No effect of the Trp64Arg variant of the beta3-adrenergic receptor gene on weight loss by diet and exercise intervention among Japanese adults.

Controversy remains as to whether the presence of the tryptophan-to-arginine (Trp64Arg) variant of the beta(3)-adrenergic receptor gene impedes the magnitude of body weight loss by diet and exercise intervention. The objectives of the present study were to compare the changes in body weight between carriers and noncarriers of the Trp64Arg variant before and after 6 months of diet and exercise interventions for weight loss. A total of 37 middle-aged Japanese individuals (12 carriers and 25 noncarriers of the Trp64Arg variant) participated in the study. There were no significant differences in body weight between the 2 groups at the baseline. There were significant reductions in body weight both in carriers and noncarriers, but no significant differences between the 2 groups with respect to changes in these variables. The weight changes were -2.52 kg (95% confidence interval [CI], -3.56 to -1.48) among carriers and -1.89 kg (95% CI, -2.65 to -1.13) among noncarriers, and the change in the variant carrier group minus the change in the variant noncarrier group was -0.47 (95% CI, -1.97 to 1.02). These results suggest that the presence of the Trp64Arg variant of the beta(3)-adrenergic receptor gene may not play a major role as a hindrance to weight reduction.

Body mass index and cardiovascular disease mortality in Japan: the Ohsaki Study.

OBJECTIVE: Although there is a clear positive association between obesity and the incidence and severity of cardiovascular disease, the association between underweight and cardiovascular disease is unclear. The objective of this study was to examine the relation between body mass index (BMI) and cardiovascular disease in Japan, where the proportion of the population that is underweight is relatively high. METHOD: A total of 43,916 Japanese adults (21,003 men and 22,913 women) aged 40 to 79 years who had no history of cancer, ischemic heart disease (IHD), or stroke participated in the baseline survey in 1994. Hazard ratios (HR) and their 95% confidence intervals (CIs) for death due to total cardiovascular disease, all strokes, ischemic stroke, hemorrhagic stroke, and IHD were calculated according to BMI by using Cox's proportional hazards regression models. The 22.5-24.9 kg/m(2) BMI category was used as the reference category in all analyses. RESULTS: There were U-shaped associations between BMI and total cardiovascular disease, all stroke, hemorrhagic stroke, and IHD mortality, and a J-shaped association between BMI and ischemic stroke mortality. Participants with a BMI <18.5 kg/m(2) had a significantly increased risk of total cardiovascular disease, all stroke, hemorrhagic stroke, and IHD mortality, and the multivariate HR (95% CI) was 1.62 (1.19-2.19), 1.50 (1.02-2.21), 2.11 (1.07-4.17), 1.83 (1.11-3.01), respectively. CONCLUSION: Underweight was substantially associated with hemorrhagic stroke and IHD mortality in Japan, while obesity was associated with increased risk of total cardiovascular disease mortality and mortality from individual cardiovascular diseases.

Personality and body mass index: a cross-sectional analysis from the Miyagi Cohort Study.

OBJECTIVE: Obesity is an increasingly prevalent public health problem worldwide, and is associated with a higher risk of developing various noncommunicable diseases. To further examine the association between personality and overweight, obesity, or underweight, we conducted a cross-sectional analysis in Japan. We hypothesized that extraversion and psychoticism would have a positive association with overweight, and that neuroticism and lie would have an inverse association with overweight, whereas the association between personality and underweight would be the reverse image of overweight. METHODS: In 1990, 30,722 subjects (40-64 years of age) completed a self-administered questionnaire including body weight and height and the Japanese version of the Eysenck Personality Questionnaire-Revised Short Form. Multivariate logistic regression analysis was used to calculate odds ratios for overweight [body mass index (BMI)> or =25.0 kg/m2] or underweight (BMI<18.5) relative to each category on the personality subscale. RESULTS: In men and women, extraversion and psychoticism had positive associations with overweight, whereas neuroticism had an inverse association. Lie had an inverse association with overweight in men. In men and women, only extraversion had an inverse association with underweight and neuroticism had a positive association with underweight. CONCLUSION: Our findings indicate that personality is associated with both overweight and underweight. These results may provide clues to devising more effective measures for preventing overweight, obesity, or underweight or for weight control intervention.

Coffee consumption and the risk of colorectal cancer: a prospective cohort study in Japan.

An inverse association between coffee consumption and the risk of colorectal cancer has been reported in several case-control studies, but results from prospective cohort studies have been inconclusive. We conducted a prospective cohort study among a Japanese population to clarify the association between coffee consumption and the risk of colorectal cancer incidence. We used data from the Miyagi Cohort Study for this analysis. Usable self-administered questionnaires about coffee consumption were returned from 22,836 men and 24,769 women, aged 40-64 years, with no previous history of cancer. We used the Cox proportional-hazard regression model to estimate hazard ratios and 95% confidence intervals. During 11.6 years of follow-up (425,303 person-years), we identified 457 cases of colorectal cancer. Coffee consumption was not associated with the incidence of colorectal, colon or rectal cancer. The multivariate-adjusted hazard ratio (95% confidence interval) of colorectal cancer incidence for 3 or more cups of coffee per day as compared with no consumption was 0.95 (0.65-1.39) for men and women (p for trend = 0.55), 0.91 (0.56-1.46) for men (p for trend = 0.53) and 1.16 (0.60-2.23) for women (p for trend = 0.996). Coffee consumption was also not associated with incidence of either proximal or distal colon cancer. We conclude that coffee consumption is not associated with the incidence risk of colorectal cancer in the general population in Japan.

Obesity and depressive symptoms in elderly Japanese: the Tsurugaya Project.

OBJECTIVE: The aim of this study is to examine the association between obesity and depressive symptoms in Japan. METHODS: We conducted a cross-sectional study of 1128 community-dwelling elderly Japanese aged 70 years or older in 2002. We calculated the body mass index [BMI=weight (kg)/height (m)2] from measured weight and height and evaluated depressive symptoms using the 30-item Geriatric Depression Scale (GDS 30), with a cut-off point of 11. RESULTS: In men, no apparent association was observed between BMI and depressive symptoms. An inverse linear trend was observed in women overall, but stratified analysis of chronic medical conditions, such as stroke or cancer, showed an inverse association was evident only among women with the conditions. Among women without these chronic conditions, no apparent association was evident. CONCLUSION: No apparent association was observed in men overall or in apparently healthy women. An inverse trend was observed only in women with chronic medical conditions.