Associations between vitamin D receptor genetic variants and periodontitis: a meta-analysis

Objective: Numerous studies already investigated potential associations between vitamin D receptor (VDR) genetic variants and periodontitis. However, the results of these studies were not consistent. Previous studies failed to reach a consensus regarding associations between VDR variants and periodontitis partially because of their relatively small sample sizes. Thus, we performed the present meta-analysis to explore the relationship between VDR variants and periodontitis in a larger pooled sample size. Material and methods: Systematic literature research was conducted in PubMed, Web of Science, Embase and CNKI to identify eligible case-control studies on associations between VDR variants and periodontitis. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the strength of associations in all possible genetic models, and p values <=.05 were considered to be statistically significant. Results: Totally 30 studies were enrolled for analyses. Pooled analyses suggested that VDR rs2228570 variant was significantly associated with the susceptibility to periodontitis under dominant genetic model in the overall population (p = .03, OR = 0.82, 95%CI: 0.69-0.98, I-2 = 0). Further subgroup analyses yielded similar positive results for rs2228570 variant in East Asians and patients with chronic periodontitis. Nevertheless, no any other positive findings were observed in overall and subgroup analyses. Conclusions: Our meta-analysis supported that VDR rs2228570 variant might serve as a genetic biomarker of periodontitis. However, further well-designed studies are still warranted to confirm our findings.