Smoking and the risk of hemorrhagic stroke in men.
OBJECTIVE
Smoking is an established risk factor for ischemic stroke and subarachnoid hemorrhage (SAH), but the impact of smoking on intracerebral hemorrhage (ICH) is less clear.


METHODS
Prospective cohort study among 22,022 US male physicians participating in the Physicians' Health Study. Incidence of stroke was measured by self-report and confirmed by medical record review. We used Cox proportional-hazards models to evaluate the association of smoking with risk of total hemorrhagic stroke, ICH, and SAH. We categorized smoking into 4 groups: never, past, or current smokers of <20 or of >or=20 cigarettes per day.


RESULTS
During 17.8 years of follow-up, 108 ICHs and 31 SAHs occurred. Never smokers and past smokers had equal rates of ICH and SAH. Current smokers of <20 cigarettes per day had multivariable-adjusted relative risks of 1.65 (95% CI, 0.61 to 4.50) for total hemorrhagic stroke, 1.60 (95% CI, 0.50 to 5.07) for ICH, and 1.75 (95% CI, 0.24 to 13.09) for SAH when compared with never smokers. Current smokers of >or=20 cigarettes had relative risks of 2.36 (95% CI, 1.38 to 4.02) for total hemorrhagic stroke, 2.06 (95% CI, 1.08 to 3.96) for ICH, and 3.22 (95% CI, 1.26 to 8.18) for SAH when compared with never smokers.


CONCLUSIONS
This prospective study suggests an increased risk of total hemorrhagic stroke, ICH, and SAH in current cigarette smokers with a graded increase in risk that depended on how many cigarettes were smoked. The effect of smoking on ICH is of about the same magnitude as the effect of smoking on ischemic stroke. Our results add to the multiple health benefits that can be accrued by abstaining from cigarette smoking.
Kurth
Tobias
T
Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02215-1204, USA. tkurth@rics.bwh.harvard.edu
Kase
Carlos S
CS
Berger
Klaus
K
Schaeffner
Elke S
ES
Buring
Julie E
JE
Gaziano
J Michael
JM
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology; D001241:Aspirin / Q000627:therapeutic use; D015992:Body Mass Index; D002545:Brain Ischemia / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002536:Cerebral Arteries / Q000187:drug effects / Q000473:pathology; D002543:Cerebral Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D003920:Diabetes Mellitus / Q000453:epidemiology; D015444:Exercise; D005500:Follow-Up Studies; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008499:Medical Records / Q000706:statistics & numerical data; D008875:Middle Aged; D015999:Multivariate Analysis; D009369:Neoplasms / Q000517:prevention & control; D010820:Physicians / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology / Q000209:etiology; D014481:United States / Q000453:epidemiology; D019207:beta Carotene / Q000627:therapeutic use
D019207:beta Carotene; D001241:Aspirin