INS and obesity due to melanocortin 4 receptor deficiency: In addition, in the study group, the highest AUCROC values in identifying the risk of obesity were found for leptin (AUCROC = 82.79%; cut-off = 17.7 ng/mL; p = 0.00004), insulin (AUCROC = 81.51%; cut-off = 9.5 μIU/mL; p = 0.00009) and C-peptide (AUCROC = 80.68%; cut-off = 2.3 ng/mL; p = 0.0001) concentrations as well as for HOMA-IR values (AUCROC = 79.97%; cut-off = 1.8; p = 0.0002).