Sarcopenia and Muscle Aging: Updated Insights into Molecular Mechanisms and Translational Therapeutics.

Sarcopenia is a progressive, age-related condition characterized by the loss of skeletal muscle mass, strength, and function, which increases the risk of falls, frailty, and loss of independence. Despite growing recognition and its incorporation into geriatric assessments, there is still no approved pharmacological treatment. This review provides an updated overview of sarcopenia, encompassing diagnostic criteria, biological mechanisms, and emerging therapeutic strategies. Key molecular features include mitochondrial dysfunction, nicotinamide adenine dinucleotide (NAD⁺) decline, fiber-type alterations, and dysregulation of myokines. Recent singlecell and multi-omics studies have revealed the heterogeneity of muscle tissue and distinct cell-type-specific aging patterns. Therapeutic efforts are evolving beyond lifestyle interventions toward targeted approaches, including myostatin inhibitors, NAD⁺ boosters, senolytics, and microbiome modulators. However, clinical translation remains constrained by heterogeneity in trial design and the absence of standardized outcome measures. Future sarcopenia care will likely involve precision medicine guided by biomarkers and supported by digital monitoring tools. Progressing from molecular discovery to clinical application will be essential for preserving muscle health and function in aging populations.