Hypoxia-mediated prolonged elevation of sympathetic nerve activity after periods of intermittent hypoxic apnea

Michael J. Cutler, Nicolette Muenter Swift, David M. Keller, Wendy L. Wasmund, Michael L. Smith

Research output: Contribution to journalArticle

99 Scopus citations

Abstract

Obstructive sleep apnea (OSA) is associated with transient elevation of muscle sympathetic nerve activity (MSNA) during apneic events, which often produces elevated daytime MSNA in OSA patients. Hypoxia is postulated to be the primary stimulus for elevated daytime MSNA in OSA patients. Therefore, we studied the effects of 20 min of intermittent voluntary hypoxic apneas on MSNA during 180 min of recovery. Also, we compared MSNA during recovery after either 20 min of intermittent voluntary hypoxic apneas, hypercapnic hypoxia, or isocapnic hypoxia. Consistent with our hypothesis, both total MSNA and MSNA burst frequency were elevated after 20 min of intermittent hypoxic apnea compared with baseline (P < 0.05). Both total MSNA and MSNA burst frequency remained elevated throughout the 180-min recovery period and were statistically different from time control subjects throughout this period (P < 0.05). Finally, MSNA during recovery from intermittent hypoxic apnea, hypercapnic hypoxia, and isocapnic hypoxia were not different (P = 0.50). Therefore, these data support the hypothesis that short-term exposure to intermittent hypoxic apnea results in sustained elevation of MSNA and that hypoxia is the primary mediator of this response.

Original languageEnglish
Pages (from-to)754-761
Number of pages8
JournalJournal of Applied Physiology
Volume96
Issue number2
DOIs
StatePublished - 1 Feb 2004

Keywords

  • Intermittent hypoxia
  • Obstructive sleep apnea

Fingerprint Dive into the research topics of 'Hypoxia-mediated prolonged elevation of sympathetic nerve activity after periods of intermittent hypoxic apnea'. Together they form a unique fingerprint.

  • Cite this