Interleukin-6 Promoter Polymorphisms and Susceptibility to Atrial Fibrillation in Elderly Han Chinese Patients with Essential Hypertension

Abstract

There is an accumulating body of evidence indicating a strong association between inflammation and the pathogenesis of atrial fibrillation (AF). Interleukin-6 (IL-6) is a pleiotropic cytokine, functions as a mediator of inflammatory response, and has both proinflammatory and anti-inflammatory properties. The aim of the present study was to investigate the association of the −634C/G polymorphism of the IL-6 gene with AF in elderly Han Chinese patients with essential hypertension (EH). A total of 169 elderly patients with EH were eligible for this study. Patients with AF (n=75) were allocated to the AF group, and 94 subjects without AF to the control group. The polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) technique was used to assess the genotype frequencies. The distribution of the IL-6 −634C/G genotypes (CC, CG, and GG) was 67.02%, 30.85%, and 2.13% in the controls, and 50.67%, 40.00%, and 9.33% in AF subjects, respectively (P=0.0312). The frequency of the G allele in the AF group was significantly higher than that in the control group (29.33% vs. 17.55%, P=0.0103). Compared with the CC and CG genotypes, the GG homozygote had a 4.7353-fold increased risk of AF [95% confidence interval (CI)=0.9537–23.5116, P=0.0382]. These findings suggest that the IL-6 −634C/G polymorphism is associated with AF, and the G allele has increased risk of AF in elderly Han Chinese patients with EH.