Gender-specific effects of apolipoprotein E genotype on plasma lipid levels in a population-based sample of 6-7-year-old children in Spain

Aim: The effects of gender on the association between apolipoprotein E genotype and plasma lipid levels remain unclear in children. The aim of the present work was to evaluate these gender differences in a large population-based sample of 6-7-y-old children, free of the effects of sex hormones. Methods: Lipid levels and apo E genotypes were studied in a sample of 1255 (631 M, 624 F) Caucasian schoolchildren, aged 6-7 (mean age, 6.7) y in Spain. Results: A significant effect of the apo E genotype on plasma total cholesterol, LDL-C (low-density lipoprotein cholesterol) and apo B levels was observed. Taking the homozygous (epsilon)3(epsilon)3 genotype as reference, the presence of the (epsilon)2 and (epsilon)4 alleles is associated with substantially lower and higher plasma levels, respectively, of these variables. It was found that the effect of the apo E polymorphism on total cholesterol, LDL-C and particularly on apo B levels was greater in girls than in boys. Conclusion: At this prepubertal age, the influence of the apo E genotype on total cholesterol, LDL-C and apo B levels is more evident in girls than in boys. This difference in effect is not due to sex hormones. In our opinion, the earlier increase in adrenal androgens in girls than in boys at this age related to pubertal maturation could be responsible for these differences.