Reciprocal effects of apolipoprotein E alleles (ε2 AND ε4) on plasma lipid levels in normolipidemic subjects

Abstract

A significantly lower frequency of the ε2 allele and a significantly higher frequency of the ε3 allele were found in the normolipidemic Japanese population than those in the normolipidemic Caucasian populations. We have compared plasma lipid variables among the apolipoprotein (apo) E phenotype groups and estimated the average effects of the three common alleles (ε2, ε3 and ε4) on plasma lipid levels in normolipidemic subjects. Plasma triglyceride (TG), very low density lipoprotein (VLDL)‐TG, VLDL‐cholesterol (C) and apo E levels were high in the apo E3/2 group, intermediate in the apo E3/3 group and low in the apo E4/3 group, whereas plasma total cholesterol (TC), low density lipoprotein (LDL)‐C and high density lipoprotein (HDL)‐C levels were low in the apo E3/2 group, intermediate in the apo E3/3 group and high in the apo E4/3 group. Furthermore, the ε2 allele had an effect to increase the TG, VLDL‐TG, VLDL‐C and apo E levels and decrease the TC, LDL‐C and HDL‐C levels, whereas the ε4 allele had an effect opposite to the el allele. These results indicate that the ε2 and ε4 alleles have the reciprocal effects on plasma lipid, lipoprotein and apo E levels.