Subarachnoid hemorrhage: a preventable disease with a heritable component.
OBJECTIVE
Subarachnoid hemorrhage (SAH) caused by ruptured intracranial aneurysm affects approximately 16 000 Americans annually, and almost 40% of affected patients die within 30 days despite the best current therapy. Prevention of SAH is therefore of paramount importance. We present a preliminary analysis of risk factors for SAH from our population-based, case-control study.


METHODS
Cases were prospectively collected and matched 2:1 by age, race, and gender to controls using random digit dialing. Personal risk factor history, family history, neuroimaging data, and genetic samples were obtained. Univariate and bivariate analyses were performed and population-attributable risks estimated. Multivariable analysis was performed using conditional logistic regression.


RESULTS
Between June 1997 and February 2000, 107 cases and 197 controls were enrolled. In bivariate analyses, a large proportion of population-attributable risk for SAH could be explained by modifiable risk factors: smoking, hypertension, and heavy alcohol use. In multivariable analysis, current cigarette smoking, history of hypertension, frequent alcohol use, lower body mass index, and a family history of a relative with SAH or intracranial aneurysm were found to be significant, independent risk factors for SAH.


CONCLUSIONS
Our data confirm previous reports that SAH clusters within some families independent of environmental risk factors, suggesting that SAH has a significant genetic component. Yet, even among families at increased risk of SAH, smoking cessation, treatment of hypertension, and reduced alcohol intake may substantially decrease SAH risk. The independent associations with heavy alcohol use and low body mass index with SAH may be confounded by smoking and require further study.
Kissela
Brett M
BM
Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0525, USA. kisselbm@uc.edu
Sauerbeck
Laura
L
Woo
Daniel
D
Khoury
Jane
J
Carrozzella
Janice
J
Pancioli
Arthur
A
Jauch
Edward
E
Moomaw
Charles J
CJ
Shukla
Rakesh
R
Gebel
James
J
Fontaine
Robert
R
Broderick
Joseph
J
D000437:Alcoholism / Q000453:epidemiology; D044383:Black People / Q000235:genetics; D015992:Body Mass Index; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007629:Kentucky / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D009820:Ohio / Q000453:epidemiology; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology* / Q000235:genetics / Q000517:prevention & control*; D044465:White People / Q000235:genetics; D000515:alpha 1-Antitrypsin / Q000235:genetics; D001741:Black or African American
D000515:alpha 1-Antitrypsin