INS and sarcopenia: Current studies on the pathogenesis of sarcopenia mainly include the imbalance of skeletal muscle protein synthesis and decomposition, inflammatory factors and insulin resistance, oxidative stress and mitochondrial dysfunction, the imbalance of dynamic regulation of cytokines, changes in hormone levels, motor neuron degeneration, genes and genetics, etc., and these factors interact with each other, resulting in varying degrees of muscle mass and/or muscle strength decline.