Relevance of apolipoprotein E4 for the lipid profile of Brazilian patients with coronary artery disease

Abstract

Apolipoprotein E ( apoE - epsilon 2, epsilon 3, epsilon 4 alleles) playsa role in the regulation of lipid metabolism, with the e4 considered tobe a risk factor for coronary artery disease ( CAD). We aimed toevaluate the apoE polymorphisms in Brazilians with CAD and theirinfluence on the lipid profile and other risk factors ( hypertension,diabetes mellitus, smoking). Two hundred individuals were examined: 100patients with atherosclerosis confirmed by coronary angiography and 100controls. Blood samples were drawn to determine apoE polymorphisms andlipid profile. As expected, the epsilon 3 allele was prevalent in theCAD ( 0.87) and non- CAD groups ( 0.81; P = 0.099), followed by the e4allele ( 0.09 and 0.14, respectively; P = 0.158). The epsilon 3/3 ( 76and 78%) and epsilon 3/4 ( 16 and 23%) were the most common genotypesfor patients and controls, respectively. The lipid profile was alteredin patients compared to controls ( P < 0.05), independently of the e4allele. However, in the controls this allele was prevalent inindividuals with elevated LDL-cholesterol levels only ( odds ratio =2.531; 95% CI = 1.028- 6.232). The frequency of risk factors was higherin the CAD group ( P < 0.05), but their association with the lipidprofile was not demonstrable in epsilon 4 carriers. In conclusion, theepsilon 4 allele is not associated with CAD or lipid profile in patientswith atherosclerosis. However, its frequency in the non- CAD group isassociated with increased levels of LDL- cholesterol, suggesting anindependent effect of the epsilon 4 allele on lipid profile when the lowfrequency of other risk factors in this group is taken into account.