As observed for circulating DPP4 activity, plasma DPP4 concentration associated with the presence of NAFLD (r = 0.24, p = 0.03), MS (r = 0.27, p = 0.015) and with T2DM diagnosis (r = 0.41, p ≤ 0.001) (Table 4). Here, DPP4 is linked to type 2 diabetes mellitus.