The Inter-relationship between Sarcopenia and Osteoporosis : Molecular Mechanisms and Therapeutic Interventions.

Sarcopenia and osteoporosis are prevalent age-related musculoskeletal disorders that frequently coexist and interact, giving rise to the clinical entity known as osteosarcopenia. Although traditionally considered distinct entities, growing evidence indicates that muscle and bone are functionally integrated through biomechanical and biochemical crosstalk. Sarcopenia is characterized by progressive loss of skeletal muscle mass, strength, and function, whereas osteoporosis is defined by reduced bone mineral density (BMD) and microarchitectural deterioration, resulting in increased fracture risk. Both conditions share common risk factors, including aging, chronic inflammation, hormonal changes, physical inactivity, and nutritional deficiencies. Emerging evidence highlights the important role of muscle-derived myokines, bone-derived osteokines, and adipokines in mediating inter-organ communication within the musculoskeletal unit. This narrative review synthesizes current evidence supporting osteosarcopenia as an integrated musculoskeletal syndrome, with a particular focus on biomechanical loading, biochemical crosstalk, and inflammatory signaling. In addition, we discuss diagnostic challenges and therapeutic strategies, emphasizing integrated assessment and management approaches that target skeletal fragility, muscle dysfunction, and musculoskeletal interfaces to reduce frailty, falls, and fractures in aging populations.