In a longitudinal study conducted by Galderisi A., the effect of incretins on cell function was studied in a group of adolescents with obesity and prediabetes, demonstrating that the significantly increased incretin effect serves as a protective factor for beta-cell function over time, compared to young individuals who exhibit a low incretin effect characterized by a low-insulin-sensitivity phenotype [76]. Here, GCG is linked to obesity due to melanocortin 4 receptor deficiency.