GPT and obesity due to melanocortin 4 receptor deficiency: In males, after adjustment for age, diabetes duration, current smoking, FPG, HbA1c, anti-diabetic therapy, and family history of diseases, including diabetes, hypertension, obesity, and hyperlipidemia, the associations of BMI with hypertension were significantly mediated by ALT, AST, GGT and AST/ALT (Fig. 2).