Statistical analysis revealed that the GSTP1 polymorphism is significantly associated with the risk of developing T2DM (p = 0.05) but was not associated with the risk of developing DSPN in diabetic patients. GSTM1 and GSTT1 gene polymorphisms were associated with neither the risk of developing T2DM nor the risk of DSPN occurrence in diabetic patients. Here, GSTM1 is linked to type 2 diabetes mellitus.