Cigarette smoking and alcohol consumption as risk factors for aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE Aneurysmal subarachnoid hemorrhage is a serious disease despite recent improvements in medical and surgical treatment. Hence, identification of modifiable risk factors for subarachnoid hemorrhage is important. METHODS We compared the smoking and drinking habits of 278 consecutive patients with aneurysmal subarachnoid hemorrhage, aged 15-60 years (145 men and 133 women) with those of 314 hospitalized control patients (164 men and 150 women) who did not differ in regard to age, day of onset of symptoms, and acuteness of disease onset. RESULTS Multiple logistic regression analysis showed that recent alcohol intake and smoking, but not hypertension, were significant independent risk factors for hemorrhage. After adjustment for age, hypertension, and smoking status, men who had consumed 1-40, 41-120, or > 120 g of alcohol within the 24 hours preceding the onset of illness had a relative risk of hemorrhage of 0.3 (95% confidence interval [CI], 0.1-0.8), 2.5 (95% CI, 1.1-5.5), and 4.5 (95% CI, 1.5-12.9), respectively, compared with men who had consumed 0 g. Women who had consumed 1-40 or > 40 g of alcohol had a risk of hemorrhage of 0.4 (95% CI, 0.2-0.8) and 6.4 (95% CI, 2.3-17.9), respectively, compared with women without use of alcohol. Heavily smoking (> 20 cigarettes per day) men and currently smoking women had adjusted relative risks of hemorrhage of 7.3 (95% CI, 3.8-14.3) and 2.1 (95% CI, 1.2-3.6), respectively, compared with men who had never smoked and with women who were not current smokers. Higher levels of erythrocyte mean corpuscular volume in patients with subarachnoid hemorrhage than in control subjects supported the notion of different smoking and drinking habits. CONCLUSIONS Recent heavy alcohol intake and current smoking seem to be independent risk factors for aneurysmal subarachnoid hemorrhage.