Vagal activity and oxygen saturation response to hypoxia: Effects of aerobic fitness and rating of hypoxia tolerance

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15510%2F17%3A73581620" target="_blank" >RIV/61989592:15510/17:73581620 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.5507/ag.2017.014" target="_blank" >http://dx.doi.org/10.5507/ag.2017.014</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5507/ag.2017.014" target="_blank" >10.5507/ag.2017.014</a>

Result language

angličtina

Original language name

Vagal activity and oxygen saturation response to hypoxia: Effects of aerobic fitness and rating of hypoxia tolerance

Original language description

Background: A reduction in the inspired oxygen fraction (FiO2) induces a decline in arterial oxygen saturation (SpO2) and changes of heart rate variability (HRV). It has been shown that SpO2 and HRV responses to similar levels of acute normobaric hypoxia are inter-individual variable. Variable response may be influenced by normoxia reached maximal oxygen uptake (VO2max) value. Objective: The primary aim was to assess HRV and the SpO2 response to hypoxia, and examine the association with normoxic VO2max. Methods: Supine HRV and SpO2 were monitored during normobaric hypoxia (FiO2 = 9.6%) for 10 minutes in 28 subjects, aged 23.7 ± 1.7 years. HRV was evaluated by using both spectral and time domain HRV analysis. Low frequency (LF, 0.05-0.15 Hz) and high frequency (HF, 0.15-0.50 Hz) power together with square root of the mean of the squares of the successive differences (rMSSD) were calculated and transformed by natural logarithm (Ln). Based on the SpO2 in hypoxia, subjects were divided into Resistant (RG, SpO2 ≥ 70.9%, n = 14) and Sensitive (SG, SpO2 &lt; 70.9%, n = 14) groups. Perceived hypoxia tolerance was self-scored on a 4-level scale. Results: VO2max was higher in SG (62.4 ± 7.2 ml ⋅ kg-1 ⋅ min-1) compared with RG (55.5 ± 7.1 ml ⋅ kg-1 ⋅ min-1, p = .017, d = 0.97). A significant relationship (r = -.45, p = .017) between hypoxic-normoxic difference in SpO2 and normoxic VO2max level was found. Vagal activity (Ln rMSSD) was significantly decreased (SG: p &lt; .001, d = 2.64; RG: p &lt; .001, d = 1.22), while sympathetic activity (Ln LF/HF) was relatively increased (p &lt; .001, d = -1.40) in only the SG during hypoxia. Conclusions: Results show that subjects with a higher aerobic capacity exhibited a greater decline in SpO2, accompanied by greater autonomic cardiac disturbances during hypoxia. The SpO2 reduction was associated with perceived hypoxia comfort/discomfort. The hypoxia discomfort state was accompanied by a greater withdrawal in cardiac vagal activity.

Czech name

—

Czech description

—

Type

J_SC - Article in a specialist periodical, which is included in the SCOPUS database

CEP classification

—

OECD FORD branch

30306 - Sport and fitness sciences

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Acta Gymnica

ISSN

2336-4912

e-ISSN

—

Volume of the periodical

47

Issue of the periodical within the volume

3

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

10

Pages from-to

112-121

UT code for WoS article

—

EID of the result in the Scopus database

2-s2.0-85031090221