Central chemoreflex sensitivity and sympathetic neural outflow in elite breath-hold divers

Zeljko Dujic, Vladimir Ivancev, Karsten Heusser, Gordan Dzamonja, Ivan Palada, Zoran Valic, Jens Tank, Ante Obad, Darija Bakovic, Andre Diedrich, Michael Joseph Joyner, Jens Jordan

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Repeated hypoxemia in obstructive sleep apnea patients increases sympathetic activity, thereby promoting arterial hypertension. Elite breath-holding divers are exposed to similar apneic episodes and hypoxemia. We hypothesized that trained divers would have increased resting sympathetic activity and blood pressure, as well as an excessive sympathetic nervous system response to hypercapnia. We recruited 11 experienced divers and 9 control subjects. During the diving season preceding the study, divers participated in 7.3 ± 1.2 diving fish-catching competitions and 76.4 ± 14.6 apnea training sessions with the last apnea 3-5 days before testing. We monitored beat-by-beat blood pressure, heart rate, femoral artery blood flow, respiration, end-tidal CO2, and muscle sympathetic nerve activity (MSNA). After a baseline period, subjects began to rebreathe a hyperoxic gas mixture to raise end-tidal CO2 to 60 Torr. Baseline MSNA frequency was 31 ± 11 bursts/min in divers and 33 ± 13 bursts/min in control subjects. Total MSNA activity was 1.8 ± 1.5 AU/min in divers and 1.8 ± 1.3 AU/min in control subjects. Arterial oxygen saturation did not change during rebreathing, whereas end-tidal CO2 increased continuously. The slope of the hypercapnic ventilatory and MSNA response was similar in both groups. We conclude that repeated bouts of hypoxemia in elite, healthy breath-holding divers do not lead to sustained sympathetic activation or arterial hypertension. Repeated episodes of hypoxemia may not be sufficient to drive an increase in resting sympathetic activity in the absence of additional comorbidities.

Original languageEnglish (US)
Pages (from-to)205-211
Number of pages7
JournalJournal of Applied Physiology
Volume104
Issue number1
DOIs
StatePublished - Jan 2008

Fingerprint

Breath Holding
Diving
Apnea
Muscles
Blood Pressure
Hypertension
Respiratory Muscles
Hypercapnia
Sympathetic Nervous System
Obstructive Sleep Apnea
Femoral Artery
Comorbidity
Respiration
Fishes
Heart Rate
Gases
Oxygen
Hypoxia

Keywords

  • Apnea
  • Human
  • Muscle sympathetic nerve activity
  • Ultrasound

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Dujic, Z., Ivancev, V., Heusser, K., Dzamonja, G., Palada, I., Valic, Z., ... Jordan, J. (2008). Central chemoreflex sensitivity and sympathetic neural outflow in elite breath-hold divers. Journal of Applied Physiology, 104(1), 205-211. https://doi.org/10.1152/japplphysiol.00844.2007

Central chemoreflex sensitivity and sympathetic neural outflow in elite breath-hold divers. / Dujic, Zeljko; Ivancev, Vladimir; Heusser, Karsten; Dzamonja, Gordan; Palada, Ivan; Valic, Zoran; Tank, Jens; Obad, Ante; Bakovic, Darija; Diedrich, Andre; Joyner, Michael Joseph; Jordan, Jens.

In: Journal of Applied Physiology, Vol. 104, No. 1, 01.2008, p. 205-211.

Research output: Contribution to journalArticle

Dujic, Z, Ivancev, V, Heusser, K, Dzamonja, G, Palada, I, Valic, Z, Tank, J, Obad, A, Bakovic, D, Diedrich, A, Joyner, MJ & Jordan, J 2008, 'Central chemoreflex sensitivity and sympathetic neural outflow in elite breath-hold divers', Journal of Applied Physiology, vol. 104, no. 1, pp. 205-211. https://doi.org/10.1152/japplphysiol.00844.2007
Dujic, Zeljko ; Ivancev, Vladimir ; Heusser, Karsten ; Dzamonja, Gordan ; Palada, Ivan ; Valic, Zoran ; Tank, Jens ; Obad, Ante ; Bakovic, Darija ; Diedrich, Andre ; Joyner, Michael Joseph ; Jordan, Jens. / Central chemoreflex sensitivity and sympathetic neural outflow in elite breath-hold divers. In: Journal of Applied Physiology. 2008 ; Vol. 104, No. 1. pp. 205-211.
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