Association between interleukin-1β C (3953/4)T polymorphism and chronic periodontitis: evidence from a meta-analysis

The aim of this study was to perform a meta-analysis to evaluated the association between interleukin-1β (IL-1β) C(3953/4)T polymorphism and chronic periodontitis (CP). Systematic searches of electronic databases and hand searching of references were performed, including PubMed, Embase and Web of Science. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated. Publication bias was tested by Begg's funnel plot and Egger's regression test. Sensitivity analysis was conducted by limiting the meta-analysis studies conforming to Hardy-Weinberg equilibrium (HWE) or high quality (score ≥ 7). Data analyses were carried out by Stata 11.0. There were significant associations between IL-1β C(3953/4)T polymorphism and CP (for T allele vs. C allele: OR = 1.30, 95%CI = 1.05-1.60, p = 0.02; for T/T vs. C/C: OR = 1.66, 95%CI = 1.12-2.45, p = 0.01; for C/T+T/T vs. C/C: OR = 1.28, 95%CI = 0.99-1.65; and for T/T vs. C/T+C/C: OR = 1.62, 95%CI = 1.15-2.29, p = 0.006). When stratified by ethnicity, statistically significantly elevated risk was found for Caucasians, but not for Asians. When stratified by study design, evidences of significant association was observed between IL-1β C(3953/4)T polymorphism and CP in both population-based studies and hospital-based studies. This meta-analysis indicates that there is strong evidence for association between IL-1β C(3953/4)T polymorphism and CP.