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Chien M-Y1,2, Lee P3,4, Lin M-T4, Hsu N-C5
1National Taiwan University, School and Graduate Institute of Physical Therapy, Taipei, Taiwan, 2National Taiwan University Hospital, Center for Obesity, Lifestyle and Metabolic Surgery, Taipei, Taiwan, 3National Taiwan University Hospital, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Taipei, Taiwan, 4National Taiwan University Hospital, Center of Sleep Disorder, Taipei, Taiwan, 5National Taiwan University Hospital, Department of Hospital Medicine, Taipei, Taiwan
Background: Previous studies have reported significantly lower cardiopulmonary capacity and functional performance of both inspiratory muscles and knee extensors in patients with severe obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) is generally recommended as the first-line treatment for severe OSA patients. However, it is unknown whether exercise training or inspiratory muscle training (IMT) is effective for the patients with OSA.
Purpose: This study aimed to evaluate the effects of exercise training and IMT on apnea-hypopnea index (AHI) and cardiopulmonary capacity in patients with severe OSA.
Methods: This is a randomized controlled study with 52 patients diagnosed with severe OSA by polysomnography (PSG) divided into four groups: exercise training (Ex: n =15), IMT (IMT: n =13), CPAP (CPAP, n=13), and control group (CN, n=11). Each exercise training program consisted of 50 minutes of aerobic exercise training at moderate intensity (60%-80% peak oxygen uptake, VO2peak), three times a week for 12 weeks. The intensity of IMT started at 30% maximal inspiratory pressure for 12 weeks. The frequency for IMT is 15 min/ sessions, 2 sessions/day, 7 days per week. OSA severity was measured with one-night laboratory PSG before and following the 12-week intervention. All patients also received cardiopulmonary exercise test before and after intervention.
Results: Forty-one patients (78.8%) completed the intervention, and intention-to treat was used for data analysis. The results revealed a significant decrease of AHI (52.0±16.3 /h to 39.7±26.6 /h) in the exercise group compared to the IMT group (52.7±14.0 /h to 57.3±15.9 /h) after training (p 0.05). CPAP group and control group did not show significant changes of AHI after 12-week intervention (p>0.05). In addition, exercise group showed a significant improvement of VO2peak (mean difference of 1.99 mi/kg/min)compared to the other three groups (p 0.05).
Conclusion(s): Our results indicated that exercise training gained a significant improvement of AHI and cardiopulmonary capacity compared to the other treatments. However, 12 weeks of IMT could not improve AHI, and possibly aggravated the severity of OSA.
Implications: A significantly lower functional performance of inspiratory muscles of patients with OSA was shown because of repetitive inspiratory effort against an obstructed airway and intermittent hypoxia. IMT, which was meant to increase the strength of inspiratory muscles was shown to have adverse effects on the severity of OSA in this study. General aerobic exercise could be an alternative or complementary approach to existing therapies for OSA.
Keywords: Obstructive sleep apnea, inspiratory muscle training, apnea-hypopnea index
Funding acknowledgements: The authors thank the National Science Council (Taiwan) for financial support (NSC 96-2314-B-002-022-MY3).
Purpose: This study aimed to evaluate the effects of exercise training and IMT on apnea-hypopnea index (AHI) and cardiopulmonary capacity in patients with severe OSA.
Methods: This is a randomized controlled study with 52 patients diagnosed with severe OSA by polysomnography (PSG) divided into four groups: exercise training (Ex: n =15), IMT (IMT: n =13), CPAP (CPAP, n=13), and control group (CN, n=11). Each exercise training program consisted of 50 minutes of aerobic exercise training at moderate intensity (60%-80% peak oxygen uptake, VO2peak), three times a week for 12 weeks. The intensity of IMT started at 30% maximal inspiratory pressure for 12 weeks. The frequency for IMT is 15 min/ sessions, 2 sessions/day, 7 days per week. OSA severity was measured with one-night laboratory PSG before and following the 12-week intervention. All patients also received cardiopulmonary exercise test before and after intervention.
Results: Forty-one patients (78.8%) completed the intervention, and intention-to treat was used for data analysis. The results revealed a significant decrease of AHI (52.0±16.3 /h to 39.7±26.6 /h) in the exercise group compared to the IMT group (52.7±14.0 /h to 57.3±15.9 /h) after training (p 0.05). CPAP group and control group did not show significant changes of AHI after 12-week intervention (p>0.05). In addition, exercise group showed a significant improvement of VO2peak (mean difference of 1.99 mi/kg/min)compared to the other three groups (p 0.05).
Conclusion(s): Our results indicated that exercise training gained a significant improvement of AHI and cardiopulmonary capacity compared to the other treatments. However, 12 weeks of IMT could not improve AHI, and possibly aggravated the severity of OSA.
Implications: A significantly lower functional performance of inspiratory muscles of patients with OSA was shown because of repetitive inspiratory effort against an obstructed airway and intermittent hypoxia. IMT, which was meant to increase the strength of inspiratory muscles was shown to have adverse effects on the severity of OSA in this study. General aerobic exercise could be an alternative or complementary approach to existing therapies for OSA.
Keywords: Obstructive sleep apnea, inspiratory muscle training, apnea-hypopnea index
Funding acknowledgements: The authors thank the National Science Council (Taiwan) for financial support (NSC 96-2314-B-002-022-MY3).
Topic: Cardiorespiratory
Ethics approval required: Yes
Institution: National Taiwan University Hospital
Ethics committee: the Research Ethics Committee
Ethics number: NCT00813852
All authors, affiliations and abstracts have been published as submitted.
