Apolipoprotein E polymorphism and its relation to plasma lipids in coronary heart disease.

BACKGROUND The present investigation is aimed at examining the Apolipoprotein E (APOE) genotypic influence on coronary heart disease (CHD) risk in northwest India (Punjab), where this disease is emerging as a major threat to public-health care system. MATERIALS AND METHODS The present study comprised of angiographically diagnosed coronary heart disease patients (n = 193) and controls (n = 150) of Punjab. Genetic polymorphism of APOE gene was investigated by polymerase chain reaction (PCR), and its association with lipid levels was evaluated. RESULTS The allele frequencies of epsilon2, epsilon3, and epsilon4 were 0.054, 0.795, 0.151; and 0.077, 0.856, 0.067 in patients and controls respectively. The bearers of E3/E4 genotype had threefold higher propensity of developing CHD in this population (OR, 3.04; CI, 1.55-6.25; P < 0.001), which exacerbated (OR, 4.18; CI, 2.03-9.27; P < 0.001) after correcting for age, sex, BMI, and lipid-lowering drugs. Lower HDL-C levels and higher LDL-C levels were found to be correlated with E3/E4 genotype (P < 0.01). Other concomitants like body mass index (BMI), total cholesterol (TC), and triglyceride (TG) levels did not show up as genetic determinants in this part of the region. CONCLUSIONS A significant association (P = 0.016) of epsilon4 allele, especially E3/E4 genotype, with CHD was observed, along with HDL-C and LDL-C concentrations, in the population of northwest India.