Cholesterol and saturated fat intake determine the effect of polymorphisms at ABCG5/ABCG8 genes on lipid levels in children

Abstract

PurposeAnalysis of mutations in genes of the cholesterol metabolic pathway has not completely explained the interindividual variability of blood cholesterol concentrations attributed to gene–nutrient interactions. Thus, we analyzed polymorphisms in the ABCG5 and ABCG8 genes, involved in the regulation of intestinal cholesterol absorption, with special interest in a potential interaction with diet to determine lipid levels. MethodsThe polymorphisms ABCG5 C1950G (Gln604Glu) and ABCG8 C1895T (Ala640Val) were determined by polymerase chain reaction and restriction analysis in 1227 healthy school children, aged 6 to 8 years. ResultsNo significant differences were found in blood lipid levels between subjects with different genotypes of the two analyzed polymorphisms. However, important differences appeared when separating subjects by their different lipid intake. The presence of the ABCG8 C1895T and ABCG5 C1950G polymorphisms was associated with different plasma total cholesterol, low-density lipoprotein cholesterol complex, and apolipoprotein B levels only in low-cholesterol consumers (significantly for the C1895T polymorphism), and among children within the lower tertile of saturated fat intake (significantly for the C1950G polymorphism). ConclusionPolymorphisms at the half-transporter ABCG5 and ABCG8 genes affect blood cholesterol concentrations in prepubertal children by influencing dietary responsiveness. This highly significant gene–nutrient interaction could explain the great individual differences in the plasma lipid response to cholesterol and fat intake.