The association between FTO polymorphisms and type 2 diabetes in Asian populations: A meta-analysis

Abstract Background An important condition for the management of diabetes mellitus is thorough understandings of its pathogenesis and risk factors, of which genetic factors play essential roles. Several variants of the FTO gene were reported as an obesity susceptibility factor. There have been a number of studies conducted in different Asian populations on various variants of the FTO gene with inconsistent results on the association with type 2 diabetes (T2D). The purpose of this study is to undertake a systematic review and meta-analysis to provide updated and comprehensive evidence regarding the associations between FTO gene polymorphisms and T2D risk in the Asian ethnic communities. Methods A systematic literature research of PubMed database and Cochrane Library was performed to identify eligible studies for pooled analyses. For each genetic polymorphism, odds ratios and their 95% confidence intervals were estimated under allelic model for each individual study. Pooled odds ratios were estimated using a random-effects model or a fixed-effect model depending on the heterogeneity among studies. Further, subgroup analyses by geographic region was also performed. Results Totally 40 studies with 81,727 subjects were included for analyses. The pooled analyses showed that four SNPs of the FTO gene (rs9939609, rs8050136, rs3751812 and rs7193144) were significantly associated with susceptibility to T2D in Asian populations, of which, the rs3751812 and rs7193144 were reported for the first time in a meta-analysis. The evidence strength varied among different geographic regions. Conclusions The results supported that certain variants of the FTO gene could be used to identify individuals at high risk of developing T2D in Asians populations.