The association between neighborhood social capital and self-reported dentate status in elderly Japanese--the Ohsaki Cohort 2006 Study.

OBJECTIVES: Little is known about the influence of social capital on dental health. The aim of the present cross-sectional study was to determine the association between neighborhood social capital, individual social networks and social support and the number of remaining teeth in elderly Japanese. METHODS: In December 2006, self-administered questionnaires were sent to 31,237 eligible community-dwelling individuals (response rate: 73.9%). Included in the analysis were 21,736 participants. Five neighborhood social capital variables were calculated from individual civic networks, sports and hobby networks, volunteer networks, friendship networks and social support variables. We used multilevel logistic regression models to estimate the odds ratio (OR) of having 20 or more teeth according to neighborhood social capital variables with adjustment for sex, age, individual social networks and social support, educational attainment, neighborhood educational level, dental health behavior, smoking status, history of diabetes and self-rated health. RESULTS: The average age of the participants was 74.9 (standard deviation; 6.6) years, and 28.5% of them had 20 or more teeth. In the univariate multilevel model, there were statistically significant associations between neighborhood sports and hobby networks, friendship networks and self-reported dentate status. In the multivariable multilevel model, compared with participants living in lowest friendship network neighborhoods, those living in highest friendship network neighborhoods had an OR 1.17 (95% confidence interval, 1.04-1.30) times higher for having 20 or more teeth. CONCLUSIONS: There is a significant association between one network aspect of neighborhood social capital and individual dentate status regardless of individual social networks and social support.

Fish consumption and the risk of colorectal cancer: the Ohsaki Cohort Study.

BACKGROUND: Evidence from laboratory and animal studies suggests that high fish consumption may reduce the risk of colorectal cancer, but the results of studies in humans have been inconsistent. The objective of this study was to prospectively examine the association between fish consumption and the risk of colorectal cancer incidence in Japan, where fish is widely consumed. METHODS: We analysed data from 39 498 men and women registered in the Ohsaki National Health Insurance Cohort Study who were 40-79 years old and free of cancer at the baseline. Fish consumption was assessed at the baseline using a self-administered food frequency questionnaire. RESULTS: During 9 years of follow-up, we identified 566 incident cases of colorectal cancer (379 men and 187 women). The hazard ratios and 95% confidence intervals (CIs) for colorectal cancer incidence in the highest quartile of fish consumption compared with the lowest quartile were 1.07 (95% CIs; 0.78-1.46, P-trend=0.43) for men, and 0.96 (95% CIs; 0.61-1.53, P-trend=0.69) for women. CONCLUSION: The results of this prospective cohort study revealed no association between fish consumption and the risk of colorectal cancer.

Increase in body mass index category since age 20 years and all-cause mortality: a prospective cohort study (the Ohsaki Study).

BACKGROUND: It is still unclear whether weight gain from early to late adulthood affects longevity. Furthermore, no study has addressed its association with all-cause and cause-specific mortality in an Asian population. METHODS: We prospectively assessed the association between an increase in body mass index (BMI) category since age 20 years and risk of all-cause, cardiovascular disease (CVD) and cancer mortality. Self-reported information pertaining to BMI was collected from 38 080 Japanese men and women aged 40-79 years at study entry in 1994 after exclusion of participants with a BMI of <18.5 kg/m(2) at age 20 years or at study entry. We defined six patterns of increase in BMI category at age 20 years and study entry: stable normal, overweight and obese, normal to overweight or obese, and overweight to obese. RESULTS: During 7 years of follow-up, 2617 participants died. After adjustment for potential confounders, we observed a significantly increased risk of all-cause mortality for the pattern of normal weight at age 20 years and obese at study entry and of stable obese compared with stable normal in BMI category, the multivariate HRs (95% confidence interval (CI)) being 1.42 (1.08-1.88) and 2.26 (1.45-3.51), respectively. For the pattern of overweight at age 20 years and obese at study entry, the multivariate hazard ratio (95% CI) was 1.35 (0.92-1.98). In contrast, we did not observe an increased risk of all-cause mortality for normal weight at age 20 years and overweight at study entry, and stable overweight. For CVD and cancer mortality, these results were consistently observed. CONCLUSION: We observed an increased risk of all-cause mortality both among participants who had been persistently obese since early adulthood and participants who showed an increase in BMI category from normal to obese, compared with participants with a stable normal BMI category.

Sleep duration and the risk of breast cancer: the Ohsaki Cohort Study.

In a prospective study of 23 995 Japanese women, short sleep duration was associated with higher risk of breast cancer (143 cases), compared with women who slept 7 h per day, the multivariate hazard ratio of those who slept