Sarcopenia is an age-related condition of slow, progressive loss of muscle mass and strength, which contributes to frailty, increased risk of hospitalisation and mortality, and increased health care costs. The incidence of sarcopenia is predicted to increase to >200 million affected older adults worldwide over the next 40 years, highlighting the urgency for understanding biological mechanisms and developing effective interventions. An understanding of the mechanisms underlying sarcopenia remains incomplete. Iron in the muscle is important for various metabolic functions including oxygen supply and electron transfer during energy production, yet these same chemical properties of iron may be deleterious to the muscle when either in excess or when biochemically unshackled (e.g., in ferroptosis), it can promote oxidative stress and induce inflammation. This review outlines the mechanisms leading to iron overload in muscle with aging and evaluates the evidence for the iron overload hypothesis of sarcopenia. Based on current evidence, studies are needed to: 1) determine the mechanisms leading to iron overload in skeletal muscle during aging; and 2) investigate whether skeletal muscles are functionally deficient in iron during aging leading to impairments in oxidative metabolism.

中文翻译：

---

骨骼肌铁稳态的年龄相关变化

肌肉减少症是一种与年龄相关的疾病，会导致肌肉质量和力量缓慢、进行性丧失，导致身体虚弱、住院和死亡风险增加，并增加医疗保健费用。预计未来 40 年全世界肌肉减少症的发病率将增加到超过 2 亿受影响的老年人，这突出了了解生物学机制和开发有效干预措施的紧迫性。对肌肉减少症潜在机制的理解仍然不完整。肌肉中的铁对于各种代谢功能很重要，包括能量产生过程中的供氧和电子转移，但铁的这些相同化学性质可能在过量或生化释放时（例如铁死亡）对肌肉有害，它可以促进氧化应激并诱发炎症。这篇综述概述了随着衰老导致肌肉铁超载的机制，并评估了肌肉减少症铁超载假说的证据。根据目前的证据，需要进行研究以：1) 确定在衰老过程中导致骨骼肌铁过载的机制；2) 研究骨骼肌在衰老过程中是否功能性缺铁导致氧化代谢受损。