ABSTRACT
PURPOSE: Purpose of this study was to analyze the impact of a pulmonary rehabilitation (PR) program on the measured inspiratory capacity (IC) in patients with chronic obstructive pulmonary disease (COPD) while performing a 6-min walk test (6MWT). METHODS: Before and after PR, IC was measured by spirometry both at the beginning and at the end of the 6MWT for 15 patients with COPD in the PR group (PRG) and compared with a similar calisthenics training group (CTG; n = 15). In addition, the COPD Assessment Test (CAT), St George's Respiratory Questionnaire (SGRQ), and other lung function tests were recorded and compared. RESULTS: Both groups were not significantly different at baseline. Compared with the CTG, the PRG achieved a significant increase in the delta of IC measured during the 6MWT (0.5 ± 0.2 L [PRG] vs -0.2 + 0.2 L [CTG], P = .001). Significant differences were found for the 6MWT walking distance (PRG: 99 ± 36 m vs CTG: 5 ± 25 m, P = .001). No significant increase in dyspnea while performing the 6MWT was found in either group. The differences in the CAT score and the SGRQ Global score were significant only for the PRG in intragroup comparisons, whereas the intergroup comparison showed no significant differences. Except for residual volume, no significant changes in all parameters of the static lung function tests were observed in either group. CONCLUSION: Participation in a PR may lead to a significant and clinically relevant increase in IC and the walking distance. Additional research is necessary to define the effects of this increase in IC on exercise capacity.
Subject(s)
Exercise Therapy/methods , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Disease, Chronic Obstructive/rehabilitation , Walking/physiology , Aged , Female , Humans , Inspiratory Capacity , Male , Middle Aged , Prospective Studies , Severity of Illness Index , Walk TestABSTRACT
BACKGROUND: Pulmonary rehabilitation (PR) improves oxidative capacity of peripheral muscles in patients with chronic obstructive pulmonary disease (COPD). The exercise-induced oxidative skeletal muscle adaptation in COPD patients with inherited alpha-1 antitrypsin deficiency (A1ATD) has not been studied. OBJECTIVES: To compare PR effects on skeletal muscle adaptation in COPD patients with and without A1ATD. METHODS: Nine COPD patients with A1ATD (genotype PiZZ, 6 receiving A1AT augmentation therapy), and 10 'usual' COPD patients (genotype PiMM) performed an incremental cycling test and underwent musculus vastus lateralis biopsies before and after a 3-week PR program including exercise training. RESULTS: PiZZ and PiMM patients improved peak work rate following PR (+9 ± 11 W, p < 0.05, and +18 ± 9 W, p < 0.001, between-group difference p < 0.05). PiMM patients increased fibre type I (+8.1%), reduced fibre type IIA (-2.1%) and hybrid fibre type IIA/IIX proportion (-3.9%). Following PR, PiMM patients also raised mitochondrial signalling proteins PGC-1α (4.5-fold), and TFAM (6.4-fold). PiZZ patients had no change in fibre type I but showed a shift of type IIA/IIX (-8.8%) towards fibre type IIA distribution (+8.9%). The capillary to fibre ratio increased by 28% (p < 0.05) in PiZZ, whereas no change was observed in PiMM patients. Linear regression analysis revealed that diffusion capacity and A1AT therapy are predictor variables for myofibre type I response to PR (r2 = 0.684, p < 0.01). CONCLUSIONS: Following a 3-week PR with comparable training modalities, PiMM but not PiZZ patients increased the oxidative myofibre type I proportion. This skeletal muscle adaptation pattern suggests better improvement of exercise capacity in PiMM than in PiZZ patients with COPD.
