In addition, the plasma XOR activity showed significant positive correlations with the AST (R = 0.81, P < 0.001), ALT (R = 0.88, P < 0.001), γ-GTP (R = 0.76, P < 0.001), and triglyceride (TG) (R = 0.32, P < 0.01), and negative correlations with the percent glycated albumin (R = − 0.27, P = 0.01) and HDL-C (R = − 0.30, P < 0.05); no significant correlation of the plasma XOR activity with the HbA1c (R = 0.08, P = 0.43) or the fasting plasma glucose level (R = 0.00, P = 0.98) was observed in the patients with type 2 diabetes. Here, GPT is linked to type 2 diabetes mellitus.