Association between TNF-α G-308A (rs1800629) polymorphism and susceptibility to chronic periodontitis and type 2 diabetes mellitus: A meta-analysis

Background and objective Although the association between tumor necrosis factor-alpha (TNF-alpha) G-308A (rs1800629) polymorphism and chronic periodontitis (CP), chronic periodontitis with type 2 diabetes mellitus (DP) is assumed, results of this association have been contradictory. The aim of this study was to assess the relationship between rs1800629 polymorphism and CP/DP susceptibility. Methods We searched for studies on PubMed, Web of Science, MEDLINE, Chinese National Infrastructure, and WanFang databases. Study selection was performed using specific inclusion and exclusion criteria and fulfilled the PECO (participant, exposure, comparison, and outcome) format. The relationship between rs1800629 polymorphism and CP/DP susceptibility was evaluated by the effect summary odds ratio (OR) and 95% confidence intervals (CIs). Allele, dominant, and recessive genetic models were computed to assess the strength of the association. Results A total of 25 case-control studies were included in the analysis. In the Asian population, TNF-alpha rs1800629 polymorphism was found to be significantly associated with CP in the overall analyses and for all genetic contrasts, while no significant risks were found among Caucasian populations for all genetic contrasts. The TNF-alpha rs1800629 polymorphism was also associated with increased DP risk in Asians under the fixed-effects model, but not in the recessive comparison. Conclusion The meta-analysis suggested that TNF-alpha rs1800629 polymorphism might affect the risk of CP and DP, particularly in individuals of Asian descent.