Association of interleukin-1β -511C/T promoter polymorphism with COPD risk: a meta-analysis

Studies examining the role of interleukin (IL)-1β -511C/T promoter polymorphism in the pathogenesis of chronic obstructive pulmonary disease (COPD) have shown inconsistent results. This meta-analysis was performed to assess the association between the IL-1β-511C/T promoter polymorphism and COPD susceptibility. Published case-control, cross-sectional, and cohort studies from Pubmed, Embase, and China National Knowledge Infrastructure databases were retrieved. Data were extracted and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Twelve studies with 1692 cases and 2009 controls were included in this meta-analysis. Pooled effect size showed an overall but not significantly decreased risk of IL-1β-511 C/T with COPD susceptibility (OR = 0.89, 95%CI = 0.78-1.01) in a complete overdominant genetic model (TT+CC vs CT), indicating that homozygous individuals (CC and TT) have a decreased risk for COPD compared with heterozygotes (CT). In subgroup analysis by ethnicity, IL-1β-511C/T was significantly correlated with a decreased risk of COPD in Asians (OR = 0.73, 95%CI = 0.60-0.88, P = 0.001), but not in Caucasians (OR = 1.02, 95%CI = 0.83- 1.24, P = 0.46), confirming a protective role of IL-1β-511C/T in COPD in Asians. Moreover, after excluding studies that included populations not in Hardy-Weinberg equilibrium, the pooled results were robust and no publication bias was observed. This meta-analysis suggests that the IL-1β-511C/T promoter polymorphism deceases the risk of COPD in Asians.