Five published meta-analyses (Tang et al., 2013; Yi et al., 2013; Zhang et al., 2013; Saadat, 2017; Nath et al., 2019) reported the GSTM1, GSTT1 and GSTP1 IIe105Val polymorphisms with T2DM risk. This evidence concerns the gene GSTP1 and type 2 diabetes mellitus.