Therefore, to further investigate the effects of the UCP1 -3826A/G, UCP2 -866G/A, UCP2 Ala55Val, UCP2 Ins/Del and UCP3 -55C/T polymorphisms on T2DM susceptibility, we conducted a meta-analysis of 22 published articles from different populations and also included the results from our case-control study. This evidence concerns the gene UCP2 and type 2 diabetes mellitus.