Alterations in autonomic cardiac modulation in response to normobaric hypoxia

2.50
Hdl Handle:
http://hdl.handle.net/10545/621062
Title:
Alterations in autonomic cardiac modulation in response to normobaric hypoxia
Authors:
Giles, David ( 0000-0002-5590-5734 ) ; Kelly, John; Draper, Nick ( 0000-0002-4466-3792 )
Abstract:
Purpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% FIO2). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnRMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO2 occurred with reduced FIO2, along with a rise in heart rate (Cohen’s d = 1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% FIO2. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% FIO2) decrease in lnTP (d = 1.84 [1.74–1.94]), and SampEn (d = 0.98 [0.83–1.12]) and an increase in DFA-α1 (d = 0.72 [0.60–0.84]) from normoxia at 9.8% FIO2. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ∼9.8% FIO2 (∼6000 m equiv.), below which significant alterations in autonomic control occur.
Affiliation:
University of Derby
Citation:
Giles, D. et al (2016) 'Alterations in autonomic cardiac modulation in response to normobaric hypoxia', European Journal of Sport Science, 16 (8):1023
Publisher:
Taylor and Francis
Journal:
European Journal of Sport Science
Issue Date:
2016
URI:
http://hdl.handle.net/10545/621062
DOI:
10.1080/17461391.2016.1207708
Additional Links:
https://www.tandfonline.com/doi/full/10.1080/17461391.2016.1207708
Type:
Article
Language:
en
ISSN:
1746-1391
EISSN:
1536-7290
Appears in Collections:
Department of Life Sciences

Full metadata record

DC FieldValue Language
dc.contributor.authorGiles, Daviden
dc.contributor.authorKelly, Johnen
dc.contributor.authorDraper, Nicken
dc.date.accessioned2016-11-25T10:07:55Z-
dc.date.available2016-11-25T10:07:55Z-
dc.date.issued2016-
dc.identifier.citationGiles, D. et al (2016) 'Alterations in autonomic cardiac modulation in response to normobaric hypoxia', European Journal of Sport Science, 16 (8):1023en
dc.identifier.issn1746-1391-
dc.identifier.doi10.1080/17461391.2016.1207708-
dc.identifier.urihttp://hdl.handle.net/10545/621062-
dc.description.abstractPurpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% FIO2). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnRMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO2 occurred with reduced FIO2, along with a rise in heart rate (Cohen’s d = 1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% FIO2. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% FIO2) decrease in lnTP (d = 1.84 [1.74–1.94]), and SampEn (d = 0.98 [0.83–1.12]) and an increase in DFA-α1 (d = 0.72 [0.60–0.84]) from normoxia at 9.8% FIO2. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ∼9.8% FIO2 (∼6000 m equiv.), below which significant alterations in autonomic control occur.en
dc.language.isoenen
dc.publisherTaylor and Francisen
dc.relation.urlhttps://www.tandfonline.com/doi/full/10.1080/17461391.2016.1207708en
dc.rightsArchived with thanks to European Journal of Sport Scienceen
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en
dc.subjectNormobaric hypoxiaen
dc.subjectAutonomic nervous systemen
dc.subjectHeart rate variabilityen
dc.subjectSample entropyen
dc.titleAlterations in autonomic cardiac modulation in response to normobaric hypoxiaen
dc.typeArticleen
dc.identifier.eissn1536-7290-
dc.contributor.departmentUniversity of Derbyen
dc.identifier.journalEuropean Journal of Sport Scienceen
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