Association between interleukin-35 polymorphisms and coronary heart disease in the Chinese Zhuang population: a case–control study

OBJECTIVESInflammatory cytokines play an important role in the pathogenesis of cardiovascular disease. Few studies have investigated the association between interleukin-35 (IL-35) genetic variants and the risk of coronary heart disease (CHD). We examined the association between IL-35 polymorphisms and CHD in the Chinese Zhuang population. PATIENTS AND METHODSA total of 707 CHD patients and 707 age-matched and sex-matched controls were enrolled in this case–control study. Genotypes of the single nucleotide polymorphisms (SNPs) of IL-35, including rs428253, rs6613, rs9807813, rs2243115, rs568408, rs582054, rs583911, rs4740, and rs393581, were examined by MassArray. Plasma IL-35 level was measured using an enzyme-linked immunosorbent assay. The multivariate logistic regression model was used to evaluate the association between the SNPs and the risk of CHD. RESULTSIn the Chinese Zhuang population, compared with the GG genotype of EBI3 rs428253, individuals with the CC genotype had a 2.02-fold (95% confidence interval1.07–3.84, P=0.031) higher risk of CHD. Further adjustment for potential risk factors did not alter the positive association (CC vs. GG, odds ratio=2.30, 95% confidence interval1.16–4.54, P=0.042). SNPs rs4740, rs2243115, rs568408, and rs582054 were not statistically related to the risk of CHD. The plasma IL-35 levels showed a marginally significant difference between rs428253 genotypes [GG13.39 (7.89–19.25) vs. CC+GC17.53 (8.98–22.56) pg/ml, P=0.057]. CONCLUSIONThe EBI3 rs428253 CC genotype was associated with an increased risk of CHD in the Chinese Zhuang population, although no significant difference in IL-35 levels was observed between genotypes in healthy controls.