Yasutake Tomata

Green tea consumption and the risk of incident functional disability in elderly Japanese: the Ohsaki Cohort 2006 Study

Background: Previous studies have reported that green tea consumption is associated with a lower risk of diseases that cause functional disability, such as stroke, cognitive impairment, and osteoporosis. Although it is expected that green tea consumption would lower the risk of incident functional disability, this has never been investigated directly. Objective: The objective was to determine the association between green tea consumption and incident functional disability in elderly individuals. Design: We conducted a prospective cohort study in 13,988 Japanese individuals aged ≥65 y. Information on daily green tea consumption and other lifestyle factors was collected via questionnaire in 2006. Data on functional disability were retrieved from the public Long-term Care Insurance database, in which subjects were followed up for 3 y. We used Cox proportional hazards regression analysis to investigate the association between green tea consumption and functional disability. Results: The 3-y incidence of functional disability was 9.4% (1316 cases). The multiple-adjusted HR (95% CI) of incident functional disability was 0.90 (0.77, 1.06) among respondents who consumed 1–2 cups green tea/d, 0.75 (0.64, 0.88) for those who consumed 3–4 cups/d, and 0.67 (0.57, 0.79) for those who consumed ≥5 cups/d in comparison with those who consumed <1 cup/d (P-trend < 0.001). Conclusion: Green tea consumption is significantly associated with a lower risk of incident functional disability, even after adjustment for possible confounding factors.

The Ohsaki Cohort 2006 Study: Design of Study and Profile of Participants at Baseline

Background Large-scale cohort studies conducted in Japan do not always include psychosocial factors as exposures. In addition, such studies sometimes fail to satisfactorily evaluate disability status as an outcome. Methods This prospective cohort study comprised 49 603 (22 438 men and 27 165 women) community-dwelling adults aged 40 years or older who were included in the Residential Registry for Ohsaki City, Miyagi Prefecture, in northeastern Japan. The baseline survey, which included psychosocial factors, was conducted in December 2006. Follow-up of death, immigration, cause of death, cancer incidence, and long-term care insurance certification was started on 1 January 2007. Results The response rate was 64.2%. In general, lifestyle-related conditions in the study population were similar to those of the general Japanese population; however, the proportion of male current smokers was higher in the cohort. The association between age and the proportion of those reporting psychological distress showed a clear U-shaped curve, with a nadir at age 60 to 69 years in both men and women, although more women were affected by such distress than men. The proportion of those who reported a lack of social support was highest among those aged 40 to 49 years. Most men and women surveyed did not participate in community activities. Among participants aged 65 years or older, 10.9% of participants were certified beneficiaries of the long-term care insurance system at baseline. Conclusions The Ohsaki Cohort 2006 Study is a novel population-based prospective cohort study that focuses on psychosocial factors and long-term care insurance certification.

Green tea consumption is associated with lower psychological distress in a general population: the Ohsaki Cohort 2006 Study

BACKGROUND Although green tea or its constituents might reduce psychological stress, the relation between green tea consumption and psychological distress has not been investigated in a large-scale study. OBJECTIVE Our aim was to clarify whether green tea consumption is associated with lower psychological distress. DESIGN We analyzed cross-sectional data for 42,093 Japanese individuals aged > or =40 y from the general population. Information on daily green tea consumption, psychological distress as assessed by the Kessler 6-item psychological distress scale, and other lifestyle factors was collected by using a questionnaire. We used multiple logistic regression analyses adjusted for age, sex, history of disease, body mass index, cigarette smoking, alcohol consumption, time spent walking, dietary factors, social support, and participation in community activities to investigate the relation between green tea consumption and psychological distress. RESULTS We classified 2774 (6.6%) of the respondents as having psychological distress (Kessler 6-item psychological distress scale > or =13/24). There was an inverse association between green tea consumption and psychological distress in a model adjusted for age and sex. Although the relation was largely attenuated when possible confounding factors were adjusted for, a statistically significant inverse association remained. The odds ratio (with 95% CI) of developing psychological distress among respondents who consumed >/=5 cups of green tea/d was 0.80 (0.70, 0.91) compared with those who consumed <1 cup/d. These relations persisted when respondents were stratified by social support subgroups or by activities in communities. CONCLUSION Green tea consumption was inversely associated with psychological distress even after adjustment for possible confounding factors.

Association between sleep duration, weight gain, and obesity for long period.

BACKGROUND Although previous studies showed the long-term effects of sleep duration on risk of weight gain, Western tends to gain weight irrespective of sleep duration over a long period. Conversely, it is showed that body mass index (BMI) decreases during a long period in Japanese and thus, the long-term effect of sleep duration on weight gain and obesity is still unclear in Asia. METHODS We followed up 13,629 participants aged 40-79years and prospectively collected data from 1995 to 2006. We divided the participants into five groups according to their self-reported sleep duration: ⩽5h (short sleep), 6h, 7h (reference), 8h, and ⩾9h (long sleep). The main outcome was ⩾5kg weight gain or BMI⩾25kg/m(2) (obesity). We used logistic regression analyses to derive odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for several confounding factors. RESULTS We observed no association between sleep duration and risk of ⩾5kg weight gain and obesity. After stratification by BMI, long sleepers had a significantly increased risk of ⩾5kg weight gain (OR: 1.36, 95%CI: 1.09-1.70) in obese participants. CONCLUSIONS Among community-dwelling Japanese, only obese long sleepers have a significantly increased long-term risk of ⩾5kg weight gain.

Significance of the Hemorrhagic Site for Recurrent Bleeding: Prespecified Analysis in the Japan Adult Moyamoya Trial

Background and Purpose— The primary results of the Japan Adult Moyamoya Trial revealed the statistically marginal superiority of bypass surgery over medical treatment alone in preventing rebleeding in moyamoya disease. The purpose of this analysis is to test the prespecified subgroup hypothesis that the natural course and surgical effects vary depending on the hemorrhagic site at onset. Methods— The hemorrhagic site, classified as either anterior or posterior, was the only stratifying variable for randomization. Statistical analyses were focused on the assessment of effect modification according to the hemorrhagic site and were based on tests of interaction. Results— Of 42 surgically treated patients, 24 were classified as anterior hemorrhage and 18 as posterior hemorrhage; of 38 medically treated patients, 21 were classified as anterior and 17 as posterior. The hazard ratio of the primary end points (all adverse events) for the surgical group relative to the nonsurgical group was 0.07 (95% confidence interval, 0.01–0.55) for the posterior group, as compared with 1.62 (95% confidence interval, 0.39–6.79) for the anterior group (P=0.013 for interaction). Analysis within the nonsurgical group revealed that the incidence of the primary end point was significantly higher in the posterior group than in the anterior group (17.1% per year versus 3.0% per year; hazard ratio, 5.83; 95% confidence interval, 1.60–21.27). Conclusions— Careful interpretation of the results suggests that patients with posterior hemorrhage are at higher risk of rebleeding and accrue greater benefit from surgery, subject to verification in further studies. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: C000000166.

Associations of Body Mass Index, Smoking, and Alcohol Consumption With Prostate Cancer Mortality in the Asia Cohort Consortium

Many potentially modifiable risk factors for prostate cancer are also associated with prostate cancer screening, which may induce a bias in epidemiologic studies. We investigated the associations of body mass index (weight (kg)/height (m)(2)), smoking, and alcohol consumption with risk of fatal prostate cancer in Asian countries where prostate cancer screening is not widely utilized. Analysis included 18 prospective cohort studies conducted during 1963-2006 across 6 countries in southern and eastern Asia that are part of the Asia Cohort Consortium. Body mass index, smoking, and alcohol intake were determined by questionnaire at baseline, and cause of death was ascertained through death certificates. Analysis included 522,736 men aged 54 years, on average, at baseline. During 4.8 million person-years of follow-up, there were 634 prostate cancer deaths (367 prostate cancer deaths across the 11 cohorts with alcohol data). In Cox proportional hazards analyses of all cohorts in the Asia Cohort Consortium, prostate cancer mortality was not significantly associated with obesity (body mass index >25: hazard ratio (HR) = 1.08, 95% confidence interval (CI): 0.85, 1.36), ever smoking (HR = 1.00, 95% CI: 0.84, 1.21), or heavy alcohol intake (HR = 1.00, 95% CI: 0.74, 1.35). Differences in prostate cancer screening and detection probably contribute to differences in the association of obesity, smoking, or alcohol intake with prostate cancer risk and mortality between Asian and Western populations and thus require further investigation.

Tooth Loss and Mortality in Elderly Japanese Adults: Effect of Oral Care

To assess whether oral care (tooth brushing, regular dental visits, and use of dentures) affects mortality in elderly individuals with tooth loss.

The association between self-reported history of physical diseases and psychological distress in a community-dwelling Japanese population: the Ohsaki Cohort 2006 Study

BACKGROUND Patients with physical disease are known to suffer considerable psychological distress. Social support may confound the association between physical disease and psychological distress. Population-based epidemiological studies have not been conducted on the association between history of physical disease, psychological distress and social support. METHODS Using cross-sectional data from 2006, we studied 43 487 community-dwelling people aged ≥40 years living in Japan. We examined the association between 13 self-reported histories of physical disease and psychological distress evaluated using the Kessler 6-item psychological distress scale (K6), defined as ≥13 points out of 24. To investigate the association, we performed multiple logistic regression analyses adjusted for age, gender, social support and possible confounders. Social support, as the interaction between physical disease and psychological depression, was tested through the addition of cross-product terms to the multivariate-adjusted model. RESULTS The following histories of physical disease were found significantly and positively associated with psychological distress: cancer, diabetes mellitus, hyperlipidemia, hypertension, myocardial infarction, stroke, gastric or duodenal ulcer, liver disease, arthritis, osteoporosis, kidney disease and fall or fracture (odds ratio, 1.2-2.3). Social support did not modify the association between most histories of physical disease and psychological distress. CONCLUSIONS Subjects with a history of physical disease were significantly and positively associated with psychological distress, and social support did not modify this association for most physical diseases. Even after patients have left hospital following treatment for physical disease, they require continuous monitoring for psychological distress by doctors and paramedics.

Dietary Patterns and Incident Functional Disability in Elderly Japanese: The Ohsaki Cohort 2006 Study

BACKGROUND To date, little is known about the association between dietary pattern and disability in older adults. The present prospective cohort study investigated the association between dietary patterns and incident functional disability. METHODS Information on food consumption and other lifestyle factors was collected from Japanese older persons aged ≥65 years via a questionnaire. Three dietary patterns (Japanese pattern, animal food pattern, and high dairy pattern) were derived using principal component analysis of the consumption of 39 food and beverage items. Data on functional disability were retrieved from the public Long-term Care Insurance database, in which participants were followed up for 5 years. The Cox model was used to estimate the multivariate-adjusted hazard ratios of incident functional disability. RESULTS Among 14,260 participants, the 5-year incidence of functional disability was 16.6%. The Japanese pattern score was associated with a lower risk of incident functional disability (hazard ratio of the highest quartile vs the lowest, 0.77; 95% confidence interval: 0.68-0.88; p trend <.001). An animal food pattern and a high dairy pattern tended to have a higher risk of incident functional disability, but not to a significant degree. CONCLUSIONS In Japanese older persons, the Japanese dietary pattern is associated with a decreased risk of incident functional disability.

Relationship Between Serum Adiponectin Levels and Disability-Free Survival Among Community-Dwelling Elderly Individuals: The Tsurugaya Project

BACKGROUND Mortality risk tends to be higher among elderly individuals with higher serum adiponectin levels. The objective of this study was to clarify whether the relationship between adiponectin and a higher risk of disability or death can be explained by physical function, bone mineral density, depression, and malnutrition. METHODS We analyzed 505 individuals who underwent comprehensive geriatric assessment and who agreed to provide information on long-term care insurance. The endpoint was the composite outcome of death and incident disability defined as a first certification for any level of care need. Relationships between adiponectin and incident disability or death were estimated using the Cox proportional hazards model. RESULTS During 6 years of follow-up, 179 incident disabilities or deaths occurred. Among them, 20 and 23 died with and without disability, respectively. The risk of incident disability or death was significantly higher among participants with adiponectin greater than or equal to 22.4 (90%) than 8.0 or less (25%) mg/L (Hazard ratio: 95% confidence interval, 1.92: 1.01-3.64) in the model adjusted for age, sex, and metabolic risk factors. Adjustment for N-terminal pro-B-type natriuretic peptide and nutritional status did not substantially alter this risk estimate, although the association ceased to be statistically significant. Adjustment for physical function did attenuate the relationship, however, which ceased to be apparent upon exclusion of disability or death occurring within 3 years of follow-up. CONCLUSION The relationship between adiponectin and the composite outcome of incident disability and death was at least partly explained by reduced physical function and wasting in participants with higher adiponectin levels.