Interleukin-1α -899 (+4845) C→T polymorphism increases the risk of chronic periodontitis: evidence from a meta-analysis of 23 case-control studies.

Many epidemiological studies have indicated that interleukin-1α (IL-1α) -899 (+4845) C→T polymorphism increases the risk of chronic periodontitis (CP), whereas some studies have reported opposite results. Accordingly, the aim of this meta-analysis is to investigate the association of the IL-1α -899 (+4845) C→T polymorphism with CP. We searched the PubMed database up to May 1, 2013 and finally obtained 23 case-control studies. After data extraction, we performed meta-analysis using Comprehensive Meta-Analysis v2.2 software. The overall result based on the fixed-effect model showed that IL-1α -899 (+4845) C→T polymorphism was significantly associated with increased risk of CP: [odds ratio (OR)=1.29, 95% confidence interval (CI)=1.15-1.44, p<0.001] for T vs. C; (OR=1.59, 95%CI=1.22-2.07, p=0.0005) for TT vs. CC; (OR=1.30, 95% CI=1.12-1.51, p=0.0004) for CT vs. CC; and (OR=1.40, 95% CI=1.21-1.61, p<0.001) for (CT+TT) vs. CC; (OR=1.47, 95% CI=1.16-1.87, p=0.002) for TT vs. (CT+CC). Stratified analyses revealed that there was a significantly increased risk for Caucasians and Asians. In conclusion, current evidence showed that IL-1α -899 (+4845) C→T polymorphism probably increased the risk of CP.