High-protein diet during pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

Iintroduction: The prevalence of cachexia in patients with chronic obstructive pulmonary disease (COPD) is high and associated with reduced quality of life, increased mortality and morbidity. We aimed to test the effect of a high protein diet combined with exercise on fat-free mass (FFM), functional capacity, symptom burden and dyspnoea. 

Methods: Outpatients with COPD and severe or very severe (GOLD grade III-IV) disease and malnutrition commencing pulmonary rehabilitation were randomised to a high-protein diet or standard care. FFM was measured by bio-impedance analysis (BIA), mid-upper arm circumference (MUAC) and mid-thigh circumference (MTC), peripheral muscle function by six-minute walking distance (6MWD) and handgrip strength (HGS), symptoms by the COPD Assessment Trial (CAT) and dyspnoea by the Medical Research Council dyspnoea scale and Borg scores; all at baseline and after 12 weeks. 

Results: Ten out of 13 randomised patients completed the trial. The intervention group was superior to the control group with respect to 6MWD (97 ± 93 m, p = 0.04) at 12 weeks. No differences were observed between the groups in HGS, anthropometrics, symptom burden or dyspnoea. 

Conclusion: In patients with COPD attending rehabilitation, a high protein diet combined with physical exercise had a clinically relevant effect on walking distance.