PPARGC1A and type 2 diabetes mellitus: Many studies have revealed that genetic factors predispose an individual to NAFLD or type 2 diabetes and have led to the development of noninvasive biomarkers for early diagnosis of type 2 diabetes complicated with NAFLD, such as adiponectin, leptin, peroxisome proliferator-activated receptor alpha (PPAR-α), adiponutrin/patatin-like phospholipase domain-containing protein 3 (PNPLA3), peroxisome proliferator-activated receptor γ (PPAR-γ) and Peroxisome proliferator-activated receptor γ co-activator 1α (PPARGC1A) [12–19].