IL6 and obesity due to melanocortin 4 receptor deficiency: Previous studies have demonstrated that obesity causes a persistent low-grade inflammation in the body and the production of pro-inflammatory factors, such as TNF-α, IL-1β, IL-6, etc., which inhibit skeletal muscle cell proliferation and differentiation, promote skeletal muscle protein degradation, and induce apoptosis, reducing skeletal muscle mass through various signaling pathways (38, 39).