Increased plasma DPP4 activity was associated with higher circulating DPP4 (r = 0.55, p < 0.001), AST (r = 0.22, p = 0.017), ALT (r = 0.22, p = 0.016) and GGT (r = 0.27, p = 0.004) levels and with the presence of NAFLD (r = 0.28, p = 0.001), MS (r = 0.20, p = 0.019) and T2DM (r = 0.28, p = 0.001) (Table 4). This evidence concerns the gene DPP4 and type 2 diabetes mellitus.