UBC-Nepal expedition: The use of oral antioxidants does not alter cerebrovascular function at sea-level or high-altitude

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Author
Hansen, Alex B.
Hoiland, Ryland L.
Lewis, Nia C. S.
Tymko, Michael M.
Tremblay, Joshua C.
Stembridge, Mike
Nowak-Fluck, Daniela
Carter, Howard H.
Bailey, Damian M.
Ainslie, Philip
Date
2018-02-10Acceptance date
2018-02-05
Type
Article
Publisher
Wiley
ISSN
0958-0670
1469-445X (ESSN)
Metadata
Show full item recordAbstract
Hypoxia is associated with an increased systemic and cerebral formation of free radicals and associated reactants that may be linked to impaired cerebral vascular function a neurological sequela. To what extent oral antioxidants prophylaxis impacts cerebrovascular function in humans throughout the course of acclimatization to the hypoxia of terrestrial high-altitude has not been examined. Thus, the purpose of the current study was to examine the influence of orally ingested antioxidants at clinically relevant doses (vitamin C, E, and alpha-lipoic acid) on cerebrovascular regulation at sea-level (344 m; n = 12; female n = 2 participants), and at high altitude (5050 m; n = 9; female n = 2), in a randomized, placebo-controlled, and double-blinded crossover design. Hypercapnic and hypoxic cerebrovascular reactivity tests of the internal carotid (ICA)] were conducted at sea-level, while global and regional cerebral blood flow [i.e. ICA and vertebral artery (VA)] were assessed after 10–12 days following arrival at 5050 m. At sea-level, acute administration of antioxidants did not alter cerebral hypoxic cerebrovascular reactivity (pre vs. post: 1.5 ± 0.7 vs. 1.2 ± 0.8 %∆CBF/-%∆SpO2; P = 0.96), or cerebral hypercapnic cerebrovascular reactivity (pre vs. post: 5.7 ± 2.0 vs. 5.8 ± 1.9 %∆CBF/∆mmHg; P = 0.33). Furthermore, global cerebral blood flow (P = 0.43), as well as cerebral vascular conductance (ICA P = 0.08; VA P = 0.32), were unaltered at 5050 m following antioxidant administration. In conclusion, these data show that an oral antioxidant cocktail known to attenuate systemic oxidative stress failed to alter cerebrovascular function at sea-level and cerebral blood flow during acclimatization to high-altitude.
Journal/conference proceeding
Experimental Physiology;
Citation
Hansen, A.B., Hoiland, R.L., Lewis, N., Tymko, M.M., Tremblay, J.C., Stembridge, M., Nowak‐Flück, D., Carter, H.H., Bailey, D.M. and Ainslie, P.N. (2018) 'UBC‐Nepal expedition: The use of oral antioxidants does not alter cerebrovascular function at sea‐level or high‐altitude', Experimental Physiology. https://doi.org/10.1113/EP086887
Description
This article was published in Experimental Physiology on 10 February 2018 (online), available at https://doi.org/10.1113/EP086887
Sponsorship
Cardiff Metropolitan University (Grant ID: Cardiff Metropolian (Internal))
Collections
- Sport Research Groups [1089]
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