Resting energy expenditure and associated factors are similar in patients with chronic obstructive pulmonary disease and interstitial lung disease

Abstract

Background

Few studies have measured the resting energy expenditure (REE) in patients with interstitial lung disease (ILD). Whether REE characteristics in patients with chronic obstructive pulmonary disease (COPD) and ILD are similar remains unknown. We aimed to investigate whether REE and its associated factors were similar in patients with COPD and ILD.

Methods

This study included 223 patients (COPD, 102; ILD, 121) who were admitted to our hospital with a diagnosis of COPD or ILD and for whom indirect calorimetry was performed. The measured REE (mREE) was calculated using Weir's formula after indirect calorimetry. Patients with COPD and ILD were classified into two groups by propensity score matching. Multiple regression analysis was used to compare REE between the two groups and examine REE and its associated factors in each group.

Results

Body composition and other characteristics differed significantly between the two groups before propensity score matching. Forty-seven patients each were classified into the COPD and ILD groups after propensity score matching. Body mass index was 21.3 ± 3.8 kg/m² and 21.2 ± 3.2 kg/m² in the COPD and ILD groups, respectively (p = 0.877). The mREE was 1308 ± 204 kcal and 1329 ± 245 kcal in the COPD and ILD groups (p = 0.661). Multiple regression analysis showed that REE was associated with age and FFM in the COPD group and with FFM in the ILD group.

Conclusions

FFM plays an important role in determining REE in both diseases, suggesting that REE in patients with COPD and ILD are similar.