B. Sample size. Considering a mean PAL value of 1.55 ± 0.265 in patients with moderate-severe COPD and an increase of 0.14 units as clinically relevant, since it is associated with a mortality reduction [Chest 2011;140:331-42], to detect a difference ≥0.14 units, by contrast bilateral hypothesis (with alpha risk=0.05, beta risk=0.20 and drop-out rate=10%), it is estimated to will be necessary to randomize 64 patients to each treatment arm.