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.