QUANTITATIVE EFFECTS OF THE APOLIPOPROTEIN-E POLYMORPHISM IN A BIRACIAL SAMPLE OF 9-10-YEAR-OLD GIRLS

Genetic polymorphism at the apolipoprotein E locus (APOE) has been sho wn to have a significant impact on quantitative risk factors for coron ary artery disease (CAD) in diverse populations. However, despite the recognition that atherosclerosis begins in childhood and that genetic factors are related to the initial stages of atherosclerosis, prior st udies were carried out mostly on adults and little attention has been paid to genetic risk factors for CAD in children. We have examined the impact of APOE polymorphism on quantitative risk factors for CAD (apo AI, apoB, TC, LDL-C, HDL-C and TG) in a sample of 647 African American and 573 White 9-10-year-old girls who were enrolled in the National H eart, Lung and Blood Institute Growth and Healthy Study. The frequenci es of the APOE2, APOE*3 and APOE*4 alleles were 0.09, 0.76 and 0.15 i n Whites and 0.11, 0.70 and 0.19 in African Americans, respectively. T he APOE2 allele was significantly associated with lower mean levels o f LDL-C and apoB and the APOE4 allele with higher levels of LDL-C and apoB in both racial groups. Variation in maturation stage, body fat a nd fat patterning, as assessed by skin fold measures and waist/hip rat io, accounted for a significant proportion of the variation in quantit ative CAD risk factors.