Background: The purpose of the meta-analysis is to explore the association between vitamin D receptor polymorphisms (including four gene loci: Taq-I, Bsm-I, Apa-I, and Fok-I) for susceptibility to periodontitis (either chronic [CP] or aggressive [AP]). Up to now, there has been only one systematic review focusing on this topic. We obtained some different findings compared with the previously published literature.
Methods: Nineteen case-control studies were identified through a search of multiple electronic databases (from January 1, 1999 to June 30, 2011). The pooled odds ratios (ORs) and 95% confidence intervals (CIs) using codominant, dominant, and recessive genetic models from meta-analysis were the main outcome measure. The Harbord test was used to detect the publication bias for each group.
Results: Eighteen identified articles met the eligibility criteria. Through overall analyses, no statistical association was found between polymorphisms of the four gene loci and periodontitis. However, based on subgroup analyses, a significant association between the Taq-I variants and CP rather than AP was shown in Asians (OR = 0.590; 95% CI = 0.425, 0.818) but not in whites (OR = 0.823; 95% CI = 0.637, 1.063). No statistically significant association was found between polymorphisms of Bsm-I and Apa-I with either AP or CP. The Fok-I polymorphism showed a statistical association with AP (OR = 1.583; 95% CI = 1.157, 2.166) instead of CP (OR = 1.081; 95% CI = 0.638, 1.830) in Asians.
Conclusions: The results of the present meta-analysis indicate the following: 1) the mutant allele t of the Taq-I locus may be a protective factor for CP but not for AP in Asians, although this was not true in whites; 2) the mutant allele F of the Fok-I locus appeared to be a risk factor for AP rather than CP in Asians; and 3) Bsm-I and Apa-I polymorphisms were found to have no significant associations with susceptibility to periodontitis (CP/AP).