed to examine whether the metabolic profile of urine from AD patients reflects the metabolic dysfunction reported to underlie AD pathology, and to identify metabolites that could distinguish AD patients from cognitively healthy controls. Spot urine of 18 AD patients (AD group) and 18 age- and sex-matched, cognitively normal controls (control group) were analyzed by mass spectrometry (MS). Capillary electrophoresis time-of-flight MS and liquid chromatography-Fourier transform MS were used to cover a larger range of molecules with ionic as well as lipid characteristics. A total of 304 ionic molecules and 81 lipid compounds of 12 lipid classes were identified. Of these, 26 molecules showed significantly different relative concentrations between the AD and control groups (Wilcoxon's rank-sum test). Moreover, orthogonal partial least-squares discriminant analysis revealed significant discrimination between the two groups. Pathway searches using the KEGG database, and pathway enrichment and topology analysis using Metaboanalyst software, suggested alterations in molecules relevant to pathways of glycerolipid and glycerophospholipid metabolism, thermogenesis, and caffeine metabolism in AD patients. Further studies of urinary metabolites will contribute to the early detection of AD and understanding of its pathogenesis.

DOI： 10.3389/fneur.2021.719159

Variations in the estimated intake of acrylamide from food in the Japanese population Reviewed

Kumiko Kito, Junko Ishihara, Junpei Yamamoto, Takayuki Hosoda, Ayaka Kotemori, Ribeka Takachi, Kazutoshi Nakamura, Junta Tanaka, Taiki Yamaji, Taichi Shimazu, Yuri Ishii, Norie Sawada, Motoki Iwasaki, Hiroyasu Iso, Tomotaka Sobue, Shoichiro Tsugane

Nutrition Journal 19 ( 1 ) 2020.12

地域在住高齢者の認知機能低下予防プログラムの開発

北村香織, 佐藤久美, 林直美, 渡邊裕美, 中村和利

木村看護教育振興財団看護研究集録 ( 27 ) 36 - 60 2020.11

Language：Japanese Publisher：(公財)木村看護教育振興財団

地域高齢者の認知機能低下に関わる要因を明らかにするため、小千谷市の3地区に在住する高齢者で要支援・要介護認定を受けていない592名に面接調査を行い、その結果をもとに、科学的根拠に基づく認知機能低下予防プログラムを開発した。同プログラムを用いて認知機能低下予防教室を開催し、そのさい教育媒体として「生活習慣チェック用紙」を使用するとともに、面談時に「K10調査票」を用いてストレスの評価を行うこととした。さらに、教室終了後に面談結果をスタッフ間で検討することでハイリスク者を抽出し、個別支援を継続的に実施することとした。

Urinary Apolipoprotein C3 Is a Potential Biomarker for Alzheimer’s Disease

Yumi Watanabe, Yoshitoshi Hirao, Kensaku Kasuga, Takayoshi Tokutake, Kaori Kitamura, Shumpei Niida, Takeshi Ikeuchi, Kazutoshi Nakamura, Tadashi Yamamoto

Dementia and Geriatric Cognitive Disorders Extra 10 ( 3 ) 94 - 104 2020.9

Publishing type：Research paper (scientific journal) Publisher：S. Karger AG

<b><i>Introduction:</i></b> Biomarkers of Alzheimer’s disease (AD) that can easily be measured in routine health checkups are desirable. Urine is a source of biomarkers that can be collected easily and noninvasively. We previously reported on the comprehensive profile of the urinary proteome of AD patients and identified proteins estimated to be significantly increased or decreased in AD patients by a label-free quantification method. The present study aimed to validate urinary levels of proteins that significantly differed between AD and control samples from our proteomics study (i.e., apolipoprotein C3 [ApoC3], insulin-like growth factor-binding protein 3 [Igfbp3], and apolipoprotein D [ApoD]). <b><i>Methods:</i></b> Enzyme-linked immunosorbent assays (ELISAs) were performed using urine samples from the same patient and control groups analyzed in the previous proteomics study (18 AD and 18 controls, set 1) and urine samples from an independent group of AD patients and controls (13 AD, 5 mild cognitive impairment [MCI], and 32 controls) from the National Center for Geriatrics and Gerontology Biobank (set 2). <b><i>Results:</i></b> In set 1, the crude urinary levels of ApoD, Igfbp3, and creatinine-adjusted ApoD were significantly higher in the AD group relative to the control group (<i>p</i> = 0.003, <i>p</i> = 0.002, and <i>p</i> = 0.019, respectively), consistent with our previous proteomics results. In set 2, however, the crude urinary levels of Igfbp3 were significantly lower in the AD+MCI group than in the control group (<i>p</i> = 0.028), and the levels of ApoD and ApoC3 did not differ significantly compared to the control group. Combined analysis of all samples revealed creatinine-adjusted ApoC3 levels to be significantly higher in the AD+MCI group (<i>p</i> = 0.015) and the AD-only group (<i>p</i> = 0.011) relative to the control group. <b><i>Conclusion:</i></b> ApoC3 may be a potential biomarker for AD, as validated by ELISA. Further analysis of ApoC3 as a urinary biomarker for AD is warranted.

DOI： 10.1159/000509561

Predictors of decline in vitamin D status in middle-aged and elderly individuals: a 5-year follow-up study. Reviewed International journal

Kazutoshi Nakamura, Kaori Kitamura, Yumi Watanabe, Toshiko Saito, Akemi Takahashi, Ryosaku Kobayashi, Rieko Oshiki, Keiko Kabasawa, Ribeka Takachi, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Kei Watanabe

The British journal of nutrition 1 - 7 2020.5

Language：English Publishing type：Research paper (scientific journal)

Little is known about predictors of decline in vitamin D status (vitamin D decline) over time. We aimed to determine demographic and lifestyle variables associated with vitamin D decline by sufficiently controlling for seasonal effects of vitamin D uptake in a middle-aged to elderly population. Using a longitudinal study design within the larger framework of the Murakami Cohort Study, we examined 1044 individuals aged between 40 and 74 years, who provided blood samples at baseline and at 5-year follow-up, the latter of which were taken on a date near the baseline examination (±14 d). Blood 25-hydroxyvitamin D (25(OH)D) concentrations were determined with the Liaison® 25OH Vitamin D Total Assay. A self-administered questionnaire collected demographic, body size and lifestyle information. Vitamin D decline was defined as the lowest tertile of 5-year changes in blood 25(OH)D (Δ25(OH)D) concentration (<6·7 nmol/l). Proportions of those with vitamin D decline were 182/438 (41·6 %) in men and 166/606 (27·4 %) in women (P < 0·0001). In men, risk of vitamin D decline was significantly lower in those with an outdoor occupation (P = 0·0099) and those with the highest quartile of metabolic equivalent score (OR 0·34; 95 % CI 0·14, 0·83), and higher in those with 'university or higher' levels of education (OR 2·92; 95 % CI 1·04, 8·19). In women, risk of vitamin D decline tended to be lower with higher levels of vitamin D intake (Pfor trend = 0·0651) and green tea consumption (Pfor trend = 0·0025). Predictors of vitamin D decline differ by sex, suggesting that a sex-dependent intervention may help to maintain long-term vitamin D levels.

DOI： 10.1017/S0007114520001580

Dietary calcium and vitamin K are associated with osteoporotic fracture risk in middle-aged and elderly Japanese women, but not men: the Murakami Cohort Study. Reviewed International journal

Kseniia Platonova, Kaori Kitamura, Yumi Watanabe, Ribeka Takachi, Toshiko Saito, Keiko Kabasawa, Akemi Takahashi, Ryosaku Kobayashi, Rieko Oshiki, Aleksandr Solovev, Masayuki Iki, Shoichiro Tsugane, Ayako Sasaki, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

The British journal of nutrition 1 - 25 2020.5

Language：English Publishing type：Research paper (scientific journal)

Although dietary calcium, vitamin D, and vitamin K are nutritional factors associated with osteoporosis, little is known about their effects on incident osteoporotic fractures in East Asian populations. This study aimed to determine whether intakes of these nutrients predict incident osteoporotic fractures. We adopted a cohort-study design with a 5-year follow-up. Subjects were 12,794 community-dwelling individuals (6,301 men and 6,493 women) aged 40-74 years. Dietary intakes of calcium, vitamin D, and vitamin K were assessed with a validated food frequency questionnaire. Covariates were demographic and lifestyle factors. All incident cases of major osteoporotic limb fractures, including those of the distal forearm, neck of humerus, neck or trochanter of femur, and lumbar or thoracic spine were collected. Hazard ratios (HRs) for energy-adjusted calcium, vitamin D, and vitamin K were calculated with the residual method. Mean age was 58.8 years (SD=9.3). Lower energy-adjusted intakes of calcium and vitamin K in women were associated with higher adjusted HRs of total fractures (P for trend=0.005 and 0.08, respectively). When vertebral fracture was the outcome, P for trend values for calcium and vitamin K were 0.03 and 0.006, respectively, and HRs of the lowest and highest (reference) intake groups were 2.03 (95%CI:1.08-3.82) and 2.26 (95%CI:1.19-4.26), respectively. In men, there were null associations between incident fractures and each of the three nutrient intakes. Lower intakes of dietary calcium and vitamin K were independent, lifestyle-related risk factors for osteoporotic fracture in women but not men. These associations were robust for vertebral fractures, but not for limb fractures.

DOI： 10.1017/S0007114520001567

Study Design and Baseline Profiles of Participants in the Uonuma CKD Cohort Study in Niigata, Japan Reviewed

Keiko Kabasawa, Junta Tanaka, Kazutoshi Nakamura, Yumi Ito, Kinya Yoshida, Ribeka Takachi, Norie Sawada, Shoichiro Tsugane, Ichiei Narita

Journal of Epidemiology 30 ( 4 ) 170 - 176 2020.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Japan Epidemiological Association

BACKGROUND: Evidence for primary prevention of chronic kidney disease (CKD) is insufficient. The population-based prospective Uonuma CKD cohort study aims to explore associations of lifestyle and other risk factors with CKD. We report here the study design and baseline profiles. METHODS: All 67,322 residents aged ≥40 years in Minamiuonuma City, Uonuma City, and Yuzawa Town, Niigata Prefecture, Japan and 11,406 participants who attended local health-check examinations were targeted for baseline questionnaire and biochemical sampling, respectively. Information was gathered from 43,217 (64.2%) questionnaires and 8,052 (70.6%) biochemical samples; 6,945 participants consented to both questionnaire and biochemical sampling at baseline, conducted between fiscal years 2012 and 2015. Participants provided information regarding sociodemographic, lifestyle, and self-reported outcomes. Urine albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were measured. The primary outcome is CKD based on self-report and biochemical/clinical diagnosis. RESULTS: Mean age of questionnaire respondents was 63.3 (standard deviation [SD], 12.5) years for men and 64.3 (SD, 13.3) years for women. Among participants who submitted urine samples, median ACR was 10.0 (interquartile range [IQR], 5.0-24.0) mg/g for men and 13.0 (IQR, 7.7-27.0) mg/g for women, and median eGFR was 73.6 mL/min/1.73 m2 (IQR, 63.5-84.5) for men and 73.5 mL/min/1.73 m2 (IQR, 64.4-83.5) for women. ACR 30 mg/g or more was found in 1,741 participants (21.7%) and eGFR <60 mL/min/1.73 m2 in 1,361 participants (16.9%). CONCLUSION: The Uonuma CKD cohort study was established to investigate the impact of lifestyle on CKD development and to provide data for preventing the onset and progression of CKD.

DOI： 10.2188/jea.je20180220

Total physical activity and risk of chronic low back and knee pain in middle-aged and elderly Japanese people: The Murakami cohort study. Reviewed International journal

Aleksandr Solovev, Yumi Watanabe, Kaori Kitamura, Akemi Takahashi, Ryosaku Kobayashi, Toshiko Saito, Ribeka Takachi, Keiko Kabasawa, Rieko Oshiki, Kseniia Platonova, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Osamu Yamazaki, Kei Watanabe, Kazutoshi Nakamura

European journal of pain (London, England) 24 ( 4 ) 863 - 872 2020.4

Language：English

BACKGROUND: Specific components of physical activity, such as vigorous exercise and heavy occupational work, are known to increase the risk of chronic low back pain (CLBP) and chronic knee pain (CKP), but impacts of other components are less known. This study aimed to assess the relationship between total physical activity and risk of CLBP and CKP from a public health perspective. METHODS: Participants were 7,565 individuals, aged 40-74 years, who did not have CLBP or CKP, and who participated in the 5-year follow-up survey. A self-administered questionnaire was used to obtain information on demographics, body size and lifestyle (including physical activity) in the baseline survey in 2011-2013, and on CLBP and CKP using Short Form 36 (SF-36) in the follow-up survey. Sitting, standing, walking and strenuous work for occupational activity were assessed for total physical activity, and walking slowly, walking quickly, light to moderate exercise and strenuous exercise were assessed for leisure-time physical activity using metabolic equivalent hours/day (METs score). RESULTS: Mean age of participants was 60.1 years (SD, 8.8). Participants with higher METs scores had a significantly higher risk of CKP (p for trend = 0.0089, OR of 4th quartile = 1.29, 95% CI: 1.04-1.59 vs. 1st quartile), but not CLBP. An intermediate leisure-time METs score was associated with a lower risk of CLBP (OR = 0.75, 95%CI: 0.61-0.92 vs. 0 METs-group). CONCLUSIONS: A high level of total physical activity may increase the risk of CKP, whereas an intermediate level of leisure-time physical activity may decrease the risk of CLBP, in middle-aged and elderly individuals. SIGNIFICANCE: Evidence on the longitudinal association between total physical activity and CLBP and CKP in middle-aged and elderly people is lacking. We conducted a cohort study to assess this association, and found that high levels of total physical activity increased risk of CKP, and intermediate levels of leisure-time physical activity decreased risk of CLBP. This suggests that the effect of physical activity on chronic pain differed by pain site.

DOI： 10.1002/ejp.1535

Psychological distress as a risk factor for dementia after the 2004 Niigata-Chuetsu earthquake in Japan. Reviewed International journal

Kazutoshi Nakamura, Yumi Watanabe, Kaori Kitamura, Keiko Kabasawa, Toshiyuki Someya

Journal of affective disorders 259 121 - 127 2019.12

Language：English

BACKGROUND: A large earthquake can cause extreme stress and may adversely affect cognitive function in humans. We aimed to examine a possible association between psychological distress and incident dementia after the 2004 Niigata-Chuetsu earthquake in Japan. METHODS: This is a retrospective cohort study followed participants for 10-12 years. Subjects were 6,012 residents in 2005, 5,424 in 2006, and 5,687 in 2007 (age ≥40 years) living in Ojiya city who participated in the annual health check examinations after the 2004 Niigata-Chuetsu earthquake. Psychological distress was assessed using the Kessler Psychological Distress Scale (K10), and individuals with a K10 score ≥10 were considered to have psychological distress. Incident dementia cases were identified from a long-term care insurance database of the local government during the follow-up period. We evaluated hazard ratios (HRs) of psychological distress for incident dementia in each year, unadjusted and adjusted for covariates, including sex, age, occupation, BMI, and property damage of residential area. RESULTS: The average age of the subjects was 64.6 years in 2005, 64.6 in 2006, and 65.2 in 2007. Adjusted HRs were significantly higher (HR = 1.20-1.66) in the psychological distress group than in the reference group in each year. In particular, adjusted HR was high (HR = 2.89) in those with psychological distress in all three years (2005-2007). CONCLUSION: Psychological distress, especially persistent distress, is a risk factor for incident dementia in victims of large disasters.

DOI： 10.1016/j.jad.2019.08.041

Association of estimated dietary acid load with albuminuria in Japanese adults: a cross-sectional study Reviewed International journal

Keiko Kabasawa, Michihiro Hosojima, Ribeka Takachi, Kazutoshi Nakamura, Yumi Ito, Akihiko Saito, Norie Sawada, Shoichiro Tsugane, Junta Tanaka, Ichiei Narita

BMC Nephrology 20 ( 1 ) 194 - 194 2019.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

BACKGROUND: Acid-base imbalance might promote the progression of chronic kidney disease (CKD), but whether nutrient-derived dietary acid load increases the risk of albuminuria or even high normoalbuminuria is unclear. METHODS: A Japanese cohort comprising 3250 men and 3434 women aged 40-97 years with urine albumin-to-creatinine ratio (ACR) < 33.9 mg/mmol or estimated glomerular filtration rate ≥ 15 ml/min/1.73 m2 were assessed. We performed a cross-sectional evaluation of the association between net endogenous acid production (NEAP), estimated as dietary protein to potassium content ratio, and the presence of high normoalbuminuria (ACR: 1.13-3.38 mg/mmol) or microalbuminuria. RESULTS: Median NEAP was 43.4 (interquartile range (IQR): 34.2-53.4) mEq/day in men and 35.0 (IQR: 27.7-43.6) mEq/day in women. Median ACR was 1.11 (IQR: 0.57-2.49) mg/mmol in men and 1.47 (IQR: 0.82-2.83) mg/mmol in women. In multivariate analysis, the adjusted odds ratio of the highest versus lowest NEAP quartile for microalbuminuria was 1.47 (95% confidence interval (CI): 1.08-1.99) in men and 1.54 (95% CI: 1.11-2.14) in women. For high normoalbuminuria or microalbuminuria, the adjusted odds ratio was 1.28 (95% CI: 1.02-1.59) in men and 1.39 (95% CI: 1.11-1.74) in women. From nutrient composition analysis, subjects with the highest potassium intake, but not protein intake, had lower adjusted odds ratios for the presence of microalbuminuria than those in the lowest quartile for potassium intake. CONCLUSIONS: Higher NEAP was associated with albuminuria and its association might negatively relate to potassium intake in an adult Japanese population.

DOI： 10.1186/s12882-019-1352-8

Other Link： http://link.springer.com/article/10.1186/s12882-019-1352-8/fulltext.html

Modifiable factors associated with symptomatic knee osteoarthritis: The Murakami cohort study. Reviewed International journal

Ryoya Takiguchi, Rintaro Komatsu, Kaori Kitamura, Yumi Watanabe, Akemi Takahashi, Ryosaku Kobayashi, Rieko Oshiki, Toshiko Saito, Keiko Kabasawa, Ribeka Takachi, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Osamu Yamazaki, Kazutoshi Nakamura

Maturitas 128 53 - 59 2019.10

Language：English

OBJECTIVES: Modifiable risk factors for knee osteoarthritis (OA) have not been studied in detail. This study aimed to determine lifestyle-related modifiable factors of symptomatic knee osteoarthritis in an East Asian population. STUDY DESIGN: This 5-year cohort study involved 11,091 individuals (age range 40-72 years) living in the Murakami region of Niigata, Japan, who did not have a history of knee OA. At baseline, information on sociodemographic characteristics, body size, lifestyle, and living condition was obtained using a self-administered questionnaire. MAIN OUTCOME MEASURES: Incident symptomatic knee OA observed at hospitals and orthopaedic clinics in the five years to 2016. Clinical grades of knee OA were based on the Kellgren-Lawrence scale. P for trend was assessed to examine linear associations between predictors and the outcome in multiple logistic regression analysis. RESULTS: The mean age of participants was 58.1 (SD 9.3) years. The number of cases of grade 2 or more incident knee OA was 429. In men, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), higher METs score (P for trend = 0.0150), less smoking (P for trend = 0.0249), and lower green tea consumption (P for trend = 0.0437) were associated with incident knee OA. In women, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), and alcohol consumption (P = 0.0153) were associated with incident knee OA. CONCLUSIONS: Several lifestyle-related factors were found to be associated with incident knee OA and exhibited sex-dependent differences. In particular, higher consumption of green tea was associated with a lower incidence of knee OA in men.

DOI： 10.1016/j.maturitas.2019.06.013

Low serum 25-hydroxyvitamin D is associated with low grip strength in an older Japanese population. Reviewed

Kitsu T, Kabasawa K, Ito Y, Kitamura K, Watanabe Y, Tanaka J, Nakamura K, Narita I

Journal of bone and mineral metabolism 2019.8

Physical activity modifies the effect of calcium supplements on bone loss in perimenopausal and postmenopausal women: subgroup analysis of a randomized controlled trial. Reviewed

Nakamura K, Saito T, Kobayashi R, Oshiki R, Kitamura K, Watanabe Y

Archives of osteoporosis 14 ( 1 ) 17 2019.2

Molecular Network Analysis of the Urinary Proteome of Alzheimer's Disease Patients. Reviewed

Watanabe Y, Hirao Y, Kasuga K, Tokutake T, Semizu Y, Kitamura K, Ikeuchi T, Nakamura K, Yamamoto T

Dementia and geriatric cognitive disorders extra 9 ( 1 ) 53 - 65 2019.1

Food frequency questionnaire reproducibility for middle-aged and elderly Japanese. Reviewed International journal

Koutatsu Maruyama, Ai Ikeda, Junko Ishihara, Ribeka Takachi, Norie Sawada, Taichi Shimazu, Kazutoshi Nakamura, Junta Tanaka, Taiki Yamaji, Motoki Iwasaki, Hiroyasu Iso, Shoichiro Tsugane

Asia Pacific journal of clinical nutrition 28 ( 2 ) 362 - 370 2019

Language：English

BACKGROUND AND OBJECTIVES: The aim of this study was to examine the reproducibility of a self-administered food frequency questionnaire (FFQ) originally developed for the Japan Public Health Center-Based Prospective Study (JPHC study) and modified for use in the Next Generation (JPHC-NEXT) study. METHODS AND STUDY DESIGN: Participants included 98 men and 142 women aged 40-74 years from the five areas included in the JPHCNEXT protocol. In November 2012, participants were recruited and asked to complete the first nutrition survey. The second nutrition survey was completed after 1 year. RESULTS: We estimated daily energy as well as 53 nutrient and 29 food group intakes using the FFQ. To assess reproducibility, we calculated Spearman correlation coefficients between both FFQs, which showed mostly intermediate-to-high values. Median (range) correlation coefficients and quartile distribution in the same and adjacent categories for energy-adjusted nutrient intakes were 0.55 (0.42-0.84) and 84.7% (76.5%-98.0%) in men and 0.54 (0.35-0.80) and 84.5% (76.1%-94.4%) in women. The respective values for energy-adjusted food group intakes in men and women were also mostly intermediate to high: 0.54 (0.39-0.79) and 83.7% (75.5%-90.8%) in men and 0.57 (0.40-0.83) and 84.5% (77.5%-93.7%) in women. CONCLUSIONS: The FFQ developed for the JPHC-NEXT study has reasonable reproducibility. Because this FFQ has also been validated in a previous study, it can be considered a useful dietary assessment tool to examine associations between dietary consumption and lifestyle-related diseases.

DOI： 10.6133/apjcn.201906_28(2).0019

Menstrual and reproductive factors and risk of vertebral fractures in Japanese women: the Japan Public Health Center-based prospective (JPHC) study. Reviewed

Shimizu Y, Sawada N, Nakamura K, Watanabe Y, Kitamura K, Iwasaki M, Tsugane S, JPHC Study group

Osteoporos Int 2018.8

The Murakami Cohort Study of vitamin D for the prevention of musculoskeletal and other age-related diseases: A study protocol Reviewed

Kazutoshi Nakamura, Ribeka Takachi, Kaori Kitamura, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Yumi Watanabe, Keiko Kabasawa, Akemi Takahashi, Shoichiro Tsugane, Masayuki Iki, Ayako Sasaki, Osamu Yamazaki

Environmental Health and Preventive Medicine 23 ( 1 ) 28 2018.6

Language：English Publishing type：Research paper (scientific journal) Publisher：BioMed Central Ltd.

Background: Age-related musculoskeletal diseases are becoming increasingly burdensome in terms of both individual quality of life and medical cost. We intended to establish a large population-based cohort study to determine environmental, lifestyle, and genetic risk factors of musculoskeletal and other age-related diseases, and to clarify the association between vitamin D status and such diseases. Methods: We targeted 34,802 residents aged 40-74 years living in areas of northern Niigata Prefecture, including Sekikawa Village, Awashimaura Village, and Murakami City (Murakami region). The baseline questionnaire survey, conducted between 2011 and 2013, queried respondents on their lifestyle and environmental factors (predictors), and self-reported outcomes. Plasma 25-hydroxyvitamin D (25[OH]D) concentration, an indicator of vitamin D status, was determined with the Liaison® 25OH Vitamin D Total Assay. The primary outcome of this study was osteoporotic fracture
other outcomes included age-related diseases including knee osteoarthritis, perception of chronic pain, dementia, and long-term care insurance use. Mean ages of men and women were 59.2 (SD = 9.3, N = 6907) and 59.0 (SD = 9.3, N = 7457) years, respectively. From the blood samples provided by 3710 men and 4787 women, mean 25(OH)D concentrations were 56.5 (SD = 18.4) nmol/L (22.6 ng/mL) and 45.4 (SD = 16.5) nmol/L (18.2 ng/mL), respectively. Discussion: Follow-up surveys are planned every 5 years for 15 years, and incident cases of our targeted diseases will be followed at hospitals and clinics in and nearby the cohort area. We anticipate that we will be able to clarify the association between vitamin D status and multiple disease outcomes in a Japanese population.

DOI： 10.1186/s12199-018-0715-2

Low serum 25-hydroxyvitamin D increases cognitive impairment in elderly people. Reviewed

Sakuma M, Kitamura K, Endo N, Ikeuchi T, Yokoseki A, Onodera O, Oinuma T, Momotsu T, Sato K, Nakamura K, Narita I

Journal of bone and mineral metabolism 2018.6

Association of liver enzyme levels and alveolar bone loss: A cross-sectional clinical study in Sado Island. Reviewed International journal

Ayumi Kuroki, Noriko Sugita, Shigeki Komatsu, Akio Yokoseki, Akihiro Yoshihara, Tetsuo Kobayashi, Kazutoshi Nakamura, Takeshi Momotsu, Naoto Endo, Kenji Sato, Ichiei Narita, Hiromasa Yoshie

Journal of clinical and experimental dentistry 10 ( 2 ) e100-e106 - e106 2018.2

Language：English Publishing type：Research paper (scientific journal)

Background: The interaction of periodontopathic bacteria with host immune system induces the production of inflammatory mediators which leads to alveolar bone loss (ABL), the essential feature of periodontitis. Concurrently, periodontal diseases cause the elevation of blood cytokine levels, the alteration of gut microbiota and the dissemination of enterobacteria to the liver. Owing to these mechanisms, periodontal disease might be a risk for liver dysfunction. Several epidemiological studies have reported associations between periodontal diseases and liver dysfunction, although the association between ABL and liver dysfunction has not been investigated. This cross-sectional study determined if elevated serum liver enzyme levels were associated with ABL in Japanese adults. Material and Methods: Japanese adults living on Sado Island who visited Sado General Hospital were invited to participate in the study. Participants over 40 years of age who underwent dental panoramic radiography and blood tests were included. Drinking and smoking habits were self-administered. After excluding patients with edentulous jaw, diagnosed liver diseases, and those on dialysis, data from 44 men and 66 women with a mean age of 73 years were analyzed. The average percentage of ABL for each participant was calculated for mesial and distal sites of all remaining teeth. The levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) were determined. Univariate analyses were performed to select covariates to be put in multivariate analyses. The association between elevated serum liver enzyme levels and the highest quartile of ABL were assessed by multiple logistic regression analysis. Results: After adjusting for covariates, no significant association was found between elevated serum AST, ALT, or GGT levels as dependent variables and the highest quartile of ABL as an explanatory variable. Conclusions: There was no significant association between the elevation of serum liver enzyme levels and ABL in Japanese adults. Key words:Liver enzymes, dental panoramic radiography, alveolar bone loss, Japanese adults.

DOI： 10.4317/jced.54555

Effect of monitoring salt concentration of home-prepared dishes and using low-sodium seasonings on sodium intake reduction. Reviewed

Nakadate M, Ishihara J, Iwasaki M, Kitamura K, Kato E, Tanaka J, Nakamura K, Ishihara T, Shintani A, Takachi R

European journal of clinical nutrition 72 ( 10 ) 1413 - 1420 2018.1

Epidemiological profiles of chronic low back and knee pain in middle-aged and elderly Japanese from the Murakami cohort. Reviewed

Takahashi A, Kitamura K, Watanabe Y, Kobayashi R, Saito T, Takachi R, Kabasawa K, Oshiki R, Tsugane S, Iki M, Sasaki A, Yamazaki O, Nakamura K

Journal of pain research 11 3161 - 3169 2018

Association between dialysis treatment and cognitive decline: A study from the Project in Sado for Total Health (PROST), Japan Reviewed

Yumi Watanabe, Kaori Kitamura, Kazutoshi Nakamura, Kazuhiro Sanpei, Minako Wakasugi, Akio Yokoseki, Keiko Kabasawa, Osamu Onodera, Takeshi Ikeuchi, Ryozo Kuwano, Takeshi Momotsu, Ichici Narita, Naoto Endo

GERIATRICS & GERONTOLOGY INTERNATIONAL 17 ( 10 ) 1584 - 1587 2017.10

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Aim: Evidence for the association between dialysis treatment and cognitive decline is limited. The present study aimed to determine whether dialysis treatment is associated with cognitive decline in adult outpatients of a general hospital in Japan.
Methods: This was a cross-sectional substudy of the Project in Sado for Total Etealth (PROST). Total Etealth PROST targeted adult outpatients of a general hospital in Sado City, Niigata, Japan. Among 753 patients (mean age 68.1 11.6 years) analyzed, 66 received dialysis. Cognitive state was evaluated using the Mini-Mental State Examination, and those with a Mini-Mental State Examination score <24 were considered "cognitively declined." The prevalence of cognitive decline was compared by odds ratios calculated with multiple logistic regression analysis. Variables included in the analyses were dialysis, age, sex and self-reported histories of hypertension, diabetes, stroke and ischemic heart disease.
Results: Of the 66 dialysis patients, 24 (36.4%) showed cognitive decline, whereas 172 (25.0%) of 687 non-dialysis patients showed cognitive decline. The age and sex-adjusted odds ratio for cognitive decline in dialysis patients was 2.57 (95% confidence interval 1.43-4.61), relative to non-dialysis patients. The odds ratio remained significant (odds ratio 2.69, 95% confidence interval 1.49-4.88) even after adjusting for all covariates.
Conclusion: The prevalence of cognitive decline was high in dialysis patients relative to non-dialysis patients among outpatients of a general hospital in Japan..

DOI： 10.1111/ggi.129.7

Weight loss from 20 years of age is associated with cognitive impairment in middle-aged and elderly individuals Reviewed

Kaori Kitamura, Yumi Watanabe, Kazutoshi Nakamura, Akemi Takahashi, Ribeka Takachi, Rieko Oshiki, Ryosaku Kobayashi, Toshiko Saito, Shoichiro Tsugane, Ayako Sasaki

PLOS ONE 12 ( 10 ) e0185960 2017.10

Language：English Publishing type：Research paper (scientific journal) Publisher：PUBLIC LIBRARY SCIENCE

Background
Few empirical studies have been conducted to identify modifiable factors that may affect cognitive impairment in Japanese individuals. The present study aimed to clarify whether body mass and lifestyle are associated with cognitive impairment in Japanese middle-aged and elderly individuals.
Methods
Subjects were 1814 community-dwelling individuals aged 44-79 years, all of whom were participants of the Murakami Cohort Study baseline survey conducted in 2011-2013. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) in 2014-2016, and cognitive impairment, the outcome measure, was defined as an MMSE score <24. Predictor variables were body mass index (BMI), long-term weight changes from 20 years of age, and lifestyle factors, such as smoking, drinking, and physical activity levels, which were obtained from a self-administered questionnaire in the baseline survey. Covariates were sex, age, education level, and histories of stroke and diabetes. Multiple logistic regression analysis was used to calculate the adjusted odds ratios (ORs).
Results
The prevalence of overall cognitive impairment was 6.2%. The adjusted ORs of cognitive impairment in the lowest (<[-4] kg) (OR = 2.70, 95% CI, 1.18-6.20) and second ([-4]-[0] kg) (OR = 2.37, 95% CI, 1.04-5.37) quintiles for long-term weight change were significantly higher than the reference 4th quintile ([+4]-[+7] kg). The adjusted OR in the highest quintile >=[+8] kg) was 2.24 (95% CI, 0.99-5.04). Current BMI was not associated with cognitive impairment.
Conclusions
Long-term weight loss is associated with cognitive impairment in Japanese middle-aged and elderly individuals. Because the present study was retrospective in nature, prospective studies should also be conducted for further characterization of this association.

DOI： 10.1371/journal.pone.0185960

Online version of the self-administered food frequency questionnaire for the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT) protocol: Relative validity, usability, and comparison with a printed questionnaire Reviewed

Erika Kato, Ribeka Takachi, Junko Ishihara, Yuri Ishii, Shizuka Sasazuki, Norie Sawada, Motoki Iwasaki, Yurie Shinozawa, Jun Umezawa, Junta Tanaka, Yuta Yokoyama, Kaori Kitamura, Kazutoshi Nakamura, Shoichiro Tsugane

JOURNAL OF EPIDEMIOLOGY 27 ( 9 ) 435 - 446 2017.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

Background: Online dietary assessment tools offer advantages over printed questionnaires, such as the automatic and direct data storage of answers, and have the potential to become valuable research methods. We developed an online survey system (web-FFQ) for the existing printed FFQ used in the JPHC-NEXT protocol, the platform of a large-scale genetic cohort study. Here, we examined the validity of ranking individuals according to dietary intake using this web-FFQ and its usability compared with the printed questionnaire (print-FFQ) for combined usage.
Methods: We included 237 men and women aged 40-74 years from five areas specified in the JPHCNEXT protocol. From 2012 to 2013, participants were asked to provide 12-day weighed food records (12d-WFR) as the reference intake and to respond to the print-and web-FFQs. Spearman's correlation coefficients (CCs) between estimates using the web-FFQ and 12d-WFR were calculated. Crossclassification of intakes was compared with those using the print-FFQ.
Results: Most participants (83%) answered that completing the web-FFQ was comparable to or easier than completing the printed questionnaire. The median value of CCs across energy and 53 nutrients for men and women was 0.47 (range, 0.10-0.86) and 0.46 (range, 0.16-0.69), respectively. CCs for individual nutrient intakes were closely similar to those based on the print-FFQ, irrespective of response location. Cross-classification by quintile of intake based on two FFQs was reasonably accurate for many nutrients and food groups.
Conclusion: This online survey system is a reasonably valid measure for ranking individuals by intake for many nutrients, like the printed FFQ. Mixing of two FFQs for exposure assessments in epidemiological studies appears acceptable. (C) 2017 Publishing services by Elsevier B.V. on behalf of The Japan Epidemiological Association.

DOI： 10.1016/j.je.2016.08.021

Comparison of weighed food record procedures for the reference methods in two validation studies of food frequency questionnaires Reviewed

Yuri Ishii, Junko Ishihara, Ribeka Takachi, Yurie Shinozawa, Nahomi Imaeda, Chiho Goto, Kenji Wakai, Toshiaki Takahashi, Hiroyasu Iso, Kazutoshi Nakamura, Junta Tanaka, Taichi Shimazu, Taiki Yamaji, Shizuka Sasazuki, Norie Sawada, Motoki Iwasaki, Haruo Mikami, Kiyonori Kuriki, Mariko Naito, Naoko Okamoto, Fumi Kondo, Satoyo Hosono, Naoko Miyagawa, Etsuko Ozaki, Sakurako Katsuura-Kamano, Keizo Ohnaka, Hinako Nanri, Noriko Tsunematsu-Nakahata, Takamasa Kayama, Ayako Kurihara, Shiomi Kojima, Hideo Tanaka, Shoichiro Tsugane

JOURNAL OF EPIDEMIOLOGY 27 ( 7 ) 331 - 337 2017.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

Background: Although open-ended dietary assessment methods, such as weighed food records (WFRs), are generally considered to be comparable, differences between procedures may influence outcome when WFRs are conducted independently. In this paper, we assess the procedures of WFRs in two studies to describe their dietary assessment procedures and compare the subsequent outcomes.
Methods: WFRs of 12 days (3 days for four seasons) were conducted as reference methods for intake data, in accordance with the study protocol, among a subsample of participants of two large cohort studies. We compared the WFR procedures descriptively. We also compared some dietary intake variables, such as the frequency of foods and dishes and contributing foods, to determine whether there were differences in the portion size distribution and intra-and inter-individual variation in nutrient intakes caused by the difference in procedures.
Results: General procedures of the dietary records were conducted in accordance with the National Health and Nutrition Survey and were the same for both studies. Differences were seen in 1) selection of multiple days (non-consecutive days versus consecutive days); and 2) survey sheet recording method (individual versus family participation). However, the foods contributing to intake of energy and selected nutrients, the portion size distribution, and intra-and inter-individual variation in nutrient intakes were similar between the two studies.
Conclusion: Our comparison of WFR procedures in two independent studies revealed several differences. Notwithstanding these procedural differences, however, the subsequent outcomes were similar. (C) 2017 The Authors. Publishing services by Elsevier B.V. on behalf of The Japan Epidemiological Association.

DOI： 10.1016/j.je.2016.08.008

Rural-urban differences in the prevalence of cognitive impairment in independent community-dwelling elderly residents of Ojiya city, Niigata Prefecture, Japan Reviewed

Kazutoshi Nakamura, Kaori Kitamura, Yumi Watanabe, Hiroko Shinoda, Hisami Sato, Toshiyuki Someya

ENVIRONMENTAL HEALTH AND PREVENTIVE MEDICINE 21 ( 6 ) 422 - 429 2016.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

This study aimed to examine rural-urban differences in the prevalence of cognitive impairment in Japan.
We targeted 592 residents aged 65 years and older who did not use long-term care insurance services in one rural and two urban areas in Ojiya City, Japan. Of these, 537 (90.7 %) participated in the study. The revised Hasegawa's dementia scale (HDS-R) was used to assess cognitive function, and cognitive impairment was defined as a HDS-R score aecurrency sign20. Lifestyle information was obtained through interviews. The prevalence of cognitive impairment was compared according to the levels of predictor variables by odds ratios (ORs) calculated by a logistic regression analysis.
Mean age of participants was 75.7 years (SD 7.0). The prevalence of cognitive impairment was 20/239 (8.4 %) in the rural area and 6/298 (2.0 %) in the urban areas, for a total of 26/537 (4.8 %) overall. Men tended to have a higher prevalence of cognitive impairment (P = 0.0628), and age was associated with cognitive impairment (P for trend < 0.0001). The rural area had a significantly higher prevalence of cognitive impairment (age- and sex-adjusted OR = 4.04, 95 % CI: 1.54-10.62) than urban areas. This difference was significant after adjusting for other lifestyle factors.
The prevalence of cognitive impairment was higher in the rural area relative to urban areas in Ojiya city. This regional difference suggests the existence of potentially modifiable factors other than lifestyle in relation to cognitive impairment.

DOI： 10.1007/s12199-016-0542-2

Cognitive function is maintained in noninstitutionalized elderly Japanese requiring care with high levels of health-related quality of life Reviewed

Kaori Kitamura, Kazutoshi Nakamura, Kimiko Ueno, Tomoko Nishiwaki

ENVIRONMENTAL HEALTH AND PREVENTIVE MEDICINE 21 ( 6 ) 585 - 590 2016.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Health-related quality of life (HRQOL) has been reported to be associated with cognitive function; however, whether or not this relationship involves causality is uncertain. This study aimed to determine whether HRQOL levels are associated with subsequent changes in cognitive function in elderly people requiring care.
Participants were 74 community-dwelling elderly people utilizing the long-term care service (69 % women) who underwent physical and psychological examinations at baseline and follow-up. The outcome was 2-year changes in Mini-Mental State Examination (a dagger MMSE) score. The potential predictor was HRQOL level assessed by the EuroQol 5 dimension (EQ-5D) score (utility value) at baseline; other variables were body mass index (BMI), Barthel index, grip strength, Geriatric Depression Scale, serum albumin, and serum hemoglobin. Associations between EQ-5D and a dagger MMSE scores were assessed using correlation analysis, regression analysis, and analysis of covariance (ANCOVA).
Mean age, BMI, and Barthel index at baseline were 81.6 years [standard deviation (SD) 8.2], 21.1 kg/m(2) (SD 4.0), and 79 (SD 20), respectively; the mean a dagger MMSE score was -2.2 (SD 5.1). EQ-5D was significantly correlated with a dagger MMSE (partial r = 0.375, P = 0.0012). The mean a dagger MMSE values of the 1st, 2nd, and 3rd EQ-5D quartiles were -4.2 (adjusted P = 0.0050), -2.6 (adjusted P = 0.0476), and -2.4 (adjusted P = 0.0298), respectively, which were lower than the -0.1 of the reference 4th quartile.
HRQOL as assessed by EQ-5D is associated with longitudinal cognitive decline in frail elderly people, and cognitive function may be maintained in individuals with high HRQOL levels.

DOI： 10.1007/s12199-016-0572-9

Validity of Short and Long Self-Administered Food Frequency Questionnaires in Ranking Dietary Intake in Middle-Aged and Elderly Japanese in the Japan Public Health Center-Based Prospective Study for the Next Generation (JPHC-NEXT) Protocol Area Reviewed

Yuta Yokoyama, Ribeka Takachi, Junko Ishihara, Yuri Ishii, Shizuka Sasazuki, Norie Sawada, Yurie Shinozawa, Junta Tanaka, Erika Kato, Kaori Kitamura, Kazutoshi Nakamura, Shoichiro Tsugane

JOURNAL OF EPIDEMIOLOGY 26 ( 8 ) 420 - 432 2016.8

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN EPIDEMIOLOGICAL ASSOC

Background: Longitudinal epidemiological studies require both the periodic update of intake information via repeated dietary survey and the minimization of subject burden in responding to questionnaires. We developed a 66-item Food Frequency Questionnaire (short-FFQ) for the Japan Public Health Center-based prospective Study for the Next Generation (JPHC-NEXT) follow-up survey using major foods from the FFQ developed for the original JPHC Study. For the JPHC-NEXT baseline survey, we used a larger 172-item FFQ (long-FFQ), which was also derived from the JPHC-FFQ. We compared the validity of ranking individuals by levels of dietary consumption by these FFQs among residents of selected JPHC-NEXT study areas.
Methods: From 2012 to 2013, 240 men and women aged 40-74 years from five areas in the JPHC-NEXT protocol were asked to respond to the long-FFQ and provide 12-day weighed food records (WFR) as reference; 228 also completed the short-FFQ. Spearman's correlation coefficients (CCs) between estimates from the FFQs and WFR were calculated and corrected for intra-individual variation of the WFR.
Results: Median CC values for energy and 53 nutrients for the short-FFQ for men and women were 0.46 and 0.44, respectively. Respective values for the long-FFQ were 0.50 and 0.43. Compared with the long-FFQ, cross-classification into exact plus adjacent quintiles with the short-FFQ ranged from 68% to 91% in men and 58% to 85% in women.
Conclusions: Similar to the long-FFQ, the short-FFQ provided reasonably valid measures for ranking middle-aged and elderly Japanese for many nutrients and food groups. The short-FFQ can be used in follow-up surveys in prospective cohort studies aimed at updating diet rank information.

DOI： 10.2188/jea.JE20150064

Association between Dietary Intake and Bone Mineral Density in Japanese Postmenopausal Women: The Yokogoshi Cohort Study Reviewed

Harumi Hirata, Kaori Kitamura, Toshiko Saito, Ryosaku Kobayashi, Masanori Iwasaki, Akihiro Yoshihara, Yumi Watanabe, Rieko Oshiki, Tomoko Nishiwaki, Kazutoshi Nakamura

TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 239 ( 2 ) 95 - 101 2016.6

Language：English Publishing type：Research paper (scientific journal) Publisher：TOHOKU UNIV MEDICAL PRESS

Diet and food intake play an important role in the development of osteoporosis. However, apart from calcium and vitamin D, how nutrients affect bone status is not fully understood. The purpose of this study was to determine cross-sectional and longitudinal associations between dietary intake and bone mineral density (BMD) in Japanese postmenopausal women. This 5-year cohort study included 600 community dwelling women aged 55-74 years at baseline in 2005. Information on demographics, nutrition, and lifestyle was obtained through interviews, and nutritional and dietary intake was assessed using a validated food frequency questionnaire. BMD measurements were performed by dual energy X-ray absorptiometry. In 2010, 498 women underwent follow-up BMD examinations. Multiple linear regression analysis was performed to determine associations of predictor variables with BMD, adjusting for confounders. In cross-sectional analyses, coffee or black tea consumption was positively associated with lumbar spine (P = 0.004) and total hip (P = 0.003) BMD, and alcohol intake was positively associated with femoral neck (P = 0.005) and total hip (P = 0.001) BMD. In longitudinal analyses, vitamin K (P = 0.028) and natto (fermented soybeans) (P = 0.023) were positively associated with lumbar spine BMD, and meat or meat product consumption was inversely associated with total hip (P = 0.047) BMD. In conclusion, dietary factors other than calcium and vitamin D intake are predictors of bone mass and bone loss in Japanese postmenopausal women. In particular, natto intake is recommended for preventing postmenopausal bone loss on the basis of current evidence.

DOI： 10.1620/tjem.239.95

【災害と自殺予防】新潟県中越地震被災地における住民の心の健康の推移

中村和利, 北村香織

自殺予防と危機介入 36 ( 2 ) 8 - 12 2016.3

Elevated C-Reactive Protein is Associated with Cognitive Decline in Outpatients of a General Hospital: The Project in Sado for Total Health (PROST) Reviewed

Yumi Watanabe, Kaori Kitamura, Kazutoshi Nakamura, Kazuhiro Sanpei, Minako Wakasugi, Akio Yokoseki, Osamu Onodera, Takeshi Ikeuchi, Ryozo Kuwano, Takeshi Momotsu, Ichiei Narita, Naoto Endo

Dementia and Geriatric Cognitive Disorders Extra 6 ( 1 ) 10 - 19 2016

Language：English Publishing type：Research paper (scientific journal) Publisher：S. Karger AG

Background/Aims: We aimed to determine whether the concentration of serum C-reactive protein (CRP) is associated with cognitive function in an adult Japanese population. Methods: Participants of this cross-sectional study were from a subgroup of the Project in Sado for Total Health (PROST
n = 454
mean age, 70.5 years). The cognitive state was evaluated using the Mini-Mental State Examination (MMSE), and those with an MMSE score &lt
24 were considered 'cognitively declined'. Concentrations of serum high-sensitivity CRP were measured. Multiple logistic regression analysis was used to calculate odds ratios (ORs) for cognitive decline, adjusting for the covariates of age, sex, BMI, disease history, and APOE allele. Results: Of the 454 participants, 94 (20.7%) were cognitively declined. Relative to the lowest (first) quartile of CRP concentration, adjusted ORs were 1.29 (95% CI 0.61-2.75) for the second, 1.78 (95% CI 0.82-3.86) for the third, and 3.05 (95% CI 1.45-6.42) for the highest (fourth) quartiles (p for trend = 0.018). When data were stratified by sex, the association between CRP concentration and cognitive decline was observed only in women. Conclusion: Our findings suggest an association between higher CRP concentration and lower cognitive function. Chronic inflammation may affect cognitive function in adults, in particular women.

DOI： 10.1159/000442585

Modifiable Factors Associated with Cognitive Impairment in 1,143 Japanese Outpatients: The Project in Sado for Total Health (PROST) Reviewed

Kaori Kitamura, Yumi Watanabe, Kazutoshi Nakamura, Kazuhiro Sanpei, Minako Wakasugi, Akio Yokoseki, Osamu Onodera, Takeshi Ikeuchi, Ryozo Kuwano, Takeshi Momotsu, Ichiei Narita, Naoto Endo

Dementia and Geriatric Cognitive Disorders Extra 6 ( 2 ) 341 - 349 2016

Language：English Publishing type：Research paper (scientific journal) Publisher：S. Karger AG

Background/Aims: Evidence on modifiable factors associated with cognitive impairment in Japanese patients is scarce. This study aimed to determine modifiable factors for cognitive impairment in a Japanese hospital-based population. Methods: Subjects of this cross-sectional study were 1,143 patients of Sado General Hospital (Niigata, Japan) registered in the Project in Sado for Total Health (PROST) between June 2008 and September 2014. We assessed disease history, body mass index (BMI), leisure time physical activity, walking time, smoking and drinking habits, and consumption of vegetables, fruits, and green tea as predictors, with cognitive impairment defined by the Mini-Mental State Examination (score &lt
24) as an outcome. Multiple logistic regression analysis was performed to calculate odds ratios (ORs) for cognitive impairment. Results: The mean subject age was 68.9 years, and the prevalence of cognitive impairment was 21.5%. Multivariate analysis revealed that age (p &lt
0.001), low BMI (&lt
21.1
OR 1.39, 95% CI 1.12-1.72), a history of stroke (p = 0.003), a history of myocardial infarction (p = 0.038), low fruit consumption (p for trend = 0.012), and low green tea consumption (p for trend = 0.032) were independently associated with a higher prevalence of cognitive impairment. Conclusions: Modifiable factors, such as low BMI, low fruit consumption, and low green tea consumption, are associated with cognitive impairment. Longitudinal studies will be needed to confirm these findings.

DOI： 10.1159/000447963

Inverse relationship between body mass index and mortality in older nursing home residents: a meta-analysis of 19,538 elderly subjects Reviewed

N. Veronese, E. Cereda, M. Solmi, S. A. Fowler, E. Manzato, S. Maggi, P. Manu, E. Abe, K. Hayashi, J. P. Allard, B. M. Arendt, A. Beck, M. Chan, Y. J. P. Audrey, W. -Y. Lin, H. -S. Hsu, C. -C. Lin, R. Diekmann, S. Kimyagarov, M. Miller, I. D. Cameron, K. H. Pitkala, J. Lee, J. Woo, K. Nakamura, D. Smiley, G. Umpierrez, M. Rondanelli, M. Sund-Levander, L. Valentini, K. Schindler, J. Torma, S. Volpato, G. Zuliani, M. Wong, K. Lok, J. M. Kane, G. Sergi, C. U. Correll

OBESITY REVIEWS 16 ( 11 ) 1001 - 1015 2015.11

Language：English Publisher：WILEY-BLACKWELL

Body mass index (BMI) and mortality in old adults from the general population have been related in a U-shaped or J-shaped curve. However, limited information is available for elderly nursing home populations, particularly about specific cause of death. A systematic PubMed/EMBASE/CINAHL/SCOPUS search until 31 May 2014 without language restrictions was conducted. As no published study reported mortality in standard BMI groups (<18.5, 18.5-24.9, 25-29.9, 30kg/m(2)), the most adjusted hazard ratios (HRs) according to a pre-defined list of covariates were obtained from authors and pooled by random-effect model across each BMI category. Out of 342 hits, 20 studies including 19,538 older nursing home residents with 5,223 deaths during a median of 2 years of follow-up were meta-analysed. Compared with normal weight, all-cause mortality HRs were 1.41 (95% CI=1.26-1.58) for underweight, 0.85 (95% CI=0.73-0.99) for overweight and 0.74 (95% CI=0.57-0.96) for obesity. Underweight was a risk factor for higher mortality caused by infections (HR=1.65 [95% CI=1.13-2.40]). RR results corroborated primary HR results, with additionally lower infection-related mortality in overweight and obese than in normal-weight individuals. Like in the general population, underweight is a risk factor for mortality in old nursing home residents. However, uniquely, not only overweight but also obesity is protective, which has relevant nutritional goal implications in this population/setting.

DOI： 10.1111/obr.12309

Property damage and long-term psychological distress after the 2004 Niigata-Chuetsu earthquake in Ojiya, Japan: a community-based study Reviewed

Kazutoshi Nakamura, Kaori Kitamura, Yoshiharu Kim, Toshiyuki Someya

JOURNAL OF PUBLIC HEALTH 37 ( 3 ) 398 - 405 2015.9

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS

Background This study aimed to assess psychological distress (PD) in earthquake-stricken communities with regard to the extent of property damage for 3 years following the 2004 Niigata-Chuetsu earthquake in Japan.
Methods Subjects were participants of health check examinations in a community near the epicentre, and included 7097 residents (a parts per thousand yen18 years) in 2005, 6586 in 2006 and 6698 in 2007. Interviews assessed PD symptoms and lifestyles. The Kessler Psychological Distress Scale (K10) was used, with scores a parts per thousand yen20 considered as PD. The 137 subdistricts were divided into quartiles according to the proportion of half-completely destroyed houses at cut-offs of 18.9, 30.5 and 66.7%.
Results The PD prevalence was 17.0% in 2005, 13.2% in 2006 and 11.8% in 2007. In 2005, the more and most heavily damaged groups had significantly higher PD prevalence (OR = 1.5 and 1.4, respectively) than that of the least damaged group with a dose-dependent relationship (P = 0.0005). This association was weaker in 2006 (P = 0.0413) and in 2007 (P = 0.1816).
Conclusions Psychological distress prevalence was high in highly damaged areas, and the prevalence difference between areas with high versus low damage decreases with time. Extensive mental health care in communities with substantial damage should be expected to last 2 years after an earthquake.

DOI： 10.1093/pubmed/fdu052

The Interaction Between β-3 Adrenergic Receptor and Peroxisome Proliferator-Activated Receptor Gamma Gene Polymorphism to Periodontal Disease in Community-Dwelling Elderly Japanese. Reviewed International journal

Akihiro Yoshihara, Noriko Sugita, Masanori Iwasaki, Yanming Wang, Hideo Miyazaki, Hiromasa Yoshie, Kazutoshi Nakamura

Journal of periodontology 86 ( 8 ) 955 - 63 2015.8

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: It has been hypothesized that β-3 adrenergic receptor and peroxisome proliferator-activated receptor gamma (PPARγ) might have gene-environmental and gene-gene interactions in periodontal disease. The purpose of this study is to elucidate the interaction between β-3 adrenergic receptor and PPARγ gene polymorphism with periodontal disease. METHODS: Three hundred thirty-two postmenopausal females were enrolled, and their serum high-sensitivity C-reactive protein (hsCRP) and hemoglobin A1c (HbA1c) were examined. β-3 adrenergic receptor and PPARγ genotypes were then determined. An oral examination was performed. The number of remaining teeth was counted, and the probing depth (PD) and clinical attachment level (CAL) were measured. Prevalence-rate ratios (PRRs) were calculated by multiple Poisson regression analyses to evaluate the relationship among periodontal disease markers, such as the number of sites with CAL 4 to 5 or ≥6 mm or PD 4 to 5 or ≥6 mm, and β-3 adrenergic receptor polymorphisms, PPARγ polymorphisms, and the interaction term adjusted by age, hsCRP, and HbA1c, after converting the number of remaining teeth (n) to an offset variable. RESULTS: In the participants with body mass index (BMI) ≥25, PRRs of β-3 adrenergic receptor genotype (Trp/Arg and Arg/Arg) for periodontal disease markers were 0.13 to 0.70 (P <0.0001 to 0.74), those of PPARγ genotype (Pro/Pro) were 0.66 to 3.14 (P = 0.01 to 0.68), and those of the interaction term for the two genotypes were 1.69 to 12.61 (P <0.0001 to 0.33). However, in the participants with BMI <25, a constant tendency was not observed. CONCLUSION: The results confirmed a positive relationship between the interaction term for β-3 adrenergic receptor genotype and PPARγ genotype and various periodontal markers in obese elderly females.

DOI： 10.1902/jop.2015.140472

Prolonged occupational activity and 6-year changes in postural sway in elderly women. Reviewed

Nakamura K, Kitamura K, Oshiki R, Kobayashi R, Saito T, Nishiwaki T

Journal of musculoskeletal & neuronal Interactions. 15 ( 1 ) 78 - 82 2015.3

Impact of demographic, environmental, and lifestyle factors on vitamin D sufficiency in 9084 Japanese adults. Reviewed

Nakamura K, Kitamura K, Takachi R, Saito T, Kobayashi R, Oshiki R, Watanabe Y, Tsugane S, Sasaki A, Yamazaki O

Bone 74 10 - 17 2015.1

Physical activity and 10-year incidence of self-reported vertebral fractures in Japanese women: The Japan Public Health Center-based Prospective Study Reviewed

K. Nakamura, K. Kitamura, M. Inoue, N. Sawada, S. Tsugane

OSTEOPOROSIS INTERNATIONAL 25 ( 11 ) 2565 - 2571 2014.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER LONDON LTD

This study assessed the effects of physical activity on a 10-year incidence of self-reported vertebral fractures in adult women of a large Japanese cohort. Medium levels of strenuous activity and long-duration sedentary activity were associated with a lower incidence of vertebral fractures; association patterns appear to be different from hip fractures.
Physical activity helps prevent hip fracture, but little is known about the longitudinal association between physical activity and vertebral fractures. The purpose of this study was to evaluate the effects of physical activity on the 10-year incidence of symptomatic vertebral fractures using data from the Japan Public Health Center-based Prospective Study.
Baseline studies were conducted in 1993-1994, and the follow-up study was conducted 10 years later. We analyzed 23,757 women aged 40-69 years. At baseline, physical activity was assessed as a predictor by using a questionnaire. Subjects were asked to report vertebral fractures that occurred during the 10-year follow-up period. Relative risks (RRs) adjusted for confounders were estimated by multiple logistic regression analysis.
The 10-year cumulative incidence of vertebral fractures was 0.67 %. Those who engaged in strenuous physical activity of < 1 h/day had a significantly lower incidence of vertebral fractures than those who did not engage in such activity (RR = 0.52, 95 % CI 0.28-0.97), while those engaged in such activity a parts per thousand yen1 h/day did not (RR = 0.82, 95 % CI 0.58-1.14). Long-duration sedentary activity was associated with a low incidence of vertebral fractures (P for trend = 0.0002), but the frequencies of sports activities and metabolic equivalents were not (P for trend = 0.0729 and 0.4341, respectively).
Strenuous activity and sedentary activity are associated with the incidence of vertebral fractures, although the association may not be linear. The pattern of association between physical activity and vertebral fractures appears to be different from that of hip fractures.

DOI： 10.1007/s00198-014-2770-x

Psychological Recovery 5 Years After the 2004 Niigata-Chuetsu Earthquake in Yamakoshi, Japan Reviewed

Kazutoshi Nakamura, Kaori Kitamura, Toshiyuki Someya

JOURNAL OF EPIDEMIOLOGY 24 ( 2 ) 125 - 131 2014.3

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN EPIDEMIOLOGICAL ASSOC

Background: The 2004 Niigata-Chuetsu earthquake of Japan caused considerable damage. We assessed long-term changes in psychological distress among earthquake victims during the period 5 years after the earthquake.
Methods: The participants were people aged 18 years or older living in Yamakoshi, a community in Niigata Prefecture near the epicenter. A self-administered questionnaire survey was conducted annually for 5 consecutive years after the earthquake. Response rates were 1316/1841 (71.5%) in 2005, 667/1381 (48.3%) in 2006, 753/1451 (51.9%) in 2007, 541/1243 (43.5%) in 2008, and 814/1158 (70.3%) in 2009. The questionnaire asked about demographic characteristics, including sex, age, employment status, social network, and psychological status. Psychological distress was assessed using the 12-item General Health Questionnaire and was defined as a total score of 4 or higher.
Results: The overall prevalence of psychological distress decreased (P < 0.0001) gradually from 2005 (51.0%) to 2008 (30.1%) but tended to increase from 2008 to 2009 (P = 0.1590). Subgroup analyses showed that prevalence did not decrease over the 5-year study period among participants with poor social contact (P = 0.0659). From 2008 to 2009 prevalence increased in women (+7.5%, P = 0.0403) and participants aged 65 years or older (+7.2%, P = 0.0400).
Conclusions: The prevalence of psychological distress in Yamakoshi people decreased steadily during the 4 years immediately after the earthquake but appeared to increase thereafter. The earthquake victims are still reestablishing their lives. Thus, continued attention should be focused on maintaining and further assessing their mental health.

DOI： 10.2188/jea.JE20130097

High serum 25-hydroxyvitamin D levels do not retard postmenopausal bone loss in Japanese women: the Yokogoshi study Reviewed

Kaori Kitamura, Kazutoshi Nakamura, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Tomoko Nishiwaki, Masanori Iwasaki, Akihiro Yoshihara

ARCHIVES OF OSTEOPOROSIS 8 ( 1-2 ) 153 2013.12

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER LONDON LTD

We conducted a cohort study exploring an association between serum 25-hydroxyvitamin D (serum 25(OH)D) and parathyroid hormone (PTH) levels and 5-year changes in bone mineral density (BMD) in 482 postmenopausal women. High serum 25(OH)D levels do not retard postmenopausal bone loss within the lumbar spine or femoral neck, and high PTH levels potentially increase hip bone loss.
Purpose The aim of this study was to explore an association between serum 25(OH)D levels and 5-year changes in BMD in postmenopausal women.
Methods This 5-year cohort study included 482 women between 55 and 74 years of age who lived in a community in Japan. Medical examinations were conducted in 2005 and 2010. Data were obtained on baseline serum 25(OH)D and intact parathyroid hormone (iPTH) levels. Outcomes of this study were 5-year changes in BMDs of the lumbar spine and femoral neck. Covariates included years since menopause, body mass index (BMI), lifestyle factors, and weight change. Changes in BMDs among quartiles of serum 25(OH)D were compared with analysis of covariance.
Results The mean age of subjects was 63.1 years, and mean serum25(OH)D levelswere 56.0 nmol/L. Age and decrease in weight were significantly associated with decreases in BMDs of both the lumbar spine (P for trend<0.001 and =0.002, respectively) and femoral neck (P for trend=0.026 and <0.001, respectively); low BMI was associated with a decrease in lumbar spine BMD (P for trend<0.001). No significant associations were found between serum 25(OH)D levels and changes in BMDs. High serum iPTH levels were associated with a greater decrease in femoral neck BMD (P for trend=0.026).
Conclusions High serum 25(OH)D levels do not retard postmenopausal bone loss within the lumbar spine or femoral neck, and high PTH levels potentially increase hip bone loss.

DOI： 10.1007/s11657-013-0153-0

Association between low bone mineral density and clinical attachment loss in Japanese postmenopausal females Reviewed

Masanori Iwasaki, George W. Taylor, Kazutoshi Nakamura, Akihiro Yoshihara, Hideo Miyazaki

Journal of Periodontology 84 ( 12 ) 1708 - 1716 2013.12

Language：English Publishing type：Research paper (scientific journal)

Background: Previous studies have shown conflicting results as to whether low bone mineral density (BMD) is associated with severe clinical attachment loss (AL). The effect of dental restoration on AL was not considered in most studies. In addition, studies of this association in Japanese individuals are limited. The aim of this crosssectional study is to evaluate the possible association between BMD and AL with dental restoration information in Japanese community-dwelling postmenopausal females. Methods: The participants were 397 females (average age: 68.2 years). BMDs of the lumbar spine and right proximal femur were measured by the dual-energy x-ray absorptiometry method. Based on lower BMD/young adult mean (YAM) among the two sites measured, participants were classified into three groups: 1) normal: BMD = 80% YAM or higher (n = 161)
2) osteopenia: BMD = 70% to 80% YAM (n = 136)
and 3) osteoporosis: BMD = &lt
70% YAM (n = 100). Multivariable analyses of the differences in AL values among three BMD groups was conducted using general linear models. Adjustments for the percentage of teeth restored and other covariates were considered. Results: Individuals with osteopenia had significantly higher average AL than individuals with normal BMD (P = 0.022). Additionally, the osteoporosis group displayed significantly higher average AL (P = 0.003) and higher percentages of sites with AL ≥4 mm (P = 0.007). Conclusion: The results of the present study indicate that low systemic BMD was associated with severe AL in Japanese community-dwelling postmenopausal females.

DOI： 10.1902/jop.2013.120613

Association between body mass index and mortality among institutionalized elderly adults in Japan Reviewed

Akemi Nakazawa, Kazutoshi Nakamura, Kaori Kitamura, Yoshiaki Yoshizawa

ENVIRONMENTAL HEALTH AND PREVENTIVE MEDICINE 18 ( 6 ) 502 - 506 2013.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

The purpose of this study is to assess the association between body mass index (BMI) and mortality among nursing home residents in Japan.
A one-year prospective cohort study was conducted with 8,510 elderly individuals across 140 nursing homes. Baseline measurements included age, sex, height, weight, BMI, activities of daily living (ADL) (Barthel Index), and degree of dementia. Information regarding dates of discharge and mortality were also obtained to calculate person-years. Cox's proportional hazards model was used to estimate hazard ratios.
Mean age and BMI were 84.3 [standard deviation (SD) 8.1] years and 20.6 (SD 3.8) kg/m(2), respectively. Hazard ratios of mortality adjusted for sex, age, ADL, degree of dementia, and type of home were 2.4 [95 % confidence interval (CI): 1.9-3.1] for the 1st quintile of BMI (< 17.3 kg/m(2)), 1.7 (95 % CI: 1.3-2.3) for the 2nd quintile (17.3-19.2 kg/m(2)), 1.5 (95 % CI: 1.2-2.0) for the 3rd quintile (19.3-21.1 kg/m(2)), and 1.2 (95 % CI: 0.9-1.6) for the 4th quintile (21.2-23.5 kg/m(2)) (P for trend < 0.001), compared with the reference 5th quintile (23.6a parts per thousand currency sign kg/m(2)).
There was a clear inverse dose-dependent relationship between BMI and mortality. Future studies should be conducted to determine the effects of nutritional intervention on mortality in institutionalized elderly adults.

DOI： 10.1007/s12199-013-0351-9

加齢性運動器疾患の分子疫学コホート研究(村上鮭で元気プロジェクト)

中村和利, 高地リベカ, 北村香織, 斎藤トシ子, 小林量作, 押木利英子, 佐々木綾子, 山崎理, 伊木雅之

日本公衆衛生学会総会抄録集 72回 272 - 272 2013.10

地域住民における血中25-hydroxyvitamin Dレベル村上コホート研究

中村和利, 北村香織, 斎藤トシ子, 小林量作, 押木利英子, 高地リベカ, 佐々木綾子, 山崎理

Osteoporosis Japan 21 ( Suppl.1 ) 219 - 219 2013.9

Association Between Activities of Daily Living and Mortality Among Institutionalized Elderly Adults in Japan Reviewed

Akemi Nakazawa, Kazutoshi Nakamura, Kaori Kitamura, Yoshiaki Yoshizawa

JOURNAL OF EPIDEMIOLOGY 22 ( 6 ) 501 - 507 2012.11

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN EPIDEMIOLOGICAL ASSOC

Background: We assessed the association between activities of daily living (ADL) and mortality among nursing home residents in Japan.
Methods: This I-year prospective cohort study investigated 8902 elderly adults in 140 nursing homes. Baseline measurements included age, sex, height, weight, body mass index (BMI), ADL, and dementia level. ADL levels were obtained by caregivers, using the Barthel Index (BI), after which total BI scores were calculated (higher scores indicate less dependence). Information on dates of discharge and mortality was also obtained to calculate person-years. The Cox proportional hazards model was used to estimate hazard ratios (HRs).
Results: Mean age was 84.3 years, and mean total BI score was 38.5. The HRs of mortality adjusted for sex, age, BM I, and type of nursing home were 7.6 (95% CI: 3.3-17.8) for those with a BI score of 0 (totally dependent), 3.9 (1.7-9.0) for those with a score of 1 to 10, 3.5 (1.4-8.7) for those with a score of 11 to 40, 2.7 (1.4-5.1) for those with a score of 41 to 70, and 1.3 (0.7-2.4) for those with a score of 71 to 99 (P for trend <0.001), as compared with those with a score of 100. Multivariate analysis revealed that BI, sex, age, and BMI were significantly associated with mortality rate.
Conclusions: There was a clear inverse association between ADL level and mortality. In conjunction with other risk factors, ADL level might effectively predict short-term mortality in institutionalized elderly adults.

DOI： 10.2188/jea.JE20110153

Effect of Low-Dose Calcium Supplements on Bone Loss in Perimenopausal and Postmenopausal Asian Women: A Randomized Controlled Trial Reviewed

Kazutoshi Nakamura, Toshiko Saito, Ryosaku Kobayashi, Rieko Oshiki, Kaori Kitamura, Mari Oyama, Sachiko Narisawa, Mitsue Nashimoto, Shunsuke Takahashi, Ribeka Takachi

JOURNAL OF BONE AND MINERAL RESEARCH 27 ( 11 ) 2264 - 2270 2012.11

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Current standard-dose calcium supplements (eg, 1000 mg/d) may increase the risk for cardiovascular events. Effectiveness of lower-dose supplements in preventing bone loss should thus be considered. This study aimed to assess whether calcium supplements of 500 or 250 mg/d effectively prevent bone loss in perimenopausal and postmenopausal Japanese women. We recruited 450 Japanese women between 50 and 75 years of age. They were randomly assigned to receive 500 mg of calcium (as calcium carbonate), 250 mg of calcium, or placebo daily. Medical examinations conducted three times over a 2-year follow-up period assessed bone mineral density (BMD) of the lumbar spine and femoral neck. One-factor repeated measures ANOVA was used for statistical tests. Subgroup analyses were also conducted. Average total daily calcium intake at baseline for the 418 subjects who underwent follow-up examinations was 493 mg/d. Intention-to-treat analysis showed less dramatic decreases in spinal BMD for the 500-mg/d calcium supplement group compared to the placebo group (1.2% difference over 2 years, p = 0.027). Per-protocol analysis (>= 80% compliance) revealed that spinal BMD for the 500 mg/d and 250-mg/d calcium supplement groups decreased less than the placebo group (1.6%, p = 0.010 and 1.0%, p = 0.078, respectively), and that femoral neck BMD for the 500-mg/d calcium supplement group decreased less relative to the placebo group (1.0%, p = 0.077). A low-dose calcium supplement of 500 mg/d can effectively slow lumbar spine bone loss in perimenopausal and postmenopausal women with habitually low calcium intake, but its effect on the femoral neck is less certain. Calcium supplementation dosage should thus be reassessed. (Clinical Trials Registry number: UMIN000001176). (C) 2012 American Society for Bone and Mineral Research.

DOI： 10.1002/jbmr.1676

Effect of low-dose calcium supplements on bone loss in perimenopausal and postmenopausal Asian women: a randomized controlled trial. Reviewed

Nakamura K, Saito T, Kobayashi R, Oshiki R, Kitamura K, Oyama M, Narisawa S, Nashimoto M, Takahashi S, Takachi R

J Bone Miner Res 27 ( 11 ) 2264 - 2270 2012.11

Language：English Publishing type：Research paper (scientific journal)

Current standard-dose calcium supplements (eg, 1000 mg/d) may increase the risk for cardiovascular events. Effectiveness of lower-dose supplements in preventing bone loss should thus be considered. This study aimed to assess whether calcium supplements of 500 or 250 mg/d effectively prevent bone loss in perimenopausal and postmenopausal Japanese women. We recruited 450 Japanese women between 50 and 75 years of age. They were randomly assigned to receive 500 mg of calcium (as calcium carbonate), 250 mg of calcium, or placebo daily. Medical examinations conducted three times over a 2-year follow-up period assessed bone mineral density (BMD) of the lumbar spine and femoral neck. One-factor repeated measures ANOVA was used for statistical tests. Subgroup analyses were also conducted. Average total daily calcium intake at baseline for the 418 subjects who underwent follow-up examinations was 493 mg/d. Intention-to-treat analysis showed less dramatic decreases in spinal BMD for the 500-mg/d calcium supplement group compared to the placebo group (1.2% difference over 2 years, p = 0.027). Per-protocol analysis (>/=80% compliance) revealed that spinal BMD for the 500-mg/d and 250-mg/d cal

DOI： 10.1002/jbmr.1676

Change in bone mineral density and tooth loss in Japanese community-dwelling postmenopausal women: a 5-year cohort study Reviewed

Masanori Iwasaki, Kazutoshi Nakamura, Akihiro Yoshihara, Hideo Miyazaki

JOURNAL OF BONE AND MINERAL METABOLISM 30 ( 4 ) 447 - 453 2012.7

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

The aim of this longitudinal study was to investigate the association between the change in bone mineral density (BMD) and tooth loss in Japanese community-dwelling postmenopausal women. The subjects were 404 women. At baseline (2005) and follow-up (2010), BMDs of the lumbar spine and right femoral neck were measured using dual-energy X-ray absorptiometry (QDR4500a) and participants were classified by tertiles of the annual percentage change in BMD. The number of teeth was counted at the baseline and follow-up to calculate the number of lost teeth over 5 years. Poisson regression analysis was conducted with tertiles of the changes in BMDs of the lumbar spine and femoral neck as the main exposures to estimate their influence on the number of lost teeth. Participants in the tertile with a greater decrease in BMD at each skeletal site (lumbar spine and femoral neck, respectively) had a larger number of lost teeth, controlling for possible confounders. The adjusted relative risks (95% confidence interval) for the mean number of lost teeth in the first, second, and third tertiles were 1.00, 1.15 (0.91-1.45), and 1.38 (1.11-1.72) for the lumbar spine and 1.00, 1.17 (0.93-1.47), and 1.27 (1.01-1.59) for the femoral neck, respectively. In conclusion, a significant relationship exists between a change in BMD and the number of lost teeth during 5-year study period in Japanese community-dwelling postmenopausal women.

DOI： 10.1007/s00774-011-0337-x

The association between renal function and tooth loss in Japanese community-dwelling postmenopausal women Reviewed

Akihiro Yoshihara, Kazutoshi Nakamura, Hideo Miyazaki

GERODONTOLOGY 29 ( 2 ) E363 - E367 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Objectives: This study examined whether low renal function is associated with the number of remaining teeth among community-dwelling elderly Japanese.
Background data: Many elderly individuals display both low renal function and tooth loss.
Materials and Methods: Subjects comprised 405 randomly selected women (55-74 years old). Serum cystatin C level was used to assess renal dysfunction. Multiple linear regression analysis was used to evaluate the relationship between number of remaining teeth and serum cystatin C level, with number of remaining teeth as the dependent variable. Six variables were selected as independent variables in the final model: serum cystatin C; age; mean clinical attachment level; serum cross-linked N-telopeptide of type I collagen level; body mass index and smoking habits.
Results: Multiple linear regression analysis revealed a significant relationship between number of remaining teeth and serum cystatin C level. The beta value for serum cystatin C level for the number of remaining teeth was -0.11 (p = 0.018).
Conclusion: This study indicates a relationship between serum cystatin C level and number of remaining teeth, suggesting that low renal function could be associated with tooth loss.

DOI： 10.1111/j.1741-2358.2011.00481.x

Nutritional and biochemical parameters associated with 6-year change in bone mineral density in community-dwelling Japanese women aged 69 years and older: The Muramatsu Study Reviewed

Kazutoshi Nakamura, Mari Oyama, Toshiko Saito, Rieko Oshiki, Ryosaku Kobayashi, Tomoko Nishiwaki, Mitsue Nashimoto, Yasuo Tsuchiya

NUTRITION 28 ( 4 ) 357 - 361 2012.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

Objective: Predictors of bone loss in elderly Asian women have been unclear. This cohort study aimed to assess lifestyle, nutritional, and biochemical predictors of bone loss in elderly Japanese women.
Methods: Subjects included 389 community-dwelling women aged 69 y and older from the Muramatsu cohort initiated in 2003; follow-up ended in 2009. We obtained data on physical characteristics, osteoporosis treatment (with bisphosphonates or selective estrogen receptor modulators), physical activity, calcium intake, serum 25-hydroxyvitamin D. undercarboxylated osteocalcin, serum albumin, and bone turnover markers as predictors. The outcome was a 6-y change in forearm BMD (Delta BMD). Osteoporosis treatment was coded as 0 for none, 1 for sometimes, and 2 for always during the follow-up period. Stepwise multiple linear regression analysis was used to identify independent predictors of Delta BMD.
Results: Mean age of the subjects was 73.3 y. Mean values of Delta BMD and Delta weight were 0.019 g/cm(2) (-5.8%) and -2.2 kg, respectively. Stepwise multiple linear regression analysis revealed baseline BMD (beta = 0.137, P < 0.0001), osteoporosis treatment beta = 0.0068, P = 0.0105), serum albumin levels (beta = 0.0122, P = 0.0319), and Delta weight (beta = 0.0015, P = 0.0009) as significant independent predictors of Delta BMD. However, none of the other nutritional or biochemical indices were found to be significant predictors of Delta BMD.
Conclusions: Our findings indicate that adequate general nutrition and appropriate osteoporosis medication, rather than specific nutritional regimens, may be effective in preventing bone loss in elderly women. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.nut.2011.05.013

Association between periodontitis and systemic bone mineral density in Japanese community-dwelling postmenopausal women Reviewed

Osamu Takahashi, Akihiro Yoshihara, Kazutoshi Nakamura, Hideo Miyazaki

JOURNAL OF DENTISTRY 40 ( 4 ) 304 - 311 2012.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Objective: The purpose of this cross-sectional study was to evaluate the association between loss of attachment (LA) which is clinical index of periodontitis and bone mineral density (BMD) of the lumbar vertebrae and femur measured with dual energy X-ray absorptiometry (DXA) in Japanese community-dwelling postmenopausal women.
Subjects and methods: Subjects were 347 women aged 55-74. The oral cavity was divided into 6 areas according to the WHO's method for the determination of the clinical attachment level score (CALscore); the LA was measured at 6 sites using a WHO probe in 17, 16, 11, 26, 27, 37, 36, 31, 46, and 47, and the values were recorded in mm. Then, we assessed BMD of the lumbar vertebrae (L2-L4) and femur (femoral neck, proximal part) by DXA. Based on these data, analysis of covariance was used to estimate relation between periodontitis and systemic BMD status excluding effect of age. Multiple linear regression analysis was used to estimate relation between periodontitis and BMD adjusted for 17 variables.
Results: Significant differences were observed in the mean value between the mean CALscore = 0 and CALscore >= 1 groups in the Z value in lumbar vertebrate (106.9 +/- 18.7 vs. 102.3 +/- 1.0, p < 0.05, t-test). Multiple regression analysis was conducted using the mean LA as dependent variable. Lumbar vertebral BMD (regression coefficient: B = -1.039 +/- 0.379, p = 0.007), femoral neck BMD (B = -1.332 +/- 0.627, p = 0.034), and proximal femoral BMD (B = -1.329 +/- 0.536, p = 0.014) all exhibited a significant negative correlation with the mean LA.
Conclusion: A significant negative correlation was observed between periodontal disease and truncal bone BMD in this study. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jdent.2012.01.005

Determination of whether the association between serum albumin and activities of daily living in frail elderly people is causal Reviewed

Kaori Kitamura, Kazutoshi Nakamura, Tomoko Nishiwaki, Kimiko Ueno, Akemi Nakazawa, Mariko Hasegawa

Environmental Health and Preventive Medicine 17 ( 2 ) 164 - 168 2012.3

Language：English Publishing type：Research paper (scientific journal)

Objectives Serum albumin and activities of daily living (ADL) are associated with each other, but whether the association is causal is not known. The purpose of this study was to determine whether a causal association exists between serum albumin and ADL levels. Methods The subjects were 116 frail elderly individuals (34 men and 82 women
mean age 83.0 years). Demographic characteristics, serum albumin, ADL, and handgrip strength were measured at a baseline examination and at a follow-up examination 2 years later. Levels of ADL were assessed with the Barthel Index. Pearson's correlation coefficients were calculated for serum albumin, ADL, and handgrip strength for baseline values and for their 2-year changes (Δ). Results At baseline, the mean serum albumin concentration was 4.0 g/dL and the total score of the Barthel Index (baseline Barthel Index) was 71.1. The baseline serum albumin level correlated significantly with the baseline Barthel Index (r = 0.287) and baseline handgrip strength (r = 0.315), but not with Δ Barthel Index (r = 0.096) or Δ handgrip strength (r = - 0.058). The Δ serum albumin correlated significantly with Δ Barthel Index (r = 0.296), but not with Δ handgrip strength (r = 0.182), baseline Barthel Index (r = - 0.044), or baseline handgrip strength (r = 0.047). Conclusions This 2-year cohort study has demonstrated that a decrease in serum albumin levels is associated with a decrease in ADL levels. A third factor may play a role in adversely affecting both serum albumin and ADL levels in frail elderly people. © The Japanese Society for Hygiene 2011.

DOI： 10.1007/s12199-011-0233-y

Determination of whether the association between serum albumin and activities of daily living in frail elderly people is causal Reviewed

Kitamura K, Nakamura K, Nishiwaki T, Ueno K, Nakazawa A, Hasegawa M

Environ Health Prev Med 17 ( 2 ) 164 - 168 2012.3

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: Serum albumin and activities of daily living (ADL) are associated with each other, but whether the association is causal is not known. The purpose of this study was to determine whether a causal association exists between serum albumin and ADL levels. METHODS: The subjects were 116 frail elderly individuals (34 men and 82 women; mean age 83.0 years). Demographic characteristics, serum albumin, ADL, and handgrip strength were measured at a baseline examination and at a follow-up examination 2 years later. Levels of ADL were assessed with the Barthel Index. Pearson's correlation coefficients were calculated for serum albumin, ADL, and handgrip strength for baseline values and for their 2-year changes (Delta). RESULTS: At baseline, the mean serum albumin concentration was 4.0 g/dL and the total score of the Barthel Index (baseline Barthel Index) was 71.1. The baseline serum albumin level correlated significantly with the baseline Barthel Index (r = 0.287) and baseline handgrip strength (r = 0.315), but not with Delta Barthel Index (r = 0.096) or Delta handgrip strength (r = - 0.058). The Delta serum albumin correlated significantly with Delta Barthel Index (r = 0.296),

DOI： 10.1007/s12199-011-0233-y

Social network disruption as a major factor associated with psychological distress 3 years after the 2004 Niigata-Chuetsu earthquake in Japan Reviewed

Mari Oyama, Kazutoshi Nakamura, Yuko Suda, Toshiyuki Someya

Environmental Health and Preventive Medicine 17 ( 2 ) 118 - 123 2012.3

Language：English Publishing type：Research paper (scientific journal)

Objectives The 2004 Niigata-Chuetsu earthquake of Japan caused a great deal of damage, and people living in the affected region are still struggling to reconstruct their lives. The aim of this study was to determine factors associated with psychological distress in people living in a town at the epicenter 3 years after the earthquake. Methods We conducted a cross-sectional study from June 2007 to January 2008. Participants included 225 individuals living in Kawaguchi (age ≥20 years) who reported psychological symptoms. Information on family structure, employment status, alcohol use, social network, and extent of house damage was elicited by public health nurses conducting structured interviews. Levels of psychological distress were assessed with the Kessler Psychological Distress Scale (K10), with a K10 score ≥25 defined as psychological distress. Results The mean age of participants was 66.1 ± 12.9 years. The prevalence of psychological distress varied among different employment classes, being 5/73 (6.8%) for participants with paid employment, 12/50 (24.0%) for fulltime housewives, and 11/101 (10.9%) for those who were unemployed (χ 2 = 8.42, P = 0.015). It also varied between participants who had lost contact with people in the community and those who had no change in social contact [9/20 (45.0%) vs. 19/189 (10.1%), respectively
χ 2 = 19.04, P&lt
0.001]. Multiple logistic regression analysis showed that age [odds ratio (OR) 0.95, 95% confidence interval (CI) 0.91-0.98], poor or loss of contact with people in the community (OR 6.97, 95% CI 1.85-26.2), and lack of employment (full-time housewives or unemployed individuals) (OR 6.74, 95% CI 1.62-28.0) were associated with psychological distress. Conclusions People who lose their social network are at a very high risk for post-earthquake psychological distress and require appropriate care. © The Japanese Society for Hygiene 2011.

DOI： 10.1007/s12199-011-0225-y

Physical activity and 5-year changes in physical performance tests and bone mineral density in postmenopausal women: The Yokogoshi Study Reviewed

Kaori Kitamura, Kazutoshi Nakamura, Ryosaku Kobayashi, Rieko Oshiki, Toshiko Saito, Mari Oyama, Shunsuke Takahashi, Tomoko Nishiwaki, Masanori Iwasaki, Akihiro Yoshihara

MATURITAS 70 ( 1 ) 80 - 84 2011.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER IRELAND LTD

Objective: The effect of physical activity on musculoskeletal health in older adults is not completely understood. The aim of this study was to determine the relationship between physical activity and 5-year changes in physical performance tests and bone mineral density (BMD) in postmenopausal women.
Study design: The design was a 5-year cohort study.
Main outcome measures: Subjects were 507 women (55-74 years old) living in a rural community in Japan. Physical activity assessed included housework, farm work, and moderate leisure-time physical activity within the previous week. Measurements at baseline included handgrip strength, walking time (timed "Up & Go" test) and BMD of the femoral neck and vertebrae. Five-year changes in these measures (outcome variables) were compared among groups with different levels of physical activity by analysis of covariance.
Results: Women who did not do housework performed worse in changes in handgrip strength (difference = 2.22 kg, P = 0.0201) and worse in changes in the walking time (difference = 0.54 s, P = 0.0072) than those who did housework alone. Women who spent at least 9 h per week (median = 24) doing farm work performed better in changes in handgrip strength (difference = 0.28 kg, P= 0.0334), but worse in changes in the walking time (difference = 0.66 s, P<0.0001) than those who did not do farm work. However, leisure-time activity was not associated with changes in any outcome variable, and none of the physical activities predicted BMD changes.
Conclusions: Engaging in housework and farm work are determinants of physical function in postmenopausal women, which may help them maintain independence in daily living. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.maturitas.2011.06.014

Positive predictive values for self-reported fractures in an adult Japanese population Reviewed

Kazutoshi Nakamura, Manami Inoue, Yoshikazu Kaneko, Shoichiro Tsugane

Environmental Health and Preventive Medicine 16 ( 2 ) 129 - 132 2011.3

Language：English Publishing type：Research paper (scientific journal)

Objectives: Self-reporting provides useful information for assessing the risk factors of osteoporotic fractures in large cohort studies. However, to data, no studies in Japan have confirmed the accuracy of this approach in this context. The aim of the study reported here was to determine the positive predictive value (PPV) for the self-reporting of fractures. Methods: A total of 133 participants of the Oguni cohort in the Japan Public Health Center-based Prospective Study who reported a vertebral, upper limb, or hip fracture on the 15-year follow-up questionnaire survey were evaluated. The accuracy of fractures was confirmed by cross-referencing medical records. Results: The average age of the participants was 72.4 (standard deviation 7.9) years. The PPV for vertebral fracture in the last 15 years was 17/20 (85.0%) for women and 2/9 (22.2%) for men, for a total of 19/29 (65.5%). PPVs for upper limb and hip fractures were as low as 30/68 (44.1%) and 12/22 (54.5%), respectively. Conclusion: Female self-reporting provided PPVs suitable for symptomatic vertebral fracture over 15 years and can be used as an outcome measure in large cohort studies in Japan. © 2010 The Japanese Society for Hygiene.

DOI： 10.1007/s12199-010-0166-x

Postural sway velocity predicts osteoporotic fracture in community-dwelling elderly Japanese women: the Muramatsu Study Reviewed

Kazutoshi Nakamura, Rieko Oshiki, Ryosaku Kobayashi, Mari Oyama, Toshiko Saito, Tomoko Nishiwaki, Mitsue Nashimoto, Yasuo Tsuchiya

AGE AND AGEING 40 ( 1 ) 132 - 135 2011.1

Low Body Mass Index and Low Serum Albumin Are Predictive Factors for Short-Term Mortality in Elderly Japanese Requiring Home Care Reviewed

Kaori Kitamura, Kazutoshi Nakamura, Tomoko Nishiwaki, Kimiko Ueno, Mariko Hasegawa

TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 221 ( 1 ) 29 - 34 2010.5

Language：English Publishing type：Research paper (scientific journal) Publisher：TOHOKU UNIV MEDICAL PRESS

Japan has a rapidly growing elderly population requiring care. This study aimed to clarify risk factors for two-year mortality in such people. Subjects included 205 community-dwelling elderly people, who were approved for care in the 2003 Yamato Study, an epidemiologic study of individuals utilizing the long-term care service system. Demographic characteristics, Barthel index (measuring activities of daily living), grip strength, thigh muscle volume, psychological evaluation, and blood values including hemoglobin, serum albumin, and serum 25-hydroxyvitamin D levels were investigated at baseline. The average age of subjects was 83.6 (S.D., 8.0) years. Of the 205 subjects, 42 died during the follow-up period. Bivariate analysis showed that older age (p = 0.0015), lower weight (p = 0.0087), lower body mass index (BMI) (p = 0.0001), lower Barthel index (p = 0.0017), lower hemoglobin (p = 0.0180), and lower serum albumin (p = 0.0001) were associated with mortality, but that sex was not (p = 0.1248). Stepwise multiple logistic regression analysis showed that BMI < 17.1 kg/m(2) (adjusted OR = 4.0, p = 0.0007), age >= 90 years (adjusted OR = 3.3, p = 0.0033), and lower serum albumin levels (adjusted OR = 0.86, p = 0.0007) were independently associated with mortality. We conclude that low BMI and low serum albumin are strong predictors of 2-year mortality in frail elderly individuals, and that nutritional risk should appropriately be evaluated for elderly people requiring home care.

DOI： 10.1620/tjem.221.29

Long-Term Suicide Mortality Rates Decrease in Men and Increase in Women after the Niigata-Chuetsu Earthquake in Japan Reviewed

Keiko Hyodo, Kazutoshi Nakamura, Mari Oyama, Osamu Yamazaki, Izumi Nakagawa, Kazuo Ishigami, Yasuo Tsuchiya, Masaharu Yamamoto

TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 220 ( 2 ) 149 - 155 2010.2

Language：English Publishing type：Research paper (scientific journal) Publisher：TOHOKU UNIV MEDICAL PRESS

A devastating earthquake causes psychological distress, and may increase suicide mortality thereafter, yet previous studies have made inconsistent conclusions regarding this issue. The purpose of the present study was to determine whether the 2004 Niigata-Chuetsu earthquake in Japan affected long-term mortality from suicide. We conducted a comparative study of suicide mortality rates during the 5-year period preceding and the 3-year period following the earthquake in the disaster area and a control area in Niigata Prefecture, by analyzing death certificate data from October 1, 1999, to September 30, 2007. In men, baseline suicide mortality rates (5 years preceding the earthquake) were 48.4 per 100,000 person-years in the disaster area and 46.1 in the control area, and suicide mortality rates during the 3-year period following the earthquake were 46.0 and 45.1, respectively. In women, baseline suicide mortality rates were 22.3 in the disaster area and 18.7 in the control area, and post-earthquake suicide mortality rates were 20.2 and 15.3, respectively. In consequence, the decrease in suicide mortality rate during the 3 years post-earthquake was significantly higher in the disaster area (2.5) than in the control area (1.0) (p = 0.0013) in men, whereas the decrease in suicide mortality rate was 2.1 in the disaster area and 3.0 in the control area (p = 0.1246) in women. We have concluded that the long-term mortality from suicide after the earthquake decreases in men and increases in women, suggesting that post-earthquake suicide mortality is sex-dependent. Post-earthquake suicide prevention strategies should more aggressively target women.

DOI： 10.1620/tjem.220.149

Intake of dairy products and bone ultrasound measurement in late adolescents: a nationwide crosssectional study in Japan Reviewed

Kazuhiro Uenishi, Kazutoshi Nakamura

ASIA PACIFIC JOURNAL OF CLINICAL NUTRITION 19 ( 3 ) 432 - 439 2010

Language：English Publishing type：Research paper (scientific journal) Publisher：H E C PRESS, HEALTHY EATING CLUB PTY LTD

Introduction: There is little evidence regarding the effects of dairy product intake on bone mineralization among late adolescents, especially in Asians. The aim of this study was to determine the association between dairy product intake and bone strength as measured by quantitative ultrasound (QUS) in a large Japanese population. Methods: Subjects were 38,719 high school students (14,996 males and 23,723 females) across 33 prefectures in Japan. Bone stiffness of the calcaneus was measured by QUS densitometry (AOS-100, Aloka). Subjects were given a self-administered questionnaire, which included questions on gender, age, height, weight, consumption of dairy products, and levels of physical activity. Intake of milk and yogurt were classified as none, 1-99, 100199, 200-399, and >= 400 ml/day. Results: The proportion of subjects who consumed milk 400 ml/day or more was 21% in males and 7.3% in females, while 24% of males and 41.1% of females did not consume milk. After adjusting for physical activity, weight, gender, age, and area of residence, milk intake (R(2)=2.8%, p<0.001) and yogurt intake (R(2)=0.1%, p<0.001) were independently associated with the QUS measurement. Similar associations were found in males and females when a gender-stratified analysis was conducted. Conclusion: We found a positive dose-effect relationship between milk intake and bone strength in late adolescents, to whom we recommend milk intake of 400 ml/day or more to obtain greater bone mass.

Low calcium intake is associated with increased bone resorption in postmenopausal Japanese women: Yokogoshi Study Reviewed

Kazutoshi Nakamura, Toshiko Saito, Akihiro Yoshihara, Miki Ishikawa, Yasuo Tsuchiya, Rieko Oshiki, Ryosaku Kobayashi, Keiko Maruyama, Keiko Hyodo, Mitsue Nashimoto, Naoko Tsugawa, Toshio Okano, Mari Oyama, Masaharu Yamamoto

PUBLIC HEALTH NUTRITION 12 ( 12 ) 2366 - 2370 2009.12

Language：English Publishing type：Research paper (scientific journal) Publisher：CAMBRIDGE UNIV PRESS

Objective: Low Ca intake is common among Japanese women, but its effect Oil bone metabolism has not been fully elucidated. The aim Of the present study was to determine the relationship between Ca intake and serum markers of bone turnover ill postmenopausal Japanese women.
Design: A cross-sectional study.
Setting: A community setting.
Subjects: Subjects were 595 home-dwelling postmenopausal Japanese women. Ca intake was assessed by a validated FFQ, Serum type I collagen cross-linked N-telopeptides (NTX) and osteocalcin Were measured as markers of bone turnover. The relationships between demographic characteristics, lifestyles, serum Ca, vitamin D and intact serum parathyroid hormone and bone turnover were also assessed.
Results: The average age of the subjects was 64.5 (SD 5.8) years and the mean Ca intake was 527 (SD 160) mg/d. Ca intake was significantly associated with serum NTX (P=0.0104); but not with serum osteocalcin. Mean serum NTX concentration in the lowest quartile of Ca intake (<417 mg/d) was significantly higher than in the fourth, referent quartile. Among these Japanese postmenopausal women, very low Ca intake (less than similar to 400 mg/d) was associated with increased bone resorption but not one formation.
Conclusions: Increased bone resorption may be one mechanism by which this Ca-depleted population normalizes bone metabolism and prevents osteoporosis.

DOI： 10.1017/S1368980009005084

Incidence and risk factors associated with hip fracture in institutionalised elderly people in Japan Reviewed

Kazutoshi Nakamura, Shunsuke Takahashi, Mari Oyama, Mitsue Nashimoto, Toshiko Saito, Yasuo Tsuchiya, Yoshiaki Yoshizawa, Masaharu Yamamoto

AGE AND AGEING 38 ( 4 ) 478 - 482 2009.7

Microscopic hematuria is associated with low bone mineral density in aged women and men Reviewed

Kazutoshi Nakamura, Junichiro James Kazama, Yoshifumi Tanaka, Keiko Makabe, Mari Oyama, Yasuo Tsuchiya, Masaharu Yamamoto

JOURNAL OF BONE AND MINERAL METABOLISM 27 ( 2 ) 251 - 254 2009.3

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

Little is known concerning renal or urological risk factors for osteoporosis. The aim of this study was to explore an association between urinalysis and bone mineral density (BMD) in 4,835 Japanese adults. Participants were 4,835 individuals (female 3,683; male 1,152) aged 50 years and over who received a health check-up between January 1995 and March 2006 in Japan. BMD of the distal radius and ulna of the non-dominant forearm was measured by the dual-energy X-ray absorptiometry (DXA) method using a DTX-200 Dexacare osteometer (Osteometer MediTech A/S, Rodovre, Denmark). Urine variables were protein, and red blood cells (RBCs) and white blood cells (WBCs) in urine sediment (categorized as < 1, 1-4, 5-9, or a parts per thousand yen10 cells per high-power microscopic field). Average age was 58.9 years (SD 5.6) in women, and 60.5 years (SD 6.2) in men. Simple linear regression analysis showed that urinary RBCs were associated with BMD in women (beta = -5.88 x 10(-3), R (2) = 0.004, p < 0.0001) and men (beta = -1.34 x 10(-2), R (2) = 0.013, p = 0.0001). These associations held when possible confounders were adjusted (beta = -2.05 x 10(-3), R (2) = 0.001, p = 0.0338 for women and beta = -5.67 x 10(-3), R (2) = 0.006, p = 0.0163 for men). Microscopic hematuria is associated with forearm BMD in women and men aged 50 years and over. Further studies should be conducted to determine the mechanisms underlying this association.

DOI： 10.1007/s00774-008-0027-5

Calcium intake and the 10-year incidence of self-reported vertebral fractures in women and men: The Japan Public Health Centre-based Prospective Study Reviewed

Kazutoshi Nakamura, Norie Kurahashi, Junko Ishihara, Manami Inoue, Shoichiro Tsugane

BRITISH JOURNAL OF NUTRITION 101 ( 2 ) 285 - 294 2009.1

Language：English Publishing type：Research paper (scientific journal) Publisher：CAMBRIDGE UNIV PRESS

The purpose of this study was to evaluate the effect of low Ca intake on the 10-year incidence of vertebral fractures in cohorts I and 11 of the Japan Public Health Centre-based Prospective Study. The baseline studies were conducted in 1990-1994, with the follow-up studies conducted after 10 years. We analysed 33 970 subjects aged 40-59 years in cohort I and 41664 subjects aged 40-69 years in cohort II. At baseline, the intake of Ca was assessed as a predictor, using validated FFQ. A meta-analysis was performed to estimate a summary relative risk (RR) for the two cohort studies. The 10-year cumulative incidences of self-reported vertebral fractures were 0.38% for cohort I and 0.56% for cohort II. In women, lower Ca intake was associated with a higher incidence of vertebral fractures (P for trend=0.001), with the lowest quartile of Ca intake having a significantly higher incidence (0.89/1000 persons per year or RR 2.10 (95% CI 1.25, 3.55)) than that (0.42/1000 persons per year) of the highest. In addition, the RR calculated using energy-adjusted Ca intake (by the residual method) as an outcome was 1.92 (95% Cl 1.28, 2.88). However, no such association was observed in men. An increase of Ca intake should be considered as a preventive strategy for vertebral fractures in peri-and post-menopausal women with a low Ca intake.

DOI： 10.1017/S0007114508993533

Development of a simple food frequency questionnaire to estimate intakes of calcium and other nutrients for the prevention and management of osteoporosis Reviewed

Kazuhiro Uenishi, Hiromi Ishida, Kazutoshi Nakamura

JOURNAL OF NUTRITIONAL SCIENCE AND VITAMINOLOGY 54 ( 1 ) 25 - 29 2008.2

Language：English Publishing type：Research paper (scientific journal) Publisher：CENTER ACADEMIC PUBL JAPAN

There have been no simple methods to estimate dietary nutrient intakes for the prevention and management of osteoporosis. The aim of this study was to develop and validate a new, simple food frequency questionnaire (FFQ) for dietary intake of calcium and other nutrients relevant to the bone health of adult Japanese women. We developed a 28-item FFQ. To validate this, 208 and 72 adult women aged between 18 and 69 y were recruited for testing reliability and reproducibility, respectively. In the 208 women, moderate-to-high Spearman's correlation coefficients between our FFQ and the conventional diet record method were found in intakes of calcium (r=0.668), sodium chloride (NaCl) (r=0.475), vitamin A (r=0.501), vitamin D (r=0.413), vitamin K (r=0.649), and energy (r=0.471). In the 72 women, coefficients of variance of the four repeated measurements of intakes throughout a year were 14.1% for calcium, 7.3% for NaCl, 21.2% for vitamin A, 13.6% for vitamin D, 36.8% for vitamin K, and 9.6% for energy In conclusion, the FFQ we developed is a useful tool to evaluate the intake of dietary calcium of adult Japanese women.. Although it can also measure intakes or dietary vitamin A, vitamin D, vitamin K, NaCl, and energy, further improvement is needed to measure intakes of these nutrients and energy.

DOI： 10.3177/jnsv.54.25

Vitamin D status, bone mass, and bone metabolism in home-dwelling postmenopausal Japanese women: Yokogoshi Study Reviewed

Kazutoshi Nakamura, Naoko Tsugawa, Toshiko Saito, Miki Ishikawa, Yasuo Tsuchiya, Keiko Maruyama, Rieko Oshiki, Ryosaku Kobayashi, Mitsue Nashimoto, Akihiro Yoshihara, Reo Ozaki, Toshio Okano, Masaharu Yamamoto

BONE 42 ( 2 ) 271 - 277 2008.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

Little has been understood about vitamin D status in relation to bone health in Asian women. The purpose of this study was to identify how the serum 25-hydroxyvitamin D (25[OH]D) concentration is associated with bone mass and bone metabolism. This cross-sectional, community-based epidemiologic study was conducted among 600 ambulatory postmenopausal women. The serum 25(OH)D concentration was measured with radioimmunoassay. Other blood biochemical measurements were intact parathyroid hormone and markers of bone turnover, including osteocalcin and type I collagen cross-linked N-telopeptides. Bone mineral density (BMD) of the lumbar spine and right femoral neck were measured with the dual-energy X-ray absorptiometry method using a QDR4500a. The mean serum 25(OH)D concentration was 55.6 nmol/L (SD 14.6). Serum 25(OH)D concentration was linearly associated with BMD of the femoral neck (R-2=0.020, P=0.003), but not with BMD of the lumbar spine. Odds ratios (ORs) for low BMD (defined as t score <= -2.5 SD) were calculated for strata defined by 25(OH)D concentration. The prevalence of low BMD of the lumbar spine was significantly higher in the 40- to 50-nmol/L 25(OH)D group (adjusted OR=3.0, 95% CI: 1.3-7.0) compared to the reference group (>= 70 nmol/L). Prevalence of low BMD for the femoral neck was significantly higher in the 30- to 40-nmol/L (adjusted OR=3.6, 95% CI: 1.1-12.1) and the 40- to 50-nmol/L (adjusted OR=7.6, 95% CI: 2.5-23.2) groups compared to the reference group (>= 70 nmol/L). The mean serum concentration of intact PTH was significantly higher in subjects with serum 25(OH)D < 50 nmol/L compared to those with serum 25(OH)D >= 50 nmol/L. The present study suggests that higher serum 25(OH)D concentrations are associated with increased BMD of the femoral neck, and that a serum 25(OH)D concentration of at least 70 nmol/L is needed to obtain high BMD of the femoral neck, and that of at least 50 nmol/L is needed to achieve normal PTH levels and prevent low BMD in home-dwelling postmenopausal Japanese women. (c) 2007 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bone.2007.09.056

Age-related decrease in serum 25-hydroxyvitamin D concentrations in the frail elderly: a longitudinal study Reviewed

Kazutoshi Nakamura, Tomoko Nishiwaki, Kimiko Ueno, Masaharu Yamamoto

JOURNAL OF BONE AND MINERAL METABOLISM 25 ( 4 ) 232 - 236 2007.7

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

Several cross-sectional studies have demonstrated an age-related decrease in serum 25-hydroxyvitamin D [25(OH)D] concentrations. No prospective studies, however, have been conducted to examine this correlation to date. The objectives of this study were to measure age-related changes in serum 25(OH)D concentrations and to identify predictors of change in serum 25(OH)D concentrations in the frail elderly during a 2-year follow-up period. Eighty elderly subjects (48 women and 32 men) were selected from people utilizing the long-term care insurance system in a community in Japan. All subjects participated in both the baseline and follow-up (2 years later) medical examinations. Baseline measurements included age, height, body mass index, and weight. Additionally, levels of activities of daily living (Barthel index), grip strength, lifestyle, serum 25(OH)D, intact parathyroid hormone (PTH), albumin, total protein, and creatinine concentrations were also determined at baseline. The average age of the subjects was 82.1 years (SD, 8.8). The 2-year decrease in serum 25(OH)D concentrations was calculated to be 6 nmol/l. Multiple linear regression analyses found that the 2-year change (Delta) in the log-transformed 25(OH)D was associated with oalbumin (beta = 0.503, R-2 = 0.288, P < 0.0001), and Delta log-transformed intact PTH was associated with baseline creatinine (beta = 0.453, R-2 = 0.142, P = 0.0006) and Delta log-transformed 25(OH)D (beta = -0.512, R-2 = 0.103, P = 0.0037). In conclusion, serum 25(OH)D concentrations decreased in the 2-year follow-up. This information is useful for the maintenance of vitamin D status and prevention of vitamin D insufficiency in the frail elderly.

DOI： 10.1007/s00774-007-0755-y

Threshold value of serum 25-hydroxyvitamin D concentration in relation to elevated serum parathyroid hormone concentrations in elderly Japanese women Reviewed

Kazutoshi Nakamura, Mitsue Nashimoto, Yasuo Tsuchiya, Toshiko Saito, Tomoko Nishiwaki, Kimiko Ueno, Yoko Okuda, Rieko Oshiki, Masaharu Yamamoto

JOURNAL OF BONE AND MINERAL METABOLISM 24 ( 5 ) 395 - 400 2006.9

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

This study was designed to determine the threshold value for 25-hydroxyvitamin D [25(OH)D] concentration in relation to elevated serum parathyroid hormone (PTH) concentrations in elderly Japanese women. The subjects were 582 noninstitutionalized, ambulant women who lived in a community in Japan. Serum 25(OH)D concentrations were determined using the Nichols Advantage chemiluminescent assay, and serum intact PTH concentrations were determined with a two-site immunoradiometric assay. Demographic characteristics, calcium intake, and serum 1,25(OH)(2)D levels were also determined. The average age, body mass index (BMI), and calcium intake of the subjects were 74.5 years (SD 4.5), 23.3kg/m(2) (SD 3.4), and 579mg/day (SD 248), respectively. The serum log-transformed intact PTH concentration was significantly predicted by the serum 25(OH)D concentration (r = -0.147, P = 0.0004), but not by age, BMI, the serum log-transformed 1,25(OH)(2)D concentration, or the log-transformed calcium intake. Analysis of variance with Dunnett's multiple comparisons showed that mean serum intact PTH concentrations with serum 25(OH)D concentrations less than 30nmol/l (mean intact PTH = 5.89pmol/l, P < 0.0001) and in the range 30-39nmol/l (mean intact PTH = 4.54pmol/l, P = 0.0067) were significantly higher than mean intact PTH concentrations for serum 25(OH)D concentrations greater than 50nmol/l (mean intact PTH = 3.65pmol/l, the baseline level), but the mean serum intact PTH concentration for 25(OH)D concentrations in the range 40-49nmol/l (mean intact PTH = 3.70pmol/l, P = 0.9975) was not. We conclude that serum 25(OH)D for ambulant elderly Japanese women should be maintained at 40nmol/l or higher.

DOI： 10.1007/s00774-006-0699-7

Vitamin D insufficiency in Japanese populations: from the viewpoint of the prevention of osteoporosis Reviewed

K Nakamura

JOURNAL OF BONE AND MINERAL METABOLISM 24 ( 1 ) 1 - 6 2006.1

Language：English Publisher：SPRINGER TOKYO

Low levels of vitamin D nutrition (i.e., vitamin D insufficiency), which potentially cause osteoporosis, have been recognized as a common health problem for elderly people in European and North American countries, but there have been no studies on the prevalence of vitamin D insufficiency in Japan until recently. The aim of this article was to review descriptive features of serum 25-hydroxyvitamin D [25(OH)D] levels and vitamin D insufficiency in Japanese subjects. Reviewing 15 studies pertaining to vitamin D nutritional status recently published for various Japanese populations revealed that: (1) the prevalence of vitamin D insufficiency in active elderly people was as low as 5% or less; (2) the prevalence of vitamin D insufficiency was much higher (up to about 50%) in inactive elderly people than in active elderly people, depending on activities of daily living (ADL); (3) frequent fish consumption helps increase serum 25(OH)D concentrations, especially in winter; and (4) vitamin D nutrition in young women was poorer than people in middle and advanced ages, which may adversely affect bone metabolism. Future studies should focus on the effects of low vitamin D status on bone mass and fractures in Japanese subjects.

DOI： 10.1007/s00774-005-0637-0

Efficacy of optimization of vitamin D in preventing osteoporosis and osteoporotic fractures: A systematic review Reviewed

Kazutoshi Nakamura, Iki Masayuki

Environmental Health and Preventive Medicine 11 ( 4 ) 155 - 170 2006

Language：English

Increased intake or supplementation of vitamin D is often recommended for normal bone health
however, its preventive effect on osteoporosis has not been fully evaluated. The aim of this review is to gather evidence of the efficacy of the optimization of vitamin D nutrition in preventing osteoporosis and osteoporotic fractures. PubMed was used for searching the relevant literature using the MeSH terms "Bone Density (limited to "human", "female", and "English" literature)" or "Fractures (limited to "human", "age ≥45 years", and "English" literature)", and "Vitamin D". The searches yielded 19 randomized controlled trials (RCTs), nine cohort studies, 19 case-control studies, 19 cross-sectional studies, and one meta-analysis. We attempted to answer three questions: 1) does increased vitamin D intake prevent bone loss in peri- and postmenopausal women?, 2) does increased vitamin D intake prevent osteoporotic fractures in the elderly?, and 3) does increased vitamin D intake positively affect peak bone mass attainment in young women? The answer to questions 1 and 2 is that a vitamin D intake of 10-17.5 μg/day (400-700 IU/day) or more is effective in preventing bone loss in late postmenopausal women and an intake of 17.5-20 μg/day (700-800 IU/day) or more together with a calcium supplement reduces the risk of osteoporotic fractures. For question 3, some lines of evidence support the negative effect of low vitamin D nutrition on the attainment of peak bone mass in young women. Further studies are needed to clarify the effect of vitamin D in this age group.

DOI： 10.1265/ehpm.11.155

Vitamin D and prevention of osteoporosis: Japanese perspective Reviewed

Kazutoshi Nakamura

Environmental Health and Preventive Medicine 11 ( 6 ) 271 - 276 2006

Language：English

Vitamin D insufficiency, or a low vitamin D status, is a prevalent condition worldwide. However, there have been no studies addressing this public health issue until recently. In this review article, a summary of a series of studies conducted by the author and his colleagues to determine whether the vitamin D status of Japanese people is adequate and how their vitamin D status affects bone mass and bone metabolism is presented. The observational studies conducted by our group revealed that vitamin D insufficiency does not seem to be a serious problem among active elderly people, but that elderly people with a low level of activities of daily living (ADL) are at a very high risk of vitamin D insufficiency. In young adults, a high intact PTH concentration due to vitamin D insufficiency, which adversely affects their bone mass, is common, suggesting that vitamin D nutrition, as well as dietary calcium intake, should be improved. However, the effects of vitamin D insufficiency among elderly Japanese on bone metabolism, bone mass, and fractures have not been clarified, and should be studied further to determine whether specific preventive strategies, such as vitamin D supplementation, are required for this high-risk group. Intervention studies targeting Japanese populations are required to further address this issue.

DOI： 10.1265/ehpm.11.271

Serum 25-hydroxyvitamin D levels and activities of daily living in noninstitutionalized elderly Japanese requiring care Reviewed

K Nakamura, T Nishiwaki, K Ueno, M Yamamoto

JOURNAL OF BONE AND MINERAL METABOLISM 23 ( 6 ) 488 - 494 2005.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

To date, no study has investigated the nutritional status of vitamin D in frail elderly people living at home. The purposes of this study were to assess serum 25-hydroxyvitamin D ( 25[ OH] D) levels and associated factors in noninstitutionalized elderly people who had various levels of physical disability, and to propose an adequate vitamin D nutritional status for the elderly by interpreting the serum 25( OH) D levels in relation to serum parathyroid hormone ( PTH) levels in this population. Health examinations were conducted in the winter and summer of 2003. The subjects were 143 elderly people in the winter, and 120 elderly people in the summer, who all used the long- term care insurance system at home. Serum 25( OH) D concentrations were determined with a chemiluminescence proteinbinding assay, and serum intact PTH concentrations were determined with an immunoradiometric assay. The subjects' disease histories and lifestyle information were obtained through an interview. Activities of daily living (ADL) levels were evaluated using the Barthel index, and grip strength was measured with a digital hand dynamometer. Average serum 25( OH) D levels in the winter and summer were 54.2 nmol/l (SD 29.0) and 53.3 nmol/l ( SD 32.3), respectively, and intact PTH concentrations in the winter and summer were 4.2 pmol/ l ( SD 1.8) and 4.3 pmol/ l ( SD 1.8), respectively. The proportion of people who had a low 25( OH) D (< 30 nmol/l) and high intact PTH levels (> 6.9 pmol/l) were 15% - 20% and 8%, respectively. Significant predictors of low serum 25( OH) D concentrations were low ADL levels, female sex, and low fish consumption in both seasons. Serum 25( OH) D concentrations of less than 50 nmol/l were associated with elevated serum intact PTH concentrations. In conclusion, elderly people requiring care at home are at high risk of hypovitaminosis D, and their low serum 25( OH) D levels are mainly associated with low ADL levels. In addition, maintenance of serum 25( OH) D concentrations above 50 nmol/ l may prevent hypovitaminosis D-induced hyperparathyroidism.

DOI： 10.1007/s00774-005-0633-4

Nutrition, mild hyperparathyroidism, and bone mineral density in young Japanese women Reviewed

K Nakamura, K Ueno, T Nishiwaki, Y Okuda, T Saito, Y Tsuchiya, M Yamamoto

AMERICAN JOURNAL OF CLINICAL NUTRITION 82 ( 5 ) 1127 - 1133 2005.11

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER SOC CLINICAL NUTRITION

Background: The adverse effects of poor nutrition on the bones of young Asian women have not been fully elucidated.
Objective: The purpose of this study was to investigate possible associations of vitamin D nutrition, calcium intake, and other nutrients with bone metabolism and bone mass in young Japanese women.
Design: The subjects were 108 female college students aged 19-25 y. Dietary nutrients were measured by using the duplicate sampling method on 3 weekdays. Serum 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone, and bone turnover markers were also measured. Bone mineral density (BMD) of the spine and femur was measured by dual-energy X-ray absorptiometry.
Results: The proportions of the subjects with low 25(OH)D (<30 nmol/L) and high intact parathyroid hormone (>= 6.9 pmol/L) concentrations were 32.4% and 15.7%, respectively. Serum 25(OH)D concentrations (P = 0.0265) and calcium intake (P = 0.0103) were inversely associated with serum intact parathyroid hormone. In addition to weight and physical activity, the presence of mild hyperparathyroidism was associated with a low BMD of the lumbar spine (P = 0.0062) and the femoral neck (P = 0.0250), and a low calcium intake was associated with a low BMD of the femoral neck (P 0.0044).
Conclusions: Low calcium intake (based on low BMD of the femoral neck only) and mild hyperparathyroidism (based on low BMD of both the femoral neck and lumbar spine), partly explained by low vitamin D nutrition and a low calcium intake, are important predictors of low BMD in young Japanese women. Effects of poor nutrition and mild hyperparathyroidism on bone peak bone mass in young women should be further investigated in longitudinal studies.

DOI： 10.1093/ajcn/82.5.1127

Intakes of calcium and other nutrients related to bone health in Japanese female college students: A study using the duplicate portion sampling method Reviewed

K Ueno, K Nakamura, T Nishiwaki, T Saito, Y Okuda, M Yamamoto

TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 206 ( 4 ) 319 - 326 2005.8

Language：English Publishing type：Research paper (scientific journal) Publisher：TOHOKU UNIV MEDICAL PRESS

UENO, K., NAKAMURA, K., NISHIWAKI, T., SAITO, T., OKUDA, Y. and YAMAMOTO, M. Intakes of Calcium and Other Nutrients Related to Bone Health in Japanese Female College Students: A Study Using the Duplicate Portion Sampling Method. Tohoku J. Exp. Med., 2005, 206 (4), 319-326 - The purposes of this study were to determine intakes of nutrients related to bone health, such as calcium (Ca), phosphorus (P), sodium (Na), potassium (K), and protein, in Japanese female college students, using the duplicate portion sampling method, and to identify possible lifestyle factors explaining their calcium intakes. Subjects were 106 Japanese female college students aged 19-23 years. All foods in the duplicate portions, as eaten by the subjects during a three-weekday period, were collected. The minerals and protein in the food samples were analyzed. Life-style information was obtained by interview. Levels of cognitive eating restraint (CER) were assessed by the Three-Factor Eating Inventory. Average intakes of dietary Ca, P, Na, K, and protein were 380 (SD 209) mg/day, 649 (SD 212) mg/day, 2,535 (SD 847) mg/day, 1,108 (SD 429) mg/day, and 41.7 (SD 12.6) g/day, respectively. Ca intake was significantly associated with the frequency of milk intake (R-2 = 0.278, p < 0.001), intake of other dairy products (R-2 = 0.338, p < 0.001), and meal skipping (R-2 = 0.161, p < 0.001), but not with CER score (p = 0.378). Female college students are at high risk for poor Ca nutrition. Low intake of nutrients relevant to bone health is considered to adversely affect bone metabolism in young women. bone health; dietary calcium; duplication sampling method; female college student; minerals. (c) 2005 Tohoku University Medical Press.

DOI： 10.1620/tjem.206.319

Health characteristics of elderly Japanese requiring care at home Reviewed

T Nishiwaki, K Nakamura, K Ueno, K Fujino, M Yamamoto

TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 205 ( 3 ) 231 - 239 2005.3

Language：English Publishing type：Research paper (scientific journal) Publisher：TOHOKU UNIV MEDICAL PRESS

The number of elderly subjects requiring care is rapidly increasing, however, their health status has not been well studied. The purposes of this study were to describe the health characteristics of the elderly at home who were using long-term care insurance, and to clarify factors that influence dependence for activities of daily living (ADL). The subjects were 194 elderly people living at home, who were approved for care. The items surveyed were the demographic characteristics, care level (or level of dependence for ADL), Barthel index, grip strength, thigh muscle volume, cognitive impairment using the mini-mental state examination (MMSE), depressed mood using the geriatric depression scale (GDS-15), and serum albumin and hemoglobin levels. The grip strength (p = 0.0001), thigh muscle volume (P = 0.0030), MMSE score (p = < 0.0001) and serum albumin level (p = < 0.0001) decreased, while the GDS-15 score (p = 0.0142) increased with deteriorating care levels. The proportion of subjects not requiring assistance for the items "bathing" and "stair-climbing" in the Barthel index was markedly low in the subjects belonging to the relatively low (mild) care levels. The logistic regression analysis showed that factors associated with dependence for "bathing" and "stair-climbing" were the use of day-services, male sex, decline of grip strength, and a high GDS-15 score. In conclusion, it is important to strengthen the muscles of the upper half of the body, and to correct depressed moods for maintaining levels of ADL in the elderly requiring care at home.

DOI： 10.1620/tjem.205.231

Weight gain in childhood and bone mass in female college students Reviewed

T Saito, K Nakamura, Y Okuda, M Nashimoto, N Yamamoto, M Yamamoto

JOURNAL OF BONE AND MINERAL METABOLISM 23 ( 1 ) 69 - 75 2005.1

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

The attainment of maximal peak bone mass early on in life is one of the most important strategies for the prevention of osteoporosis in women. The aim of this study was to clarify the correlation between gains in body size in all growth phases in childhood and adult bone mass in women. The subjects were 86 female first-year university students, aged 18-21 years. We measured the subjects' bone mineral content (BMC) and bone mineral density (BMD) at the lumbar spine and the left hip, including the femoral neck, with dual energy X-ray absorptiometry. Each subject was measured for current height and weight. Height and weight at birth, and at 1.5, and 3 years were obtained from each maternity record book, and those between 6 and 18 years were obtained from their school health records. Other information, including physical activity and calcium intake, was obtained through an interview. Bivariate analysis showed that weight gains during the periods from birth to 1.5 years and from 9 to 12 years significantly correlated with both BMC and BMD values at any site. The stepwise method of multiple regression analysis showed that a weight gain during the period from birth to 1.5 years was significantly associated with BMC at the lumbar spine (P=0.0001) and at the femoral neck (P=0.0290) and with BMD at the lumbar spine (P=0.0387). Birth weight was significantly associated with BMC at the lumbar spine (P=0.0474) and the total hip (P=0.0352), and weight gain during the period from 9 to 12 years was significantly associated with BMC at the femoral neck (P=0.0376). In conclusion, birth weight and weight gain in infancy are important determinants of bone mass in young women. Additionally, a girl's prepubertal growth spurt is likely to be a key phase for the acquisition of bone mass in relation to body weight. Our findings suggest that osteoporosis prevention programs may need to start very early in the life cycle.

DOI： 10.1007/s00774-004-0543-x

Dietary calcium, sodium, phosphorus, and protein and bone metabolism in elderly Japanese women: A pilot study using the duplicate portion sampling method Reviewed

K Nakamura, Y Hori, M Nashimoto, Y Okuda, H Miyazaki, Y Kasai, M Yamamoto

NUTRITION 20 ( 4 ) 340 - 345 2004.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

OBJECTIVES: Associations between dietary factors and bone metabolism in Asians have not been thoroughly investigated. The purpose of this study was to determine the effect of dietary intake of calcium (Ca), phosphorus (P), sodium (Na), and protein on bone metabolism in elderly Japanese women by the duplicate portion sampling method.
METHODS: The subjects were 43 healthy female volunteers (mean age, 68.3 y; standard deviation, 6.8). Dietary nutrients were directly determined by using a 24-h duplicate meal portion. Serum osteocalcin and bone alkaline phosphatase and urinary deoxypyridinoline (DPD) and type I collagen cross-linked N-telopeptides (NTX-I) were measured as markers of bone turnover. Hormones related to bone metabolism, including serum 25-hydroxyvitainin D-3, 1,25-dihydroxyvitamin D-3, and intact parathyroid hormone also were determined. Urinary parameters were corrected for urinary creatinine concentration.
RESULTS: The mean (standard deviation) daily dietary intakes of Ca, P, Na, and protein were 660 (195) mg, 996 (208) mg, 4080 (1142) mg, and 63.9 (15.5) g, respectively. Dietary Ca was negatively correlated with urinary DPD (r = -0.417, P = 0.005) and NTX-I (r = -0.324, P = 0.034), and dietary P was negatively correlated with urinary DPD (r = -0.307, P = 0.045). Multiple regression analysis showed that only dietary Ca was associated with urinary DPD and NTX-I. Dietary Ca intake was significantly associated with bone resorption markers, but no other dietary factors were associated with any of the biochemical markers.
CONCLUSION: The major factor having an adverse effect on the bone health of the elderly Japanese women is low Ca intake and not other dietary minerals or protein.

DOI： 10.1016/j.nut.2003.12.004

Nutritional covariates of dietary calcium in elderly Japanese women: Results of a study using the duplicate portion sampling method Reviewed

K Nakamura, Y Hori, M Nashimoto, Y Okuda, H Miyazaki, Y Kasai, M Yamamoto

NUTRITION 19 ( 11-12 ) 922 - 925 2003.11

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

OBJECTIVES: The purposes of this study were to determine the intake of nutrients related to bone health, including calcium (Ca), phosphorus (P), sodium (Na), potassium (K), protein, and vitamin D, in elderly Japanese women and to examine possible intercorrelations between Ca intake and other nutrients.
METHODS: Fifty-three elderly women in a rural community in Japan participated by supplying duplicate meat samples of everything they ate during a 24-h period. Dietary Ca, P, Na, K, protein, and vitamin D intakes were examined. The mean (standard deviation) age of the 53 women was 68.2 y (6.4 y).
RESULTS: The mean (standard deviation) intakes of dietary Ca, P, Na, K, protein, and vitamin D were 670 (219) mg/d, 1019 (267) mg/d, 4203 (1341) mg/d, 2752 (844) mg/d, 65.2 (18.3) g/d, and 9.90 (8,89) mug/d, respectively. Dietary Ca was significantly correlated with dietary P (r = 0.732, P < 0.0001), Na (r = 0.336, P = 0.0140), K (r = 0.571, P < 0.0001), and protein (r = 0.563, P < 0.0001), but not with vitamin D. After adjusting the data to reflect the total dry weight, dietary Ca was still correlated with P (r = 0.696, P < 0.0001), K (r = 0.423, P = 0.0018), and protein (r = 0.405, P = 0.0029).
CONCLUSIONS: The intake of dietary nutrients relevant to bone health in ambulatory Japanese elderly women was examined and documented. The potential confounding effects of these nutrients, especially P, K, and protein, should be taken into account when evaluating the effects of dietary Ca on bone health in observational studies. (C) Elsevier Inc. 2003.

DOI： 10.1016/S0899-9007(03)00181-3

Effects of dietary habits and CYP1A1 polymorphisms on blood dioxin concentrations in Japanese men. Reviewed International journal

Yasuo Tsuchiya, Satoshi Nakai, Kazutoshi Nakamura, Kunihiko Hayashi, Junko Nakanishi, Masaharu Yamamoto

Chemosphere 52 ( 1 ) 213 - 9 2003.7

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The major source of dioxin impurities in Japan in the past was agrochemical formulations; more recently, it has been exhaust from waste incinerators. To examine the environmental and genetic factors that influence blood dioxin concentration, we investigated the relationship among dioxin concentrations, dietary habits and cytochorome P450 1A1 (CYP1A1) polymorphisms (MspI type and Ile-Val type) in Japanese fishermen and farmers, including also a group of office workers as controls. The mean dioxin concentrations in the fishermen, the farmers and the controls were 161369, 79079 and 100500 pg/g fat, respectively. The elevated dioxin concentration with polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and coplanar-PCBs found in the fishermen may be due to the frequent consumption of fish; no such relationship was found both in the farmers and the controls. We found that the concentrations of congeners found as impurities in certain chemicals such as those previously used in agriculture showed no significant differences among the three groups; we consider it unlikely that the farmers would be directly exposed to dioxins from such chemicals. Thus, it is probable that the primary route of dioxin exposure in the Japanese population is through the food chain via fish consumption, regardless of occupation. No meaningful relationship between blood dioxin concentration and CYP1A1 polymorphisms was found in this study, although there was a significant difference between the concentration of total non-ortho-PCBs in genotypes A and B. Further studies on more subjects, including those of genotype C, are needed to confirm the relationship between blood dioxin concentrations and MspI polymorphisms.

DOI： 10.1016/S0045-6535(03)00110-3

Correlates of bone mineral density in elderly women living in nursing homes for the disabled in Japan Reviewed

K Nakamura, M Nashimoto, S Matsuyama, M Hatakeyama, M Yamamoto

AGING CLINICAL AND EXPERIMENTAL RESEARCH 14 ( 6 ) 485 - 490 2002.12

Language：English Publishing type：Research paper (scientific journal) Publisher：EDITRICE KURTIS S R L

Background and aims: Characteristics of bone aging in the institutionalized elderly are not well known. The aim of this study was to determine the factors correlated with the forearm bone mineral density (BMD) in elderly women with disability. Methods: Of 175 female residents living in nursing homes for the disabled in Niigata, Japan, 119 agreed to participate and underwent medical examinations in 1999; 107 (age range, 66-100) met our inclusion criteria. We measured forearm BMD by dual-energy X-ray absorptiometry (DXA), and the serum concentrations of 25-hydroxyvitamin D-3, 1,25-dihydroxyvitamin D-3, intact parathyroid hormone, albumin, total protein, and creatinine. Body weight, score of activities of daily living, and history of femoral neck fractures were also recorded. Results: Forearm BMD decreased with age, and the regression equation was BMD=0.9035exp, (-0.0179Age) (R-2=0.170, p<0.0001). Multiple linear regression analysis revealed that only age (R-2=0.178, p<0.0001), and serum creatinine (R-2=0.153, p<0.0001) and albumin (R-2=0.051, p=0.005) concentrations were independently associated with log-BMD. Twenty-five of the 107 subjects had a history of femoral neck fracture, and only serum albumin concentration (p=0.031) was shown to be associated with fracture history. Conclusions: Forearm BMD was associated with age, serum creatinine and albumin, which may be useful parameters for assessing the bone health of elderly women with disability.

Fish as a major source of vitamin D in the Japanese diet Reviewed

K Nakamura, M Nashimoto, Y Okuda, T Ota, M Yamamoto

NUTRITION 18 ( 5 ) 415 - 416 2002.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

OBJECTIVES: We investigated the amount and sources of vitamin D in the Japanese diet by analyzing diet records collected over a 4-mo period.
METHODS: Dietary data for this study were provided by a nursing home in Niigata, Japan. Diet records, written by the nursing home's dietitian, for 122 consecutive days between September and December 1999, were used. The amount of food for an individual was weighed before cooking and recorded on the diet record. Vitamin D-containing foods, including fish, eggs, meat, and mushrooms, were selected from the diet records, and their vitamin D (vitamin D2 plus D3) per day was calculated by referring to the Standard Tables of Food Composition in Japan.
RESULTS: The overall average vitamin D intake per day was 7.10 mug (284 IU), which is about 70% of the recommended dietary allowance of 10 mug (400 IU). There were no significant differences in vitamin D values over the 4 mo (P = 0.822). Overall, the contribution of vitamin D from fish to total vitamin D intake was 90.7%, followed by mushrooms (4.4%), eggs (3.2%), and meat (1.7%).
CONCLUSIONS: Frequent fish intake appears to be an advisable health practice in terms of preventing vitamin D insufficiency in the elderly. (C)Elsevier Science Inc. 2002.

DOI： 10.1016/S0899-9007(02)00751-7

Hypovitaminosis D and hyperparathyroidism in physically inactive elderly Japanese living in nursing homes: Relationship with age, sunlight exposure and activities of daily living

M Nashimoto, K Nakamura, S Matsuyama, M Hatakeyama, M Yamamoto

AGING CLINICAL AND EXPERIMENTAL RESEARCH 14 ( 1 ) 5 - 12 2002.2

Language：English Publishing type：Research paper (scientific journal) Publisher：EDITRICE KURTIS S R L

Background and aims: The purposes of this study were to investigate the prevalences of hypovitaminosis D and hyperparathyroidism in physically inactive elderly people living in Japanese nursing homes and determine any correlations with demographic, environmental and/or life-style factors. Methods: We targeted 220 elderly people living in nursing homes for the physically disabled in Japan. Of these, 133 (women, 113; men, 20) subjects who agreed and met our inclusion criteria were studied. The average age of the subjects was 84.6 years (SD 8.2). Serum 25-hydroxyvitamin D-3(25[OH]D-3), intact parathyroid hormone (intact PTH), creatinine, and albumin concentrations were measured in each subject. Total hours of sunshine during the previous 5 weeks, activities of daily living (ADL) levels, and dietary vitamin D intake were also measured. ADL levels were evaluated using the Physical Self-Maintenance Scale (5-point scale). The examinations were performed between October and December, 1999. Results: The average concentrations of serum 25(OH)D-3 and intact PTH were 29.9 nmol/L (SD 13.1) and 5.04 pmol/L (SD 2.27), respectively. The prevalences of hypovitaminosis D (25[OH]D-3<30 nmol/L) and hyperparathyroidism (intact PTH>6.90 pmol/L) were 771133 (57.9%) and 21/133 (15.8%), respectively. Serum 25(OH)D-3 concentrations were positively associated with hours of sunshine (R-2=0.371, p<0.001) and serum albumin concentrations (R-2=0.086, p<0.001), but not with age (p=0.075) or total ADL score (p=0.527). A negative association between serum intact PTH and 25(OH)D-3 levels was found in subjects who were 80 years or older (p<0.001) but not in subjects under the age of 80 years. Conclusions: Hypovitaminosis D and hyperparathyroidism are commonly seen in elderly Japanese with low ADL levels. Hypovitaminosis D seems to adversely affect PTH levels, especially in the very elderly.

Low serum concentrations of 25-hydroxyvitamin D in young adult Japanese women: A cross sectional study

K Nakamura, M Nashimoto, S Matsuyama, M Yamamoto

NUTRITION 17 ( 11-12 ) 921 - 925 2001.11

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

OBJECTIVES: The vitamin D nutrition status of young adult women is unclear, but a recent preliminary report suggested that they may have vitamin D insufficiency. This study assessed the serum concentrations of 25-hydroxyvitamin D (25[OH]D), an index of vitamin D nutrition status, in young adult Japanese women in comparison with those in older women and investigated whether serum 25(OH)D concentrations are associated with other calcium-related hormones and bone mass.
METHODS: A cross sectional study of 77 healthy women, age 19 to 66 y, working in nursing homes in Japan was conducted in the winter of 1999 and 2000. The investigation included blood tests, forearm bone mass measurements, and a lifestyle questionnaire,
RESULTS: The mean serum 25(OH)D concentration in women younger than 30 y was 34.0 nmoL/L (standard deviation [SD] = 11.0) and significantly lower than that in women 30 y and older (50.0 nmol/L, SD = 14.4). The proportion of subjects younger than 30 y who had serum 25(OH)D concentrations less than 30 nmol/L was 42.1% and was significantly higher (P < 0.001) than the proportion of those 30 y and older (10.3%). There was a weak but significant linear association between serum 25(OH)D concentrations and forearm bone, mineral content (R-2 = 0.114, P = 0.0052) but not between serum 25(OH)D concentrations and bone mineral density. The association held after adjusting for body weight (R2 = 0.139, P = 0.0111). Serum intact parathyroid hormone concentrations were within the normal range and not associated with serum 25(OH)D concentrations.
CONCLUSIONS: Serum 25(OH)D concentrations in young adult Japanese women (< 30 y old) are lower than those of older adult women (30 to 66 y), and lower serum 25(OH)D concentrations are likely associated with lower forearm bone mineral content. (C) Elsevier Science Inc. 2001.

DOI： 10.1016/S0899-9007(01)00662-1

Prevalence of anorexia nervosa and bulimia nervosa in a geographically defined area in Japan Reviewed

Kazutoshi Nakamura, Masaharu Yamamoto, Osamu Yamazaki, Yoshiaki Kawashima, Kensuke Muto, Toshiyuki Someya, Koji Sakurai, Shinichi Nozoe

International Journal of Eating Disorders 28 ( 2 ) 173 - 180 2000.9

Language：English Publishing type：Research paper (scientific journal)

Objective: Little has been understood regarding the frequency of eating disorders in Japan. This study was designed to identify the prevalence of anorexia nervosa (AN) and bulimia nervosa (BN) in Japan. Method: We asked doctors in all of the relevant medical facilities (130 hospitals and 1,326 clinics) in Niigata Prefecture to report patients with DSM-IV-diagnosed eating disorders who appeared or were admitted between 20-24 October 1997. The response rate was 94.4%. Results: The estimated point prevalences of AN and BN were 4.79 and 1.02, respectively, per 100,000 females. Specifically for the age group of 15-29 years, the prevalence of AN was 17.10 and that of BN 5.79. Discussion: The prevalence of AN and BN in Japan is lower than that for European Caucasian populations. This result may be due to cultural and ethnic differences and/or it may be a transient phenomenon. (C) 2000 by John Wiley and Sons, Inc.

DOI： 10.1002/1098-108X(200009)28:2<173::AID-EAT6>3.0.CO;2-I

Serum 25-hydroxyvitamin D concentrations and related dietary factors in peri- and postmenopausal Japanese women

K Nakamura, M Nashimoto, Y Hori, M Yamamoto

AMERICAN JOURNAL OF CLINICAL NUTRITION 71 ( 5 ) 1161 - 1165 2000.5

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER SOC CLINICAL NUTRITION

Background: Few studies of vitamin D nutrition in Asian populations have been conducted.
Objective: The objective was to assess 25-hydroxyvitamin D [25(OH)D] concentrations in healthy elderly Japanese women during the winter and to determine whether 25(OH)D concentrations are associated with lifestyle.
Design: We investigated 151 women aged 66.5 +/- 6.7 y ((x) over bar +/- SD) living in a rural community in February 1999. Serum 25(OH)D and intact parathyroid hormone were measured by using HPLC and an immunoradiometric assay, respectively. Information on lifestyle factors, including sunshine exposure and the consumption of vitamin D-rich foods, was also obtained through an interview.
Results: The mean (+/- SD) 25(OH)D concentration was 59.9 +/- 17.0 nmol/L. Vitamin D insufficiencies (<30 nmol/L) were found in 4.6% of the women, a value lower than that found in white populations. No correlation was found between age and 25(OH)D concentrations (r = 0.004, P = 0.957). The 25(OH)D concentration of subjects who consumed fish frequently (greater than or equal to 4 times/wk) was 10.1 nmol/L higher (P < 0.001) than that of subjects with a moderate consumption of fish (1-3 times/wk). Additionally, those who did not consume eggs had significantly lower 25(OH)D concentrations than did those who consumed eggs greater than or equal to 1 time/wk (P < 0.05).
Conclusions: The nutritional status of vitamin D in Japanese populations seems to be better than that in most Western populations. Frequent fish consumption is believed to help maintain adequate concentrations of serum 25(OH)D in elderly Japanese women during the winter.

Age and sex differences in the bone mineral density of the distal forearm based on health check-up data of 6343 Japanese

K Nakamura, Y Tanaka, K Saitou, M Nashimoto, M Yamamoto

OSTEOPOROSIS INTERNATIONAL 11 ( 9 ) 772 - 777 2000

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER-VERLAG LONDON LTD

Bone mineral density (BMD) predicts osteoporotic fractures. The incidence of osteoporotic fractures in Japan is lower than among Caucasians, but fewer data on the BMD of Asians have been reported. This study attempted to clarify the age and sex differences in the forearm BMD of healthy adult to assess racial differences between Japanese and Caucasians. The subjects were 6343 healthy adult Japanese (5281 females, 1062 males) who underwent a health check-up at a health care service center between February 1995 and August 1999. Subjects' age ranged from 15 to 80 years. The BMD of the distal radius and ulna of the non dominant forearm was measured by dual-energy X-ray absorptiometry. Overall, the forearm BMD of men was greater than that of women in all age groups. Peak BMD was 0.484 g/cm(2) in the 40-44 year age group of women and 0.590 g/cm(2) in the 30-34 year age group of men. The forearm BMD of women under 50 years of age (the average age at menopause) increased slightly with age (2.0%/decade, p<0.0001), but it did not among their male counterparts. After 50 years of age, BMD of the women decreased linearly (-1.6%/year, p<0.0001) with age, the rate of decrease being 1.7-fold faster than in their male counterparts. Rates of gain and loss of forearm BMD differ between the sexes. In comparison with data previously reported, we did not find any evidence of racial differences in BMD as an explanation for the lower incidence of osteoporotic fractures in Japan.

DOI： 10.1007/s001980070056

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