GSTM1 and type 2 diabetes mellitus: This study revealed a strong association combination of GSTM1 and GSTT1 polymorphisms and T2DM susceptibility in overall analysis (model 2: OR = 2.28, 95% CI = 1.72–3.04; model 3: OR = 2.19, 95% CI = 1.64–2.93; model 4: OR = 1.41, 95% CI = 1.15–1.72; model 5: OR = 1.89, 95% CI = 1.06–1.33; model 6: OR = 1.75, 95% CI = 1.41–2.18, Table 4).