Family history and risk for ischemic stroke: Sibling history is more strongly correlated with the disease than parental history

Current data concerning the association between family history and the risk for developing stroke have been controversial. There has been very little data on the influence of family history on intracranial atherosclerosis (ICAS), stroke severity, and recovery, especially among Asian populations. We evaluated the association between family history and the risk for stroke and investigated the relationships between family history and ICAS, stroke severity, and short-term stroke outcome in Korean stroke patients. In this case-control study, we recruited 400 patients with acute ischemic stroke, along with the same number of age- and gender-matched control subjects. Assessments of first-degree family history of stroke, myocardial infarction, hypertension and diabetes mellitus were obtained by structured questionnaires, followed by reviews of the clinical and neuro-radiological findings of the stroke patients. A family history of stroke was associated with an increased risk of ischemic stroke (OR, 2.65; 95% CI, 1.75 to 4.01), and the correlation remained significant after multivariate analysis. The odds ratios of paternal, maternal, and sibling history were 2.07, 2.16, and 4.21, respectively. The risk of stroke did not differ significantly with the presence of ICAS, stroke severity, and stroke outcome. Family history of stroke was an independent risk factor for ischemic stroke. A positive sibling history was more strongly correlated with the incidence of stroke than a positive parental history, and this finding may indicate the possible role of environmental factors in a shared household in addition to the genetic factors involved in family medical history.