ADRB2 and sarcopenia: We examined whether the individual polymorphism in the Methylenetetrahydrofolate reductase [MTHFR 1.p36.2 A > C (rs1801131)], Alpha-actinin-3 [ACTN3 11.q13.2 C > T (rs1815739)], Nuclear respiratory factor 2 [NRF2 15q21.2 C > A (rs12594956)], Vitamin D receptor [VDR FokI 12q13.1 T > C (rs2228570)], Adrenoceptor beta 2 [ADRB2 5q32 G > A (rs1042713)], C-X3-C motif chemokine receptor 1 [CX3CR1 3.p22 C > T (rs3732379)], and Neuronal PAS domain-containing protein 4 [NPAS4 11q13.2 A > G (rs7947391)] genes are associated with sarcopenia in older adults.