Family history of coronary heart disease and pre-clinical carotid artery atherosclerosis in African Americans and whites: The ARIC study

The association between family history of coronary heart disease (CHD) and morbidity and mortality due to atherosclerotic sequelae, although well docu mented in population-based samples of whites, has been little studied in Af rican Americans. Less is known about the relationship between a family hist ory of CHD and pre-clinical atherosclerosis. We report the relation between family history of CHD, summarized in a family risk score (FRS), and asympt omatic atherosclerosis at the extracranial carotid arteries, measured by B- mode ultrasound. The FRS was assessed in relatives of 3,034 African America ns and 9,048 white probands aged 45 to 64 years, in the four community-base d cohorts of the ARIC Study. The analyses were restricted to individuals fr ee of clinically manifest CHD. The distribution of CHD FRS by ethnic-gender groups was right skewed, with slightly higher mean values for white than A frican-American males, and for African-American than white females. In a se ries of multivariate linear regression models with mean carotid artery inti ma-media wall thickness (IMT) as the dependent variable, FRS was associated positively with IMT in white and African-American women and white men. In a multiple regression model, approximately one-half of the quantitative sta tistical relationship of the CHD FRS with IMT in whites was statistically e xplained by the major risk factors considered as intervening, explanatory v ariables in this analysis. This association in African-American women was f ully explained by the major risk factors. The FRS was not, however, associa ted with atherosclerosis or major risk factors in African-American males, i n the ARIC Study. (C) 1999 Wiley-Liss, Inc.