Abstract
COPD is a complex disease with pulmonary and extrapulmonary manifestations intensively studied due to the numerous pathologic processes involved. Its prevalence is increasing, representing the fourth leading cause of mortality worldwide. Sarcopenia can occur in COPD patients with common risk factors. Sarcopenia is characterized by a decrease in muscle mass and function with consequences on muscle performance. Muscle changes can be measured by different methods: MRI, DXA, BIA, CT or biopsy. The prevalence of sarcopenia has been studied in numerous studies with varying results. This review identifies the main risk factors that contribute to the variable outcomes with a focus on the characteristics of the studied population, the criteria for defining sarcopenia and the methods used to measure muscle mass, strength and physical performance.