Effect of pulmonary rehabilitation on exhaled nitric oxide in patients with chronic obstructive pulmonary disease

Background - In patients with mild to moderate chronic obstructive pulmonar y disease (COPD) the exercise induced increase in exhaled nitric oxide (eNO ) parallels that observed in normal untrained subjects. There is no informa tion on the effects of the level of exercise tolerance on eNO in these pati ents. The aim of this study was to evaluate the effect of a pulmonary rehab ilitation programme including exercise training on eNO in patients with COP D. Methods - In 14 consecutive male patients with stable COPD of mean (SD) age 64 (9) years and forced expiratory volume in one second (FEV1) 55 (14)% pr edicted, fractional eNO concentration (Feno), peak work rate (Wpeak) and ox ygen uptake ( (V) over dot o(2)peak) were assessed at baseline (T-1), at th e end of a 1 month run in period (T0), and after an 8 week outpatient multi disciplinary pulmonary rehabilitation programme (T1) including cycloergomet er training. Results - Feno did not significantly differ at T-1 and T0 (mean (SE) 4.3 (0 .6) and 4.4 (0.6) ppb, respectively), whereas it rose significantly at T1 t o 6.4 (0.7) ppb (p <0.02). Compared with T0, both Wpeak and (V) over dot o( 2) were significantly (p <0.05) increased at T1 (mean (SE) Wpeak from 89 (5 .6) W to 109 (6.9) W); (V) over dot o(2)peak from 1.27 (0.1) 1/min to 1.48 (0.1) 1/min). A significant correlation was found between baseline FEV, and the change in Feno following the rehabilitation programme (r=-0.71; p <0.0 5) and between changes in Feno and Wpeak from T0 to T1 (r=0.60; p <0.05). Conclusions - Pulmonary rehabilitation in patients with mild to moderate CO PD is associated with an increase in exhaled nitric oxide.