Prospective study on alcohol intake and risk of subarachnoid hemorrhage among Japanese men and women

Background: Few prospective data are available to evaluate potential risk f actors of subarachnoid hemorrhage among the Japanese, although several pros pective studies conducted in the United States and in Europe have shown a p ositive relationship between alcohol intake and the risk of subarachnoid he morrhage. Methods: A 9.4 year follow-up study was conducted on 12,372 men and women a ge 40 to 69 years who had no history of stroke, in six communities in Japan . The incident cases of subarachnoid hemorrhage were confirmed with compute d tomography findings and/or clinical findings. Alcohol intake and other ce rebrovascular risk factors were measured at the baseline examination. A Cox proportional hazard analysis was used to estimate the relative risks and 9 5% confidence intervals of the incidence of subarachnoid hemorrhage. Results: During the follow-up assessment, 71 cases of subarachnoid hemorrha ges occurred. For men, heavy drinking appeared to be an independent risk fa ctor for subarachnoid hemorrhage; multivariate-adjusted relative risk was 4 .3 (95% confidence interval [CI]: 1.1-16.8;p = 0.04). Among women, no exces s risk was found for heavy drinking, probably due to the small number of he avy drinkers (n = 15). The combination of heavy drinking with smoking or hy pertension increased the risk of subarachnoid hemorrhage substantially for men; the multivariate-adjusted relative risk was 6.0 (95% CI: 1.8-20.1;p = 0.004) for heavy drinking smokers and 13.0 (95% CI: 3.9-43.9;p < 0.001) for heavy drinking hypertensives. Conclusions: A reduction in alcohol intake, smoking cessation, and control of hypertension are important in preventing subarachnoid hemorrhage among J apanese men.