Apolipoprotein E polymorphism--a risk factor for metabolic syndrome.

Background: Metabolic syndrome is closely related to several disturbances in lipid and lipoprotein metabolism. The aim of this study was to determine the association between apolipoprotein E (apoE) genotypes and the risk of metabolic syndrome and/or coronary heart disease complications.

Methods: The study included 279 subjects divided into three groups: 1) control subjects, 2) metabolic syndrome patients, and 3) obese patients with coronary heart disease. All subjects were characterized by body mass index, and plasma levels of glucose, triglycerides, cholesterol, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). ApoE genotypes were identified by PCR-restriction fragment length polymorphism using genomic DNA.

Results: Statistical analysis of plasma parameters showed that subjects in groups 2 and 3 had higher levels of triglycerides and lower levels of HDL-C compared to group 1. The frequencies of apoE genotypes determined in this Romanian population (65% for E3/3, 19.6% for E4/3, 9.5% for E3/2, 4.1% for E2/2, 0.6% for E4/4, 1.3% for E4/2) were in agreement with those reported for other Caucasian populations. The distribution of apoE alleles indicated a higher frequency of epsilon4 in groups 2 and 3. There was a higher frequency of the apoE4/3 genotype in groups 2 and 3, which was significantly correlated with higher levels of triglycerides and lower levels of HDL-C.

Conclusions: Correlations of apoE genotypes with these markers indicate that the epsilon4 allele is an independent risk factor for metabolic syndrome.