Association of polymorphisms G(-174)C in IL-6 gene and G(-1082)A in IL-10 gene with traditional cardiovascular risk factors in patients with coronary artery disease

Interleukin-6 (IL-6) polymorphism has been associated with the genetic susceptibility to coronary artery disease (CAD) and also with the lipid profile in different populations. The present work aimed at studying the association, if any between the IL-6 (174) G/C and IL-10 (1082) G/A genes with hypertension or hyperlipidimia in Egyptian patients with CAD and the association of the EL-6 -174 G/C polymorphism with serum IL-6 levels. 108 Egyptian patients with CAD and 143 unrelated healthy subjects were included in the study. The different genotypes of IL-6 and IL-10 were detected by polymerase chain reaction. Serum levels of lipoprotein(a) [Lp(a)] and IL-6 were estimated in the patients, as well as in the healthy subjects. Increased frequency of G allele, GG and GC genotypes in IL-6, as well as decreased frequency of C allele and CC genotype were found in CAD patients, compared to healthy subjects [P = < 0.0001, OR = 3.95, 95% CI (2.16-7.22) for GG and GC vs CC genotype], [P = < 0.0001, OR = 3.44, 95% CI (2.26-5.23) for G allele]. There was an increased frequency of G allele vs A allele in IL-10 genotype in CAD patients, compared to healthy subjects [P = 0.005, OR = 1.866, 95% CI (1.2-2.9]. Higher levels of both Lp(a) and IL-6 were observed in CAD patients, compared to control subjects (P = 0.0012, P = 0.0346, respectively). Increased frequency of IL-6 -174 G-allele was implicated in a greater cardiovascular risk and the presence of G allele or homozygosity for G allele of IL-10 G/A (1082) was associated with an increased prevalence of CAD. The GC genotype and G allele in IL-6 had significant correlation with hyperlipidimic CAD patients; however, G allele in IL-6 and IL-10 showed significant association with hypertension. Thus, G allele in IL-6 and IL-10 was considered as an independent risk factor in hypertensive CAD patients.