The Clinical Respiratory Journal · Jan 5, 2017
Clinical importance of cross-sectional area of intercostal muscles in patients with chronic obstructive pulmonary disease
By Ju S, Lee SJ, Park MJ et al.
INTRODUCTION: Limb muscle wasting is one of main systemic manifestation of chronic obstructive pulmonary disease (COPD). However, the change of respiratory muscle is unclear. OBJECTIVES: This study assessed the cross-sectional area (CSA) of the intercostal muscles (ICMs) in patients with COPD, using chest computed tomography (CT) and determined its association with the clinical characteristics of COPD. METHODS: They retrospectively reviewed 60 patients with stable COPD and compared them with 30 controls. CSA (mm² ) of the ICM on chest CT was measured at the midline level of the lateral arch of the bilateral first rib with a 3-mm slice thickness by using CT histogram software. The association with the clinical characteristics of COPD and with the control groups was assessed. RESULTS: CSA of the ICM and the CSA/body mass index (BMI) were lower in the COPD group than in the control group. Patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 4 had a significantly lower CSA of the ICM than patients with stage 1, 2, and 3. CSA of the ICM was positively associated with FEV₁ , %FEV₁ predicted, FEV₁ /FVC ratio, and BMI and negatively associated with age. However, there were no associations with PaO₂ , PaCO₂ , smoking status, 6-minute walk test, frequency of acute exacerbation of COPD, and serum C-reactive protein level. CONCLUSION: Intercostal muscle atrophy occurs in COPD patients and is associated with severity of airway obstruction, BMI, and increasing age.