Electrophysiologic changes with incremental exercise in obstructive sleep apnea

Authors

  • Meng-Yueh Chien PT, PhD,

    1. School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan, Taiwan
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  • Ya-Ju Chang PT, PhD,

    1. Department of Physical Therapy and Graduate Institute of Rehabilitation Science, and Healthy Aging Research Center, Chang Gung University, Tao-Yuan, Taiwan
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  • Peilin Lee MD, PhD,

    1. Division of Pulmonary Medicine and Critical Care in Department of Internal Medicine, and Center of Sleep Disorder, National Taiwan University Hospital, Taipei, Taiwan
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  • Pan-Chyr Yang MD, PhD,

    1. Division of Pulmonary Medicine and Critical Care in Department of Internal Medicine, and Center of Sleep Disorder, National Taiwan University Hospital, Taipei, Taiwan
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  • Ying-Tai Wu PT, PhD

    Corresponding author
    • School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan, Taiwan
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  • This study was supported by a grant from the National Science Council (Taiwan) (NSC 96-2314-B-002-022-MY3).

Correspondence to: Y.-T. Wu; e-mail: ytw@ntu.edu.tw

Abstract

Introduction

In patients with obstructive sleep apnea (OSA), intermittent apnea and hypopnea might cause different adaptations in inspiratory and peripheral muscles. In this study we aimed to determine the changes that occur in muscle activation characteristics during incremental exercise testing in patients with severe OSA. Surface electromyography of inspiratory muscles and knee extensors was performed.

Methods

Eleven men with severe OSA and 11 matched controls were recruited. Changes in muscle activity were compared by determining root mean square (RMS) and median power frequency (MPF) values obtained at different exercise intensities.

Results

The ratios of RMS to oxygen consumption in inspiratory muscles and vastus lateralis increased significantly at peak workload in the control group (P < 0.05), but not in the OSA group.

Conclusions

Patients with severe OSA demonstrated an inability to increase motor unit recruitment of inspiratory muscles and knee extensors during incremental exercise. Muscle Nerve, 48: 212–218, 2013

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