Apolipoprotein E genotypes and their relation to lipid levels in a rural South African population

Genetic variation at the apolipoprotein E (apoE) locus is an important determinant of plasma lipids. The aim of the present study was to evaluate the association between apolipoprotein E genotype and plasma lipid levels among a rural black population in South Africa.

Lipid levels and apoE genotypes were studied in 505 volunteer subjects (363 women, 142 men) resident in the Dikgale demographic surveillance site.

Allele frequencies were found to be 0.190 for epsilon2, 0.518 for epsilon3, and 0.293 for epsilon4, indicating a relatively low frequency of the epsilon3 allele and a high frequency of the epsilon4 allele. To determine the effect of apoE polymorphism on lipid levels three groups were formed: namely epsilon2-, epsilon3-, and epsilon4-expressing groups. A significant effect of the apoE genotype on total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C)/Total cholesterol (TC) ratio, and triglycerides was observed. LDL-C was significantly lower and the HDL-C/TC ratio was significantly higher in the epsilon2 group compared with the epsilon3 and epsilon4 groups. Triglyceride levels were significantly higher in the epsilon2 group than in the epsilon3 group.

With the unfavourable apoE allele distribution, and the lifestyle changes taking place in rural South African populations, preventive strategies need to be developed to limit a potential epidemic of cardiovascular disease in the black population of South Africa.