Skeletal muscle dysfunction and sarcopenia in bronchiectasis: clinical and biological mechanisms

Bronchiectasis is a chronic respiratory disease characterized by irreversible bronchial dilation, persistent infection, and ongoing airway inflammation. Beyond pulmonary damage, it is increasingly recognized as a systemic condition with important extrapulmonary manifestations. Among these, skeletal muscle dysfunction and sarcopenia are clinically significant, contributing to exercise intolerance, reduced physical activity, impaired quality of life, and poorer outcomes. The mechanisms underlying muscle impairment are multifactorial, involving chronic systemic inflammation, physical inactivity and deconditioning, altered protein metabolism, hypoxemia, oxidative stress, nutritional abnormalities, aging, and comorbidities. Sarcopenia – defined as the loss of muscle mass and function – is particularly relevant in older individuals and patients with advanced disease. This review summarizes current clinical evidence on skeletal muscle dysfunction and sarcopenia in bronchiectasis, outlines the key biological mechanisms involved, and discusses their clinical implications and potential therapeutic strategies. Early recognition and comprehensive, multidisciplinary interventions targeting both pulmonary and systemic factors are essential to improve functional status and prognosis.