IGF1 and sarcopenia: A reduction in circulating IGF‐1 in adulthood is a major risk factor for the development of a number of age‐associated pathologies and diseases, including diabetes, osteoporosis, sarcopenia, cardiovascular disease, dementia, and Alzheimer's disease (Bartke et al., 2016; Barzilai et al., 2012; Laughlin, Barrett‐Connor, Criqui, & Kritz‐Silverstein, 2004; Lombardi et al., 2005; Toth et al., 2015; Westwood et al., 2014).