A limitation of this study is the cross-sectional design which does not allow to establish a causal nexus between increased plasma DPP4 activity/concentration and NAFLD; longitudinal studies are warranted in order to test the role of DPP4 as a marker of NAFLD development and progression in individuals at high risk, as those with T2DM and metabolic disease. This evidence concerns the gene DPP4 and metabolic disease.