The association between periodontitis and interleukin-6 genetic polymorphism -174 G/C: A meta-analysis.

BACKGROUND: To evaluate the association between periodontitis and interleukin-6 (IL6) -174 G/C polymorphism by data synthesis and subgroup analysis.

METHODS: Eighteen case-control studies from 16 articles with 1616 cases and 1511 controls were included in this meta-analysis by searching the public databases including PubMed, Embase and Web of Science databases by Jun 2018. Data syntheses were performed using Stata 9.0.

RESULTS: There were inverse associations of IL6 -174 G/C polymorphism with both general periodontitis and overall periodontitis. In CC vs. GG inheritance model, whose effect was the most profound, the genetic polymorphism reduced the risks of general and overall periodontitis by 60% (95% CI = 0.25-0.65, P <  0.01) and 31% (95% CI = 0.38-0.97, P =  0.04) respectively. In addition, the G/C variation was likely to be protective against moderate (allele C vs. allele G: OR = 0.61, 95% CI = 0.43-0.87, P =  0.01; CC + GC vs. GG: OR = 0.57, 95% CI = 0.37-0.89, P =  0.01) and severe periodontitis (allele C vs. allele G: OR = 0.58, 95% CI = 0.41-0.84, P <  0.01; CC vs. GG: OR = 0.33, 95% CI = 0.13-0.82, P =  0.02) exclusively in Brazilian people. No reliable evidence was found regarding chronic periodontitis.

CONCLUSION: This meta-analysis suggests that IL6 -174 G/C polymorphism may be negatively associated with risk of periodontitis.