PPARGC1A and obesity due to melanocortin 4 receptor deficiency: The IPA results revealed 10 common candidate genes (CFB, CXCL2, HSD11B1, IGF1, IL6, NTN1, PCSK1, PPARGC1A, SOD2, and TF) that were inhibited in osteoporosis, sarcopenia, and diabetes but activated in obesity for all participants in the control group (Figure 4).