Background: Family history of stroke (FHS) is associated with risk of stroke in middle-aged to elderly populations. However, few studies have examined this association in younger women or by stroke type. A population-based, case-control study was conducted to examine the association of FHS and risk of stroke in young women, and to determine whether the association is independent of other stroke risk factors.
Methods: Cases were women aged 18 to 44 years, with first, nonfatal ischemic (n =49) and hemorrhagic (n = 63) strokes in western Washington State in 1991 to 1995. Demographically similar community controls (n = 446) were identified through random-digit telephone dialing. Information on FHS in first-degree relatives (parents and siblings) and other risk factors was obtained through an interview. Person-years (P-Y) at risk of stroke for relatives of each subject were included in polytomous logistic regression models to adjust for family size. The analysis was conducted between 1999 and 2000.
Results: After adjustment for age and P-Y, FHS in first-degree relatives was significantly associated with an increased risk of hemorrhagic (odds ratio [OR]=2.6, 95% confidence interval [CI]=1.5-4.3) and ischemic stroke (OR=2.1, 95% CI=1.2-3.9). FHS remained associated with risk of hemorrhagic stroke (OR=2.4, 95% CI=1.4-4.1) and ischemic stroke (OR=1.8, 95%CI=0.9-3.5) after further adjustment for diabetes, hypertension, hypercholesterolemia, body mass index, physical activity, smoking, alcohol, and family history of myocardial infarction. Findings were similar when associations with parental and sibling FHS were examined separately.
Conclusions: Family history of stroke is a risk factor for both hemorrhagic and ischemic strokes among young women.