The effects of pulmonary rehabilitation on endothelial function and arterial stiffness in patients with chronic obstructive pulmonary disease

Objectives Cardiovascular disease is a major cause of mortality in chronic obstructive pulmonary disease (COPD) and endothelial dysfunction may enhance the mortality risk. Exercise training has shown to be beneficial for improvement of endothelial function in patients with cardiovascular disease, but this remains unclear in COPD. Thus, this study aimed to assess the effect of exercise-based pulmonary rehabilitation (PR) on endothelium function, arterial stiffness and plasma nitrite levels in patients with COPD. Methods Patients with COPD engaged a 48-session PR program. Reactive hyperaemia index (RHI), augmentation index (AIx), and heart rate (HR) assed by peripheral arterial tonometry (PAT), plasma nitrite levels, systemic blood pressure, functional capacity (six-minute walk test) and the BODE index were assessed at baseline and after 24 and 48 sessions of PR. Plasma nitrite levels were also assessed before and after the first session of PR. Results Twenty-one subjects were included and completed 24 PR sessions, and 16 subjects completed 48 sessions. It was observed that a poorer AIx adjusted for HR in frequent COPD exacerbators (4.67 +/- 16.5 vs. 20.9 +/- 12.9; p = .02). PR improved functional capacity (380 +/- 107 m vs. 442 +/- 115 m; p < .001) and the BODE index (6 [2.8] vs. 4 [3]; p = .001), but did not change HR, systemic arterial pressure, RHI, AIx, and plasma nitrite levels during the follow-up. Plasma nitrite levels reduced after the first session of PR (0.074 [0.079] mu M vs. 0.061 [0.04] mu M; p = .027). The acute change in plasma nitrite levels correlated with RHI in patients with preserved endothelial function (r = 0.71; p = .01). Conclusions Although exercise-based PR improved functional capacity and the BODE index, it did not change endothelial function and arterial stiffness in patients with COPD.