[Alcohol intake and stroke in Eastern Asian men:a systemic review and meta-analysis of 17 prospective cohort studies].

OBJECTIVE: To assess the dose-response relationship between alcohol intake and relative risk of stroke and all-cause mortality among Eastern Asian men. METHODS: Potential prospective cohort studies were retrieved by searching Pubmed (1966 - 2000), OVID (1980 - 2009), Embase (1980 - 2009) and ISI Web of Knowledge (1986 - 2009) using Medical Subject Headings: alcohol drinking, ethanol, stroke, cerebrovascular disease, mortality, etc; and Koreans or Japanese or Chinese. From the relevant retrieved reports, 17 prospective cohort studies fulfilling the criteria were included into the study. Information on study design, participant characteristics, amount of alcohol intake, stroke and/or all-cause mortality outcomes, control for potential confounding factors and risk estimates was abstracted by a standardized protocol. For each study, relative risk (RR) and 95% confidence interval (CI) were extracted and pooled with either a fixed or random effect model according to the results of the test of heterogeneity. RESULTS: As data available for women were too limited to be included into our meta-analysis, this study focused on male subjects, ranging from 1322 to 108 461 subjects among these 17 cohort studies. Compared with nondrinkers, the RRs of ischemic stroke for those drinking alcohol ≤ 20, 21 - 40, 41 - 60, > 60 g/d, were 0.85 (0.78 - 0.93, P = 0.0002), 0.94 (0.79 - 1.11, P = 0.46), 1.08 (0.86 - 1.37, P = 0.50) and 1.24 (0.96 - 1.59, P = 0.10) respectively. Similarly, RRs of hemorrhagic stroke were 0.92 (0.75 - 1.12, P = 0.46), 1.11 (0.96 - 1.28, P = 0.17), 1.20 (0.92 - 1.56, P = 0.18) and 1.74 (1.32 - 2.28, P < 0.01); and those of all-cause mortality were 0.83 (0.75 - 0.91, P = 0.01), 0.93 (0.87 - 0.99, P = 0.03), 1.01 (0.95 - 1.07, P = 0.86) and 1.32 (1.29 - 1.36, P < 0.01) respectively. CONCLUSION: In Eastern Asian men, light alcohol intake (≤ 20 g/d) is associated with a lowered risk of ischemic stroke whereas heavy alcohol intake is associated with an elevated risk of stroke, particularly hemorrhagic stroke and all-cause mortality.