Investigating sarcopenia and mucus plugging by chest computed tomography in patients with severe chronic obstructive pulmonary disease

Abstract To determine the relationship between mucus plugging and CT-derived parameters of sarcopenia in routine chest CT-scans. Patients with advanced Chronic Obstructive Lung Disease (COPD GOLD 3 or 4) were investigated. Mucus plug score (MPS) and cross-sectional muscle area (CSA) of pectoralis and erector spinae muscle of each patient was assessed by two radiologists. Statistics included non-parametric group comparison, multivariate analysis, and inter- and intrarater agreement. Median age of 123 patients (47 female) was 66 years. In 63 patients (15 females) no mucus plugging was found. 31 patients (15 females) had 1–2 mucus plugs and 29 patients (17 females) had a mucus plug of ≥ 3. PMCSA and ESMCSA were not independently associated with MPS; however, the association between PMCSA and MPS was modified by body weight, with a significant negative correlation between body weight and PMCSA in patients with higher MPS (≥ 3). Inter- and intrarater agreement was very good (ICC 0.899 or higher). Imaging based evaluation of MPS and CSA is reliable on routine chest CT-scans. Patients with more advanced COPD exhibited a higher MPS and larger PMCSA relative to body weight, possibly due to the greater muscular effort required for breathing.