1. Introduction
muscle mass, sarcopenia, Sarcopenia
SARCOPENIA, SYNDROME, SARCOPENIA
Sarcopenia is a geriatric syndrome characterized by decreased physical performance, muscle mass, and strength. Since the intake of 5-aminolevulinic acid (ALA) with iron can increase muscle mass and mitochondria in mice and elevate physical exercise performance in humans, the beneficial effects of ALA in patients with sarcopenia are expected, but this remains unexplored in the literature. This study aimed to assess the efficacy and dose dependency of ALA combined with iron in sarcopenia by measuring skeletal muscle mass index (SMI). Subjects with sarcopenia were enrolled and randomized into the ALA and sodium ferrous citrate (SFC) intake groups (ALA50/SFC29, ALA100/SFC29, ALA150/SFC29, ALA 100/SFC57, and ALA0/SFC29 placebo) and ingested the assigned study food for 12 weeks. The primary endpoint, the change in SMI from baseline to week 12, did not differ significantly between the groups. Hand grip significantly increased or tended to increase from baseline after 12 weeks with all doses of ALA or SFC compared with the placebo group. No consistent changes were observed in the other endpoints, including calf circumference, physical function, or quality of life (QOL). Although this study suggests safe administration and the possibility of ALA improving hand grip strength in patients with sarcopenia, further investigation is required.Sarcopenia is a geriatric syndrome characterized by decreased physical performance and a decline in overall muscle mass and strength, mainly due to aging; Rosenberg first proposed it in 1989 [To prevent sarcopenia, appropriate nutrient intake, especially protein consumption (1.0 g per kg ideal body weight per day or more), is considered necessary [A natural amino acid synthesized in animals and plants, 5-aminolevulinic acid (ALA), is a porphyrin precursor. Porphyrins are synthesized by linking eight ALA molecules. Porphyrins, which bind to iron ions, are known as heme. Heme acts as a cofactor for many proteins, such as hemoglobin and cytochrome, and plays essential roles in energy metabolism in the mitochondria. It was reported that the intake of ALA with iron increased mouse muscle mass and mitochondria and elevated physical exercise performance in humans [