NPAS4 and sarcopenia: Although no significant differences in sarcopenia risk were observed in ADRB2, and NPAS4 genotypes, evidence points to the importance of these genes in muscle strength (Ahmetov and Fedotovskaya, 2015; Rankinen et al., 2016) and quality (Kharraz et al., 2013; Arnold et al., 2015; Chazaud, 2016).