Association of apo E polymorphism with variations in lipid and small dense LDL in Koreans with a low fat intake

We investigated whether apo E polymorphism contributes to the variations in blood lipid profile, apolipoprotein B and small dense LDL in 92 clinically healthy Korean subjects who traditionally consume a low fat and low cholesterol diet (40 males, 52 females, aged 24-60). Body weight, height, waist and hip circumference were measured. Body mass index (BMI) and waist to hip ratio (WHR) were calculated. Dietary intake was assessed by using a semi-quantitative Food Frequency Questionnaire. Alleles ε3, ε2 and ε4 showed relative frequencies of 72.8%, 7.6%, and 19.6%, respectively, in the subjects. In order to estimate the independent effects of alleles ε2 and ε4, as compared with ε3 homozygosity, on lipid and apolipoprotein parameters, multiple linear regression was performed after adjustment for confounding variables such as age, gender, BMI, WHR, smoking and alcohol consumption. Apo E polymorphism was associated with variations in the serum concentrations of LDL-cholesterol, apolipoprotein B and concentration of LDLIII (d 1.044 - 1.063 g/ml), and was higher in the allele ε4 than ε3 homozygosity. Moreover, the allele ε4 significantly increased the concentration of LDLIII even after adjustment for the serum concentration of triacylglycerol. The allele ε2 did not show any significant effects on lipid or apolipoprotein concentrations. Our results showed that the apo E4 isoform was related to higher levels of LDL-cholesterol and small dense LDL in Koreans who are exposed to a low fat, carbohydrate rich diet.