Longevity & AgingSkeletal Muscle Is a Hidden Endocrine Organ Driving Metabolic Health
Skeletal muscle is now understood as a major endocrine organ, not just a contractile tissue. It responds to hormones like GH, IGF-1, testosterone, insulin, and glucocorticoids, while simultaneously secreting bioactive proteins called myokines—including irisin, IL-6, IL-15, BDNF, myostatin, and FGF21—that regulate metabolism, inflammation, and organ crosstalk. This 2025 narrative review synthesizes evidence showing that muscle endocrine dysfunction from inactivity, hormonal resistance, or chronic inflammation drives obesity, type 2 diabetes, insulin resistance, and sarcopenia. The review also highlights therapeutic opportunities: structured exercise, hormone replacement therapy, and anabolic agents can preserve muscle function and myokine signaling, with myokines emerging as promising biomarkers and drug targets in endocrine-metabolic disease management.
