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] µM vs. 0.061 [0.04] µM; 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.

The minimal important difference for Glittre-ADL test in patients with chronic obstructive pulmonary disease.

OBJECTIVE: To determine Glittre-ADL test minimal important difference in patients with chronic obstructive pulmonary disease. METHODS: This is quasi-experimental study. Sixty patients with moderate to very severe chronic obstructive pulmonary disease (age 64.1, SD=9.09 years; forced expiratory volume in the first second 37.9, SD=13.0% predicted participated in a pulmonary rehabilitation program based on physical training, conducted over 24 sessions supervised, three times a week, including aerobic training in treadmill and resistance training for upper limbs and lower limbs. The main outcomes were the Glittre-ADL test and six-minute walk test, before and after 24 sessions of pulmonary rehabilitation. The minimal important difference was established using the distribution and anchor-based methods. RESULTS: Patients improved their functional capacity after the pulmonary rehabilitation. The effect sizes of Glittre-ADL test and six-minute walk test improvement were similar (0.45 vs 0.44, respectively). The established minimal important differences ranged from -0.38 to -1.05. The reduction of 0.38min (23s) corresponded to a sensitivity of 64% and a specificity of 69% with an area under the curve of 0.66 (95%CI 0.51-0.81; p=0.04). Subjects who achieved the minimal important difference of -0.38min for the Glittre-ADL test had a superior improvement of approximately 42m in the six-minute walk test when compared to patients who did not. CONCLUSIONS: The present findings suggest -0.38min as the minimal important difference in the time spent in the Glittre-ADL test after 24 sessions of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease. TRIAL REGISTRATION: NCT03251781 (https://clinicaltrials.gov/ct2/show/NCT03251781).