Quantitative Computed Tomography Assessment of Pectoralis and Erector Spinae Muscle Area and Disease Severity in Chronic Obstructive Pulmonary Disease Referred for Lung Volume Reduction

Abstract

Patients with advanced chronic obstructive pulmonary disease (COPD) develop skeletal muscle loss (sarcopenia) that is associated with adverse clinical outcomes including mortality. We evaluated if thoracic muscle area is associated with clinical outcomes in patients with severe COPD. We analyzed consecutive patients with severe COPD undergoing evaluation for lung volume reduction from 2015 to 2019 (n = 117) compared to current and former smoking controls undergoing lung cancer screening with normal lung function (n = 41). Quantitative assessments of pectoralis muscle (PM) and erector spinae muscle (ESM) cross sectional area (CSA) were related to clinical outcomes including composite endpoints. Our results showed a reduction in PM CSA but not ESM CSA was associated with the severity of GOLD stage of COPD. Current smokers demonstrated reduced PM CSA which was similar to that in COPD patients who were GOLD stages 3 and 4. PM CSA was associated positively with FEV1, FEV₁% predicted, FVC, DLCO, and FEV₁/FVC ratio, and was associated negatively with the degree of radiologic emphysema. ESM correlated positively with DLCO, RV/TLC (a marker of hyperinflation), and correlated negatively with radiologic severity of emphysema. Kaplan-Meier analysis showed that reductions in PM but not ESM CSA was associated with the composite end point of mortality, need for lung volume reduction, or lung transplant. In conclusion, in well-characterized patients with severe COPD referred for lung volume reduction, PM CSA correlated with severity of lung disease, mortality, and need for advanced therapies. In addition to predicting clinical outcomes, targeting sarcopenia is a potential therapeutic approach in patients with severe COPD.

Keywords:

• COPD
• sarcopenia
• cachexia
• skeletal muscle
• emphysema
• lung volume reduction

Amy Attaway and Srinivasan Dasarathy contributed to conceptualization, design, data acquisition, analysis, interpretation, writing the manuscript, and obtaining funding. Nicole Welch contributed to interpretation of data, manuscript writing and editing, and preparing figures. Ruchi Yadav, Joe Zein, Marielle Engelen, Yvonne Meli, Umur Hatipoglu, and Annette Bellar contributed to analysis and interpretation of data, reviewing and editing manuscript.

Data availability statement

A data availability statement provided by the authors is available upon request.

Disclosure statement

The authors report no other conflicts of interest. The funders had no role in the design, analysis or interpretation of the data.

Additional information

Funding

R21 AR 071046; RO1 GM119174; RO1 DK113196; P50 AA024333; RO1 AA021890; 3U01AA026976 – 03S1; UO1 AA 026976; R56HL141744; UO1 DK061732 to SD. N.W. partially supported by the American College of Gastroenterology Clinical Research Award K12 5K12HL141952. A.A. and K12 5K12HL141952 and internal funding through the Research Program Committee (RPC) at Cleveland Clinic.