Preliminary study: comparative effects of lung volume therapy between slow and fast deep-breathing techniques on pulmonary function, respiratory muscle strength, oxidative stress, cytokines, 6-minute walking distance, and quality of life in persons with COPD

Abstract

Background: Lung volume therapy with the Voldyne^® device can improve lung volume and has a nonsignificant benefit on respiratory muscle strength via the slow deep-breathing technique (SDBT); whereas respiratory muscle training with a respiratory muscle trainer via the fast deep-breathing technique (FDBT) has produced a significant improvement in people with COPD. Thus, the aim of this study was to compare the efficiency of lung volume therapy with the Voldyne^® device with the SDBT and FDBT on pulmonary function, respiratory muscle strength, oxidative stress, cytokines, walking capacity, and quality of life (QoL) in people with COPD.

Methods: A total of 30 COPD patient volunteers with mild (stage I) to moderate (stage II) severity were randomized into two groups: SDBT (n=15) and FDBT (n=15). Pulmonary function (FVC, FEV₁, and FEV₁/FVC), maximal inspiratory mouth pressure (PI_max), oxidative stress status (total antioxidant capacity [TAC], glutathione [GSH], malondialdehyde [MDA], and nitric oxide [NO]), inflammatory cytokines (tumor necrosis factor-alpha [TNF-α] and IL-6), 6-minute walking distance (6MWD), and total clinical COPD questionnaire (CCQ) score were evaluated before and after 4 weeks of training.

Results: All the parameters had no statistical difference between the groups before training. The PI_max, TAC, IL-6, total QoL score, and 6MWD changed significantly in the SDBT group after the 4-week experiment as compared to those in the pre-experimental period, whereas FVC, FEV₁, FEV₁%, FEV₁/FVC%, PI_max, TAC, MDA, NO, TNF-α, IL-6, 6MWD, and total CCQ score changed significantly in the FDBT group as compared to those in the pre-experimental period. The FEV₁%, PI_max, TNF-α, IL-6, and total CCQ score differed significantly in the FDBT group in the post-experimental period as compared to those in the SDBT group.

Conclusion: This preliminary study concluded that the application of incentive spirometry with the Voldyne^® device via fast deep breathing possibly improved respiratory muscle strength and QoL and reduced inflammatory cytokines, MDA, and NO better than that via slow deep breathing among people with COPD.

Keywords: 6-minute walking distance; COPD; cytokines; incentive spirometry; oxidative stress; quality of life.

Figure 1

Pulmonary function test: FVC (A), FEV₁ (B and C), FEV₁/FVC (D), and PI_max (E) between the SDBT (n=15) and FDBT (n=15) in the pre-experimental period (white bar) and post-experimental period (black bar). Notes: P-value was analyzed statistically using the post hoc Bonferroni test. Each bar represents the mean and SD. Abbreviations: PI_max, maximal inspiratory pressure; SDBT, slow deep-breathing technique; FDBT, fast deep-breathing technique.

Figure 2

Levels of TAC (A), MDA (B), NO (C), TNF-α (D), and IL-6 (E) for the SDBT (n=15) and FDBT (n=15) groups in the pre-experimental period (white bar) and post-experimental period (black bar). Notes: P-value was analyzed statistically using the post hoc Bonferroni test. Each bar represents the mean and SD. Abbreviations: TAC, total antioxidant capacity; MDA, malondialdehyde; NO, nitric oxide; TNF-α, tumor necrosis factor-alpha; SDBT, slow deep-breathing technique; FDBT, fast deep-breathing technique.

Figure 3

6MWD (A) and total QoL score (B) between the SDBT (n=15) and FDBT (n=15) groups in the pre-experimental period (white bar) and post-experimental period (black bar). Notes: P-value was analyzed statistically using the post hoc Bonferroni test. Each bar represents the mean and SD. Abbreviations: 6MWD, 6-minute walking distance; QoL, quality of life; SDBT, slow deep-breathing technique; FDBT, fast deep-breathing technique.