Airflow limitation predicts muscle wasting in COPD patients

Severe airflow limitation tends to contribute to future muscle wasting in patients with chronic obstructive pulmonary disease (COPD) and ever-smokers at risk of COPD, reports a recent study.

“Airflow limitation with a peak expiratory flow (PEF) slightly below 90 percent of the predicted value may require intervention to prevent future muscle loss,” the authors said.

A total of 114 participants were included in this longitudinal observational study. Over a median follow-up period of 5 years, their body mass index remained stable, but their weight and muscle cross-sectional area (CSA) decreased over time, while their subcutaneous fat thickness increased.

Notably, reduced forced expiratory volume in 1 second and PEF at baseline were significantly associated with future decline in muscle CSA.

In this study, the authors used chest computed tomography (CT) images to assess airway and emphysematous lesions as the square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm and the percentage of low attenuation volume.

Muscle mass was measured using CSAs of the pectoralis and erector spinae muscles. On the other hand, fat mass was estimated using the subcutaneous fat thickness at the level of the eighth rib measured via chest CT images. Finally, the authors carried out statistical analyses using linear mixed-effects models.

“Weight and muscle loss are predictors of poor outcomes in chronic obstructive pulmonary disease,” the authors said. “However, to our knowledge, no study has investigated the predictors of longitudinal weight loss or its composition from functional and morphological perspectives.”