Medical Director Responsibilities for Outpatient Pulmonary Rehabilitation Programs in the United States: 2019: A STATEMENT FOR HEALTH CARE PROFESSIONALS FROM THE AMERICAN ASSOCIATION OF CARDIOVASCULAR AND PULMONARY REHABILITATION (AACVPR)

Pulmonary rehabilitation restores limb muscle mitochondria and improves the intramuscular metabolic profile

BACKGROUND

Exercise, as the cornerstone of pulmonary rehabilitation, is recommended to chronic obstructive pulmonary disease (COPD) patients. The underlying molecular basis and metabolic process were not fully elucidated.

METHODS

Sprague-Dawley rats were classified into five groups: non-COPD/rest ( n  = 8), non-COPD/exercise ( n  = 7), COPD/rest ( n  = 7), COPD/medium exercise ( n  = 10), and COPD/intensive exercise ( n  = 10). COPD animals were exposed to cigarette smoke and lipopolysaccharide instillation for 90 days, while the non-COPD control animals were exposed to room air. Non-COPD/exercise and COPD/medium exercise animals were trained on a treadmill at a decline of 5° and a speed of 15 m/min while animals in the COPD/intensive exercise group were trained at a decline of 5° and a speed of 18 m/min. After eight weeks of exercise/rest, we used ultrasonography, immunohistochemistry, transmission electron microscopy, oxidative capacity of mitochondria, airflow-assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI), and transcriptomics analyses to assess rectal femoris (RF).

RESULTS

At the end of 90 days, COPD rats' weight gain was smaller than control by 59.48 ± 15.33 g ( P  = 0.0005). The oxidative muscle fibers proportion was lower ( P  < 0.0001). At the end of additional eight weeks of exercise/rest, compared to COPD/rest, COPD/medium exercise group showed advantages in weight gain, femoral artery peak flow velocity (Δ58.22 mm/s, 95% CI: 13.85-102.60 mm/s, P  = 0.0104), RF diameters (Δ0.16 mm, 95% CI: 0.04-0.28 mm, P  = 0.0093), myofibrils diameter (Δ0.06 μm, 95% CI: 0.02-0.10 μm, P  = 0.006), oxidative muscle fiber percentage (Δ4.84%, 95% CI: 0.15-9.53%, P  = 0.0434), mitochondria oxidative phosphorylate capacity ( P  < 0.0001). Biomolecules spatial distribution in situ and bioinformatic analyses of transcriptomics suggested COPD-related alteration in metabolites and gene expression, which can be impacted by exercise.

CONCLUSION

COPD rat model had multi-level structure and function impairment, which can be mitigated by exercise.

Exercise and Quality-of-Life Outcomes of Two Versus Three Weekly Sessions of Pulmonary Rehabilitation

PURPOSE

This study aimed to assess whether there are differences in exercise or health-related quality-of-life (HRQoL) outcomes following twice-weekly supervised sessions of pulmonary rehabilitation (PR) compared with three times weekly over an 8-wk program in patients with chronic obstructive pulmonary disease (COPD).

METHODS

We conducted a quasi-experimental, single-center observational study using 198 subjects who completed two supervised PR sessions (intervention group) compared with 208 historical controls who completed three weekly sessions. We assessed between-group differences in outcomes after balancing groups using inverse probability of treatment weighting (IPTW) of propensity scores, followed by regression adjustment.

RESULTS

Both groups achieved clinically and statistically significant improvements in exercise and HRQoL following the PR program. After IPTW and regression adjustment, the intervention group had a lower post-PR 6-min walk time by 1.2: 95% CI, -12.9 to 10.5 m (P = .84), compared with the control group. Although post-PR COPD Assessment Test (CAT) scores decreased in both groups, the intervention group had a higher post-PR CAT score by 1.5: 95% CI, 0.37 to 2.66 a.u. (P = .01), compared with the control group. All other HRQoL measures failed to reach statistical significance. None of the between-group differences reached minimal clinically important differences for COPD.

CONCLUSIONS

Our findings support current international guidelines for twice-weekly supervised PR sessions combined with unsupervised home exercise sessions. We conclude there is no disadvantage in running a PR program for patients with COPD using twice-weekly supervised sessions compared with three times weekly supervised sessions.