INS and sarcopenia: The pathophysiology of sarcopenia may be that 1) a decline in muscle fiber numbers with aging and an increase in fibrosis leads to muscle dysfunction; 2) the imbalance between muscle protein synthesis and regeneration leads to loss of skeletal muscle; 3) on the one hand, insulin resistance leads to the dysfunction of the use of glucose, on the other hand, it leads to muscle atrophy (4–6).