Genioglossal activation in patients with obstructive sleep apnea versus control subjects. Mechanisms of muscle control

Am J Respir Crit Care Med. 2001 Dec 1;164(11):2025-30. doi: 10.1164/ajrccm.164.11.2102048.


Pharyngeal dilator muscle activation (GGEMG) during wakefulness is greater in patients with obstructive sleep apnea (OSA) than in healthy control subjects, representing a neuromuscular compensatory mechanism for a more collapsible airway. As previous work from our laboratory has demonstrated a close relationship between GGEMG and epiglottic pressure, we examined the relationship between genioglossal activity and epiglottic pressure in patients with apnea and in control subjects across a wide range of epiglottic pressures during basal breathing, negative-pressure (iron-lung) ventilation, heliox breathing, and inspiratory resistive loading. GGEMG was greater in the patients with apnea under all conditions (p < 0.05 for all comparisons), including tonic, phasic, and peak phasic GGEMG. In addition, patients with apnea generated a greater peak epiglottic pressure on a breath-by-breath basis. Although the relationship between GGEMG and epiglottic negative pressure was tight across all conditions in both groups (all R values > = 0.69), there were no significant differences in the slope of this relationship between the two groups (all p values > 0.30) under any condition. Thus, the increased GGEMG seen in the patient with apnea during wakefulness appears to be a product of an increased tonic activation of the muscle, combined with increased negative-pressure generation during inspiration.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Airway Resistance / physiology
  • Analysis of Variance
  • Case-Control Studies
  • Electromyography
  • Epiglottis / physiology
  • Epiglottis / physiopathology
  • Helium / pharmacology
  • Humans
  • Male
  • Middle Aged
  • Oxygen / pharmacology
  • Peak Expiratory Flow Rate
  • Pharyngeal Muscles / physiology*
  • Pharyngeal Muscles / physiopathology*
  • Respiratory Mechanics
  • Severity of Illness Index
  • Sleep Apnea, Obstructive / classification
  • Sleep Apnea, Obstructive / diagnosis
  • Sleep Apnea, Obstructive / physiopathology*
  • Tongue / physiology*
  • Tongue / physiopathology*
  • Ventilators, Negative-Pressure


  • Helium
  • heliox
  • Oxygen