Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study

OBJECTIVES: It has been hypothesized that dietary fiber intake has a beneficial impact on prevention of dementia, but the epidemiological evidence is scant. We sought to examine whether dietary fiber intake is inversely associated with risk of dementia requiring care under the national insurance (disabling dementia). METHODS: The study setting was the Circulatory Risk in Communities Study, involving 3739 Japanese individuals aged 40-64 years at the dietary surveys (1985-99). Dietary fiber intake was estimated using the 24-hour dietary recall method. Incident disabling dementia was followed up from 1999 through 2020. Disabling dementia was further classified into that with or without a history of stroke. Hazard ratios of disabling dementia according to quartiles of total, soluble, and insoluble fiber intake were calculated using the Cox proportional hazards model. RESULTS: During a median 19.7-year follow-up, a total of 670 cases of disabling dementia developed. Dietary fiber intake was inversely associated with risk of dementia: the multivariate hazards ratios (95% confidence intervals) were 0.83 (0.67-1.04), 0.81 (0.65-1.02), and 0.74 (0.57-0.96) for individuals with the second, third, and highest quartiles of dietary fiber intake, respectively, as compared with the lowest quartile (P for trend = 0.03). The inverse association was more evident for soluble fiber intake and was confined to dementia without a history of stroke. As for fiber-containing foods, potatoes, but not vegetables or fruits, showed a similar association. CONCLUSIONS: Dietary fiber intake, especially soluble fiber, was inversely associated with risk of disabling dementia in a general Japanese population

Serum uric acid and risk of stroke and its types: the Circulatory Risk in Communities Study (CIRCS)

The role of serum uric acid as a predictor of stroke among the general Japanese population remains controversial. We conducted a prospective cohort study of 5235 men and 8185 women aged 40-79 years at baseline between 1985 and 1994 in four Japanese communities, who were initially free from stroke, coronary heart disease, and medication for hyperuricemia or gout. Cox proportional hazards models were used to estimate sex-specific hazard ratios of stroke and its types in relation to serum uric acid level. During a median follow-up of 23.1 years, we recorded 1018 (488 men and 530 women) incident strokes, including 222 (99 and 123) intraparenchymal hemorrhages, 113 (33 and 80) subarachnoid hemorrhages and 667 (347 and 320) ischemic strokes. After adjustment for age, community and known cardiovascular risk factors, the multivariable hazard ratios (95% CIs) in the highest vs. lowest quintile of serum uric acid were 1.45 (1.07-1.96) for total stroke, 1.20 (0.65-2.20) for intraparenchymal hemorrhage, 1.46 (0.69-3.09) for subarachnoid hemorrhage and 1.61 (1.07-2.41) for ischemic stroke in women. The corresponding multivariable hazard ratios (95% CIs) in men were 1.02 (0.74-1.35), 0.83 (0.40-1.72), 1.19 (0.38-3.75) and 1.00 (0.70-1.41). Furthermore, those positive associations with risks of total and ischemic strokes in women were more evident in nonusers of antihypertensive medication than the users. In conclusion, elevated serum uric acid level is an independent predictor of total stroke in women but not in men. The positive association in women was mostly attributable to ischemic stroke and was more pronounced among nonusers of antihypertensive medication

The Circulatory Risk in Communities Study (CIRCS): A Long-Term Epidemiological Study for Lifestyle-Related Disease Among Japanese Men and Women Living in Communities

The Circulatory Risk in Communities Study (CIRCS) is an ongoing community-based epidemiological study of lifestyle-related disease involving dynamic prospective cohorts of approximately 12,000 adults from five communities of Japan: Ikawa, Ishizawa and Kita-Utetsu (Akita Prefecture), Minami-Takayasu (Osaka Prefecture), Noichi (Kochi Prefecture), and Kyowa (Ibaraki Prefecture). One of the most notable features of CIRCS is that it is not only an observational cohort study to identify risk factors for cardiovascular diseases (CVD), such as stroke, coronary heart disease, and sudden cardiac death, but it also involves prevention programs for CVD. Using basic, clinical, epidemiological, and statistical techniques, CIRCS has clarified characteristics of CVD and the related risk factors to develop specific methodologies towards CVD prevention in Japanese middle-aged or older adults for more than half a century

循環器疾患のコホート研究と統計科学

要旨ありヘルスサイエンスと統計科学研究詳

Anger Expression and the Risk of Cardiovascular Disease Among Urban and Rural Japanese Residents: The Circulatory Risk in Communities Study

Objective It has been suggested that urbanization, which has been expanding rapidly for the past several decades, increases the risk of cardiovascular disease (CVD) associated with psychological factors such as anger, but the evidence is limited. We examined the hypothesis that urbanicity modifies the association of anger expression with the risk of CVD.Methods A prospective study was conducted in 5936 residents of urban and rural communities aged 40 to 79 years who had completed an annual health checkup including a questionnaire on anger expression between 1995 and 1998. Associations of anger expression with the risk of CVDs were examined using Cox proportional hazards models, after adjusting for classical cardiovascular risk factors.Results During a median follow-up of 16.6 years, we identified 312 incident CVDs. The means (SDs) of anger expression were 24.7 (5.8) among urban residents and 24.6 (5.7) among rural participants (p = .87). Among urban residents, anger expression was positively associated with the risk of total CVD: the multivariable hazard ratio (95% confidence interval) was 1.27 (1.05–1.54). In contrast, no association was found among rural residents: the corresponding ratio (interval) was 0.96 (0.85–1.09), with a significant interaction between urban and rural residency with anger expression for incident CVD (p = .047). Similar associations were observed with the risk of CVD subtypes, including ischemic stroke and ischemic CVD.Conclusions We found a positive association between anger expression and the risk of CVD among urban residents but not rural residents, suggesting that urbanicity enhances the anger-CVD association