Interleukin-8 Gene -251 A/T (rs4073) Polymorphism and Coronary Artery Disease Risk: A Meta-Analysis

BACKGROUND Inflammation plays an important role in the pathogenesis of coronary artery disease (CAD). Studies have reported that inflammatory cytokine interleukin-8 (IL-8) gene -251 A/T (rs4073) polymorphism is correlated with CAD susceptibility, but the result remains controversial. The objective of this study was to clarify the association between IL-8 gene -251 A/T polymorphism and CAD risk. MATERIAL AND METHODS A meta-analysis included 8244 patients from 9 individual studies with 10 populations was conducted. Heterogeneity test was conducted, and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated used fixed-effect or random-effects model accordingly. Publication bias was evaluated with the Begg's funnel plot and Egger's test. Sensitivity analysis was also conducted. RESULTS A significant association between IL-8 gene -251 A/T polymorphism and CAD risk was found in the dominant model (OR 1.42, 95% CI 1.16-1.76, P<0.001), recessive model (OR 1.30, 95% CI 1.12-1.52, P<0.001), allelic model (OR 1.28, 95% CI 1.12-1.47, P<0.001), homozygote model (OR 1.59, 95% CI 1.21-2.08, P<0.001), and heterozygote model (OR 1.35, 95% CI 1.11-1.64, P=0.002). Subgroup analysis by ethnicity found significant associations in the Chinese population in the dominant model(OR 1.43, 95% CI 1.26-1.61, P<0.001), recessive model (OR 1.39, 95% CI 1.21-1.59, P<0.001), allelic model (OR 1.31, 95% CI 1.21-1.42, P<0.001), homozygote model (OR 1.66, 95% CI 1.41-1.95, P<0.001), and heterozygote model (OR 1.34, 95% CI 1.18-1.52, P<0.001), but no significant association was found in the Caucasian population. No significant publication bias was found. CONCLUSIONS The IL-8 gene -251 A/T polymorphism was significantly associated with CAD risk in the Chinese population but not in the Caucasian population, -251 A allele carrier had an increased risk of CAD in the Chinese population.