LEP and obesity due to melanocortin 4 receptor deficiency: It has been suggested that a vicious circle of maintaining a high volume of adipose tissue and skeletal muscle inflammation, triggers the development and acceleration of sarcopenic-obesity with a complex interplay between a number of mechanisms that are beyond the scope of this review (i.e. adipocyte-like phenotype of muscle progenitor cells, insulin resistance, impaired neuromodulation of contraction, leptin resistance, impaired endocrine function, reduced release of adiponectin, increased glycation products and oxidative stress etc.)(23, 63, 66).