ASSOCIATION BETWEEN SERUM-LIPIDS AND APOLIPOPROTEIN-E PHENOTYPE IS INFLUENCED BY DIET IN A POPULATION-BASED SAMPLE OF FREE-LIVING CHILDREN AND YOUNG-ADULTS - THE CARDIOVASCULAR RISK IN YOUNG FINNS STUDY

Apolipoprotein E (apoE) is a genetic determinant of coronary heart dis ease and lipid levels in several populations. We studied whether the a ssociation of apoE alleles with serum lipids varies with diet in a pop ulation of free-living young Finns. One thousand twelve subjects, aged 9-24 years, were studied as a part of the Cardiovascular Risk in Youn g Finns Study in 1986. Serum lipid concentrations and apoE phenotypes were determined, and the composition of the diet was assessed by the 4 8-h recall method. The subjects were divided into three groups accordi ng to the intake of dietary saturated fatty acids (SAFA, g/1000 kcal) and cholesterol (mg/1000 kcal). Group one (high SAFA-cholesterol group ) was formed from subjects belonging to the highest tertiles of both c holesterol and SAFA intakes (n = 175); group two (middle SAFA-choleste rol group) consisted of subjects belonging to the middle respective te rtiles (n = 119); and group three (low SAFA-cholesterol group) consist ed of subjects belonging to the lowest respective tertiles (n = 192). The statistical significance of the association of serum total cholest erol and low density lipoprotein (LDL) concentration with apoE phenoty pe increased from the low SAFA-cholesterol group (P = 0.024 for total cholesterol and P = 0.015 for LDL-cholesterol, respectively) to the hi gh SAFA-cholesterol group (P = 0.0022 and P = 0.00073, respectively). The middle SAFA-cholesterol group fell between these two groups. The a verage serum cholesterol lowering effect of the epsilon 2 allele in th e low, middle, and high SAFA-cholesterol groups was; -0.22 mmol/l, -0. 33 mmol/l, and -0.52 mmol/l, respectively, while the epsilon 4 allele raised these levels by +0.27, +0.36, +0.52 mmol/l, respectively. The r esults for serum LDL-cholesterol were parallel to those of serum total cholesterol. The average effect of the epsilon 2 allele on serum trig lyceride was to raise its level in the subject belonging to low SAFA-c holesterol group only (P = 0.0008). The average effects of the epsilon 2 and epsilon 4 alleles on serum high density lipoprotein (HDL) chole sterol were to raise its concentration in the high SAFA-cholesterol gr oup only (P = 0.013). Our results suggest that the effect of the apoE allele on serum total cholesterol, LDL-cholesterol, HDL-cholesterol, a nd triglyceride is influenced by diet and provides further evidence th at this is also true among free-living subjects consuming their ordina ry diet.