Interleukin-1 beta and interleukin-6 gene polymorphism associations with angiographically assessed coronary artery disease in Brazilians

Abstract

The inflammatory process has been considered an important mediator for the development of atherosclerosis. Interleukin-1 beta (IL1B) is a precursor of interleukin-6 (IL6) in the acute phase of inflammatory response and their levels are elevated in patients with coronary artery disease. The aim of the present study was to further investigate the association of IL-1B and IL-6 gene polymorphisms and angiographically assessed coronary artery disease (CAD) in African- and Caucasian-Brazilians. This report analyzed the IL-1B-511C>T and IL-6-174G>C polymorphisms in 667 patients (253 African-Brazilians and 414 Caucasian-Brazilians) who underwent coronary angiography. Patients with a coronary obstructive lesion 50% presented a higher frequency of the IL-1B-511CC genotype (30.4%) compared to lesion-free individuals (16.5%, p=0.032) in African- but not in Caucasian-Brazilians. No significant genotype frequency difference was identified for the IL-6-174G>C polymorphism in either ethnic groups. However, after correction for other CAD risk factors using multivariate logistic regression, both the IL-1B-511CC [Odds ratio (OR)=2.3; p=0.019] and the IL-6-174GG (OR=2.0; p=0.028) genotypes were considered independent CAD risk predictors in African-Brazilians. This report shows that the IL-1B-511C>T and IL-6-174G>C polymorphisms were associated with CAD risk in African-Brazilians and no association was detected among Caucasian-Brazilians.