Association of APOE gene polymorphism with lipid profile and coronary artery disease in Afro-Caribbeans

Objectives Apolipoprotein E gene (APOE) polymorphism is associated with the lipid profile and cardiovascular disease. However, these relationships vary between ethnic groups. We evaluated, for the first time in an Afro-Caribbean population, the distribution of APOE polymorphisms and their associations with coronary artery disease (CAD), the lipid profile and other cardio-metabolic risk factors. Methods We studied 712 Afro-Caribbean subjects including 220 with documented CAD and 492 healthy subjects. TaqMan assays were performed to genotype rs7412 and rs429358, the two variants that determine the APOE alleles epsilon 2, epsilon 3 and epsilon 4. The association between APOE genotype and the lipid profile was analysed by comparing epsilon 2 carriers, epsilon 3 homozygotes and epsilon 4 carriers. Results The frequencies of epsilon 2, epsilon 3 and epsilon 4 in the overall sample were 8%, 70% and 22%, respectively. CAD was not associated with APOE polymorphism. The total cholesterol level was higher in epsilon 4 carriers compared with epsilon 2 carriers: 5.07 vs 4.59 mmol/L (P = 0.016). The LDL-cholesterol level was lower in APOE epsilon 2 carriers compared with epsilon 3 homozygotes and epsilon 4 carriers: 2.65 vs 3.03 and 3.17 mmol/L, respectively (p = 0.002). The total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios were similar in the three allelic groups. APOE polymorphism was not associated with diabetes, hypertension, waist circumference or body mass index. Conclusions Our results indicate that APOE gene polymorphism is associated with the lipid profile but not with CAD in Afro-Caribbean people. This lack of association with CAD may be explained by the low atherogenic profile observed in epsilon 4 carriers, which may warrant further investigation.