Abstract
Conclusion: Variability of GGEMG at sleep onset is associated with apnea severity in OSA patients. At sleep onset, a lower decline in GGEMG might suggest a more severe OSA. Objective: The goal of this study was to evaluate genioglossus (GG) activation in the Chinese population at early sleep onset, and clarify the relationship of GG activation and the apnea severity in patients with Obstructive Sleep Apnea (OSA). Methods: Thirty-five OSA patients and 10 normal controls underwent overnight polysomnography with synchronous genioglossus electromyography (GGEMG) using intra-oral electrodes. The upper airway (UA) anatomy was evaluated by three-dimensional computer tomography (3D-CT) in all subjects. Results: The average GGEMG and tonic GGEMG were higher in the apnea patients than in the normal controls during wakefulness and early sleep onset period (three breaths) (p < 0.01). Eight OSA patients had increased GGEMG at sleep onset and 27 patients had decreased GGEMG values. Between the two groups, there were significant differences in the apnea-hypopnea index (AHI), minimal cross-sectional airway area (mCAS) and minimal lateral airway dimension (mLAT) at velopharynx (p < 0.05). The change in GGEMG, phasic GGEMG and tonic GGEMG from awake to sleep showed positive correlations with AHI and negative correlations with velopharynx (mLAT and mCAS) (p < 0.05).
Acknowledgments
The project was supported by the National Science Foundation of China (No. 81170902), the National Science Foundation of China (No. 81200735) and the National Science and Technology Support Plan (No. 2013BAI03B05). This was not an industry supported study. We thank the study participants as well as the technologists and physicians at the Sleep Centre of Beijing Tongren Hospital for their help with this study.
Declaration of interest
The authors declare that they have no conflict of interest. The authors alone are responsible for the content and writing of the paper.