The impact of frailty syndrome on skeletal muscle histology: preventive effects of exercise

Frailty syndrome, a condition marked by increased vulnerability due to age-related physiological decline, exerts a profound impact on skeletal muscle structure and function. Despite its widespread prevalence, the underlying mechanisms contributing to frailty-associated muscle deterioration remain poorly elucidated. This study utilized histological and biochemical analyses in a murine model to investigate the effects of frailty syndrome on skeletal muscle. Mice were classified based on age and condition, including a subset subjected to an exercise intervention. Parameters evaluated included body weight, lean mass ratio, myofiber size and number, extracellular matrix (ECM) content, and myosin heavy chain isoform expression. Frailty syndrome led to increased body weight and ECM content, coupled with reductions in myofiber size and number, reflecting substantial structural and functional impairments in skeletal muscle. Exercise interventions effectively countered these deleterious changes, preserving myofiber morphology and reducing ECM expansion, thereby demonstrating the protective role of exercise in mitigating frailty-induced muscle deterioration. The study highlights the severe impact of frailty syndrome on skeletal muscle structure and integrity. Importantly, it underscores the potential of regular exercise as an effective therapeutic approach to prevent or reverse muscle deterioration associated with frailty, offering critical insights into managing age-related muscular degeneration.