Green Tea Consumption and the Risk of Incident Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study.

OBJECTIVE: Biologic studies have shown that certain components of green tea may have protective effects on neurocognition. However, because of the lack of human epidemiologic studies, the impact of green tea consumption on the incidence of dementia has never been confirmed. The objective of this cohort study was to clarify the association between green tea consumption and incident dementia. METHODS: In this 5.7-year prospective cohort study, using a questionnaire, information on daily green tea consumption and other lifestyle factors was collected from elderly Japanese individuals aged 65 years or more. Data on incident dementia were retrieved from the public Long-term Care Insurance Database. RESULTS: Among 13,645 participants, the 5.7-year rate of incident dementia was 8.7%. More frequent green tea consumption was associated with a lower risk of incident dementia (hazard ratio for ≥5 cups/day versus <1 cup/day: 0.73; 95% confidence interval: 0.61-0.87). The lower risk of incident dementia was consistent even after selecting participants who did not have subjective memory complaints at the baseline. CONCLUSION: Green tea consumption is significantly associated with a lower risk of incident dementia.

Body mass index and the risk of incident functional disability in elderly Japanese: The OHSAKI Cohort 2006 Study.

The relationship between the body mass index (BMI) and the incidence of cause-specific disability remains unclear.We conducted a prospective cohort study of 12,376 Japanese individuals aged ≥65 years who were followed up for 5.7 years. Information on BMI and other lifestyle factors was collected via a questionnaire in 2006. Functional disability data were retrieved from the public Long-term Care Insurance database. BMI was divided into 6 groups (<21, 21-<23, 23-<25, 25-<27[reference], 27-<29 and ≥29). Hazard ratios and 95% confidence intervals for cause-specific disability were estimated using Cox proportional hazards regression models.A U-shaped relationship between BMI and functional disability was observed, with a nadir at 26. The nadir BMI values with the lowest disability risk were 28 for dementia, 25 for stroke, and 23 for joint disease. A low BMI (<23) was a risk factor for disability due to dementia, the HR values (95% CI) being 2.48 (1.70-3.63) for BMI <21 and 2.25 (1.54-3.27) for BMI 21 to <23; a high BMI (≥29) was a risk factor for disability due to joint disease, the HR value (95% CI) being 2.17 (1.40-3.35). There was no significant relationship between BMI and disability due to stroke.The BMI nadirs for cause-specific disability differed: a low BMI (<23) was a risk factor for disability due to dementia, and a high BMI (≥29) was a risk factor for disability due to joint disease. Because BMI values of 23 to <29 did not pose a significantly higher risk for each cause of disability, this range should be regarded as the optimal one for the elderly population.

Dietary Patterns and Incident Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study.

BACKGROUND: Although it has been speculated that the Japanese dietary pattern has a preventive effect against incident dementia, no reported study has yet investigated this issue. The present prospective cohort study investigated the association between dietary patterns and incident dementia in elderly Japanese subjects. METHODS: We analyzed follow-up data covering a 5.7-year period for 14,402 older adults (≥65 years) participating in a community-based, prospective cohort study. 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 assessed using a food frequency questionnaire. Data on incident dementia were retrieved from the public Long-term Care Insurance database. RESULTS: With 71,043 person-years of follow-up, incidence of dementia was 9.0%. The score for the Japanese dietary pattern was associated with a lower risk of incident dementia (hazard ratio of the highest quartile vs the lowest, 0.80; 95% confidence interval: 0.66-0.97; p-trend = .016). The animal food pattern and the high-dairy pattern showed no significant association with incident dementia. CONCLUSIONS: In this population of elderly Japanese individuals, the Japanese dietary pattern was associated with a decreased risk of incident dementia.

Defecation frequency and cardiovascular disease mortality in Japan: The Ohsaki cohort study.

BACKGROUND: It has been suggested that constipation is associated with cardiovascular disease (CVD). The association between defecation frequency and CVD mortality in a large population has not been reported hitherto. The aim of this study was to examine whether defecation frequency is related to CVD mortality. METHODS AND RESULTS: A total of 45,112 eligible Japanese men and women aged 40-79 years participated in the Ohsaki Cohort study. Defecation frequency was evaluated at the baseline using a self-administered questionnaire. Hazard ratios (HRs) and 95% confidence intervals (CIs) for cardiovascular disease mortality were calculated according to defecation frequency (≥ 1 time/day, 1 time/2-3 days, ≤ 1 time/4 days) by the Cox proportional hazards model. During 13.3 years of follow-up, 2028 participants died due to CVD. Compared with those in the ≥ 1 time/day group, the risk of overall CVD mortality was significantly higher in the 1 time/2-3 days and ≤ 1 time/4 days groups; the multivariate HR (95%CI) for 1 time/2-3 days and ≤ 1 time/4 days was 1.21 (95% CI: 1.08-1.35) and 1.39 (95% CI: 1.06-1.81), respectively. CONCLUSION: A lower defecation frequency was associated with risk of CVD mortality in this Japanese population. Future studies, aiming at elucidating the mechanisms underlying the associations between chronic constipation and risk of CVD mortality, may be facilitated by our findings.

Association between Coffee Consumption and Incident Risk of Disabling Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study.

Epidemiological studies of the association between coffee consumption and dementia have yielded inconsistent results. Therefore, we investigated the association between coffee consumption and incident risk of dementia in an elderly Japanese population. 23,091 subjects aged ≥65 y living in Ohsaki City, northeastern Japan, responded to the baseline survey in 2006. Of these, we analyzed 13,137 subjects who gave informed consent and were not disabled at baseline. The outcome was the incidence of disabling dementia defined by usage of the Long-term Care Insurance database. We used the Cox proportional hazards regression model for multivariate analysis. During 5.7 y of follow-up period, we identified 1,107 cases of incident dementia. Overall, coffee consumption was significantly associated with a lower risk of incident dementia. The multivariate-adjusted HRs for the incidence of dementia according to coffee consumption categories (never, occasionally, 1-2 cups/d, and ≥3 cups/d) were 1.00, 0.73 (95% CI, 0.62-0.86), 0.72 (95% CI, 0.61-0.84), and 0.82 (95% CI, 0.65-1.02; p for trend = 0.009), respectively. In addition, this significant inverse association was more remarkable among women, non-smokers, and non-drinkers. Coffee consumption is significantly associated with a lower risk of incident dementia.

Predominant expression of mutated allele of the succunate dehydrogenase D (SDHD) gene in the SDHD-related paragangliomas.

Recent studies indicate that succinate dehydrogenase (SDH) genes B, C, or D are, at least partly, involved in the pathogenesis of pheochromocytoma or paraganglioma. Of these three genes, the SDHD gene mutation is most closely related with paragangliomas of the neck. Here we describe a case of an SDHD-related paraganglioma, in which we studied the molecular characteristics of an SDHD mutation to evaluate the involvement of SDHD in neck paragangliomas. Genetic testing revealed a heterozygous G106D mutation in the SDHD gene. In the tumor tissue, loss of heterozygosity was demonstrated by real time polymerase chain reaction (PCR). In the present case of SDHD mutated paragangliomas, wild type SDHD gene expression was markedly reduced possibly due to loss of heterozygosity not due to imprinting of SDHD gene in the tumors.

Aldosterone-producing adenoma accompanied with renal artery stenosis.

We describe a case of secondary hypertension in which aldosterone-producing adenoma (APA) and renal artery stenosis (RAS) coexisted. RAS caused a significant pressure gradient, and successful angioplasty of it improved the affected renal function but did not reduce the systemic blood pressure (SBP). Surgical resection of APA performed several months later reduced SBP. In cases of suspected secondary hypertension, other cause(s) of hypertension should be considered, if hypertension persists after correction of one possible cause.