Active and Passive Smoking and the Risk of Subarachnoid Hemorrhage

Abstract

Background and Purpose-This study was undertaken to better clarify the risks associated with cigarette smoking and subarachnoid hemorrhage (SAH). Methods-The study included 432 incident cases of SAH frequency matched to 473 community SAH-free controls to determine dose-dependent associations of active and passive smoking (at home) and smoking cessation with SAH. Results-Compared with never smokers not exposed to passive smoking, the adjusted odds ratio for SAH among current smokers was 5.0 (95% confidence interval [CI], 3.1 to 8.1); for past smokers, 1.2 (95% CI, 0.8 to 2.0); and for passive smokers, 0.9 (95% CI, 0.6 to 1.5). Current and lifetime exposures showed a clear dose-dependent effect, and risks appeared more prominent in women and for aneurysmal SAH. Approximately 1 in 3 cases of SAH could be attributed to current smoking, but risks decline quickly after smoking cessation, even among heavy smokers. Conclusions-A strong positive association was found between cigarette smoking and SAH, especially for aneurysmal SAH and women, which is virtually eliminated within a few years of smoking cessation. Large opportunities exist for preventing SAH through smoking avoidance and cessation programs.

Risk Factors for Subarachnoid Hemorrhage

“…Most longitudinal studies were initiated in the 1970s and were restricted to the US, Japanese, UK, Korean, and Finnish populations. Of the 23 case-control studies, 10 (63% of SAH cases) [12][13][14][15][16][17][18][19][20][21] were population based and 13 hospital based, [22][23][24][25][26][27][28][29][30][31][32][33][34] covering a variety of populations: American (United States), Latin American (Chile, Colombia, Mexico, Brazil, and Jamaica), European (Norway, Germany, Hungary, Portugal, Denmark, Yugoslavia, Slovenia, Finland, and the United Kingdom), African (Kenya, Zambia, and Zimbabwe), and Australasian (China, Indonesia, Thailand, Australia, New Zealand, and Japan). Overall, 3936 cases of SAH (892 cases in longitudinal studies [9 223 763 person-years of follow-up] and 3044 cases in case-control studies) were available for the analysis, thus allowing 1984 more cases of SAH to be analyzed than in the previous overview.…”

“…Our finding that most risk factors tend to be more hazardous in women than in men, although this difference is statistically nonsignificant, suggests that this may contribute to the higher incidence of SAH observed in women. Case-control 12,14,22,24,26,27 0.7 (0.5-0.8) †Totals represent pooled estimates for all available studies reporting data for both men and women separately or combined; there were a different No. of studies that contributed data to the overall effect estimates and No.…”

Epidemiology of Traumatic Brain Injury and Subarachnoid Hemorrhage

“…Anderson and the Australasian Cooperative Research on Subarachnoid Hemorrhage Study (ACROSS) Group [24] found a strong positive association between cigarette smoking and SAH, especially for aneurysmal SAH and women, which is virtually eliminated within a few years of smoking cessation. Among patients in Izumo (Japan), hypertension was the most notable risk factor for aneurysmal SAH, regardless of age and sex, followed by cigarette smoking in younger men and hypercholesterolemia in older women.…”

Transdermal Nicotine Replacement Therapy in Cigarette Smokers with Acute Subarachnoid Hemorrhage

“…Smoking is an important risk factor for aneurysmal subarachnoid hemorrhage (SAH), and 40-60% of all patients admitted with spontaneous SAH are active cigarette smokers [1][2][3]. Being an active smoker at the time of hospital admission for SAH is a risk factor for the development of delayed cerebral ischemia (DCI) from vasospasm [2,4,5].…”