IGF1 and sarcopenia: Sarcopenia is associated with not only numerous hormonal factors, including insulin-like growth factor-1 (IGF-1) [5], insulin [6], testosterone [7], and oxytocin [8] but also nutritional factors such as trace elements [9, 10], vitamin D, protein, leucine [11], polyunsaturated fatty acid (PUFA) [12], and body mass index (BMI) [13].