Vitamin D receptor gene polymorphisms and the risk of the type 1 diabetes: a meta-analysis based on 40 case–control studies

Abstract

Objective The association between the vitamin D receptor ( VDR ) gene polymorphisms and the risk of Type 1 diabetes mellitus (T1DM) has been evaluated in several studies. However, the findings were inconclusive. Thus, we conducted a meta-analysis to comprehensively evaluate the effect of VDR gene polymorphisms on the risk of T1DM.Methods All relevant studies reporting the association between VDR gene polymorphisms and susceptibility to T1DM published up to July 2019 were identified by comprehensive systematic database search in web of science, Scopus, and PubMed. Strength of association were assessed by calculating of pooled odds ratios (ORs) and 95% confidence intervals (CIs). The methodological quality of each study was assessed according to the Newcastle–Ottawa Scale. Subgroup analysis stratified by ethnicity was also conducted.Results A total of 40 case–control studies were included in this meta-analysis. The results of overall population rejected any significant association between VDR gene polymorphisms and T1DM risk. However, the pooled results of subgroup analysis revealed significant negative and positive associations between FokI and BsmI genes polymorphism and T1DM in African and American populations, respectively.Conclusions This meta-analysis suggested a significant association between VDR gene polymorphism and T1DM susceptibility in ethnic-specific analysis.