NOS3 and sarcopenia: Other SNPs associating with sarcopenia include, fat mass and obesity associated gene (FTO) rs9939609 from fat, sex hormone Estrogen receptor 1 gene (ESR1) rs4870044, nitric oxide synthase 3 gene (NOS3) rs1799983 in the vascular endothelium, and Thyrotropin-releasing hormone receptor (TRHR) rs783255 [36].