Cigarette Smoking and Risk of Subarachnoid Hemorrhage: Does Cessation of Smoking Really Help?
BACKGROUND AND PURPOSE: Smoking has been shown to increase the risk of subarachnoid hemorrhage (SAH). It remains unclear whether cessation of smoking decreases this risk. To address this issue, we performed a case control study examining the effect of smoking and other known risk factors for cerebrovascular disease on the risk of SAH. METHODS:We reviewed the medical records of all patients with a diagnosis of SAH (n=323) admitted to the Johns Hopkins University hospital between January 1990 and June 1997. Controls matched for age, sex, and ethnicity (n=969) were selected from the nationally representative sample of the Third National Health and Nutrition Examination Survey. We determined the independent association between smoking (present and previous) and various cerebrovascular risk factors and SAH using logistic regression analysis. RESULTS:Of 323 patients admitted with SAH (mean age 52.7±14 years; 93 were men), 149 (46%) were currently smoking and 125(39%) were previous smokers. In the multivariate analysis, both previous cigarette smoking (OR = 3.4; 95% CI, 2.3–5.1) and present cigarette smoking (OR = 2.0; 95% CI, 1.3–3.0) were significantly associated with SAH. Hypertension was also significantly associated with SAH (OR = 2.4; 95% CI, 1.8–3.3). CONCLUSION:Cigarette smoking increases the risk for SAH as suggested in previous studies. However, the increased risk persists even after cessation of cigarette smoking suggesting the importance of early abstinence from smoking.