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.

The role of serum uric acid as a predictor of stroke remained controversial among general Japanese population. We conducted a prospective cohort study of 5235 men and 8185 women residents aged 40-79 years at baseline between 1985 and 1994, initially free from stroke, coronary heart disease and under medication for hyperuricemia or gout, in four Japanese communities. Cox proportional hazards models were used to estimate sex-specific hazard ratios of stroke and its types in relation to serum uric acid levels. During a median follow-up of 23.1 years, we determined 1018 (488 men and 530 women) incident stroke, 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) for the highest versus lowest quintiles 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

ObjectiveTo assess the association between low serum creatinine levels and an increased risk of type 2 diabetes mellitus and dysglycemia.Research design and methodsWe conducted a retrospective cohort study of 3313 Japanese male workers aged 30–55 years, who underwent annual health check-ups during 2001–2008 and showed no type 2 diabetes mellitus, and underwent follow-up examinations until March 2013. Dysglycemia was defined as a fasting plasma glucose concentration of ≥110 mg/dL (6.1 mmol/L), or a non-fasting plasma glucose concentration of ≥140 mg/dL (7.8 mmol/L). A Cox proportional model was used to calculate HRs and 95% CIs for developing type 2 diabetes mellitus or dysglycemia.ResultsDuring the median 6.7-year follow-up, there were 207 cases of incident type 2 diabetes mellitus and 596 cases of incident dysglycemia, including 115 cases of type 2 diabetes mellitus among the subjects with normal glucose concentrations at baseline. After adjustment for age, body mass index and known diabetes risk factors, the multivariable HR of type 2 diabetes mellitus for the lowest category of serum creatinine (<0.7 mg/dL) vs the highest category (0.9–1.1 mg/dL) was 1.9 (95% CI 1.2 to 2.9; P for trend 0.03). The multivariable HRs of dysglycemia for the lowest category of serum creatinine versus the highest category was 1.5 (95% CI 1.1 to 1.9; P for trend 0.01).ConclusionsLow serum creatinine levels were associated with an increased risk of type 2 diabetes mellitus and dysglycemia.

Aims: Smoking impairs endothelial function as an acute effect. However, few population-based studies have examined the association between smoking status and endothelial function or the dose-response and duration- response association of smoking with endothelial function. We examined whether smoking habits were associated with impaired endothelial function depending on smoking dose and duration.Methods: We conducted a cross-sectional study of 910 men and women aged 30–79 years from 2013 to 2016. Statistical analyses of the data were conducted between 2016 and 2017. Endothelial function was assessed by brachial artery flow-mediated dilation (FMD) measurement. Low FMD was defined in two ways as the cutoff point based on the lowest quartile of %FMD (< 5.1%) and median of %FMD (< 6.8%), regarding as impaired endothelial function. We investigated the smoking status in terms of cigarettes consumed per day and the duration of smoking.Results: Heavy and chronic smokers were associated with a high prevalence of impaired endothelial function. Those associations did not change substantially after adjustment for other cardiovascular risk factors. Among all participants, the multivariable-adjusted ORs (95% CIs) of low FMD (< 5.1%) with reference to never smokers were 2.23 (1.00–5.14) for current heavy smokers of ≥ 30 cigarettes per day, 1.83 (1.04–3.20) for heavy smokers of ≥ 40 pack-years, and 2.16 (1.15–4.06) for chronic smokers of ≥ 40 years. For low FMD (< 6.8%) those values was 2.17 (1.01–5.05), 1.70 (1.01–2.86), and 1.98 (1.07–3.69), respectively.Conclusions: Similar associations were observed among only men. Heavy or long-term tobacco smoking may induce impaired endothelial function.