Predicting coronary heart disease in siblings--a multivariate assessment: the Framingham Heart Study.

The incidence of clinically recognized coronary heart disease and its relation to risk factors have been studied for 596 sibships in the Framingham Heart Study cohort. Only the 186 pairs of brothers were considered in the multivariate analysis, since the rate of coronary heart disease in women is low. Multiple logistic regression was performed by using endpoints of coronary heart disease as the dependent variable for the younger brother of the pair. Age, Metropolitan relative weight, systolic blood pressure, total cholesterol, cigarette smoking and endpoints of coronary heart disease for the older brother represent the independent variables. The incidence of myocardial infarction in the older brother is significantly related to myocardial infarction experience of the younger brother, even after the strong effects of total cholesterol, systolic blood pressure and cigarette smoking were controlled. These findings suggest that family history of myocardial infarction may be an important independent predictor of myocardial infarction, and suggest that familial aggregation for coronary heart disease may result from predisposition to disease, possibly genetic, that is not reflected in the measured levels of total cholesterol, systolic blood pressure or cigarette smoking.