Assessment of muscle dysfunction in COPD patients: A case-control study

Introduction: peripheral muscle dysfunction satellite of chronic obstructive pulmonary disease (COPD) has emerged in recent years as a major factor which limits patients' ability to exercise.
Methods: This study is a case-control investigation of the associations between COPD and muscle dysfunction. Cases and control subjects were recruited to evaluate their body composition using bioelectrical impedance (BIA). Quadriceps strength and endurance tests were performed. Dyspnoea was estimated by the mMRC scale.
The patients were redirected from the department of pulmonary diseases of Batna, Algeria.
The healthy subjects were volunteers without any lung, heart or systemic diseases or handicap in physical effort.
Results: 175 patients with stable COPD (9 female and 166 male) aged between 40–86 years, mean FEV1 52 ± 21% and 175 age-and-sex-matched healthy subjects (FEV1: 91± 9%) were included in this study. The cigarette consumption was 35 (20) pack/years in COPD patients vs 15 (15) pack/years in healthy subjects. The classification of airflow limitation showed that 19.43% of patients were classified GOLD I, 30.29% (GOLD II), 33.71% (GOLD III), and 16.57% (GOLD IV). 22. 85% of COPD patients were classified in (category A) ,17.14% (category B) ,16.57% (category C) and 43.42% (category D). fat-free mass index (FFMI) was 19.3 (1.6) kg/m2 in COPD patients vs 18 (4.7) kg/m2 in controls.
Quadriceps strength was 109.27 (42.8) Nm in COPD patients vs 141.6 (15) Nm in healthy subjects. The quadriceps endurance was 3.75 (1.14) min in patients vs 16.6 (15) min in controls.
Conclusion: This study supports the idea that skeletal muscle mass, quadriceps strength and endurance, were adversely affected in patients with COPD.