GPT and obesity due to melanocortin 4 receptor deficiency: Among the participants stratified into three groups of grade I, grade II, and grade III obesity, as well as among the participants stratified into male and female groups, univariate correlation analysis identified a negative association (P < 0.01) for age, positive associations (P < 0.01) for BMI, muscle mass, alanine aminotransferase, and creatinine.