Global REACH 2018: Renal oxygen delivery is maintained during early acclimatization to 4330 m

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Author
Steele, Andrew
Tymko, Michael
Meah, Victoria L.
Simpson, Lydia
Gasho, Christopher
Dawkins, Tony
Villafuerte, Francisco
Ainslie, Philip N.
Stembridge, Mike
Moore, Jonathan P.
Steinback, Craig D.
Date
2020-09-30Acceptance date
2020-09-27
Type
Article
Publisher
American Physiological Society
ISSN
1931-857X
Embargoed until
2021-09-30
Metadata
Show full item recordAbstract
Early acclimatization to high-altitude is characterized by various respiratory, hematological, and cardiovascular adaptations that serve to restore oxygen delivery to tissue. However, less is understood about renal function and the role of renal oxygen delivery (RDO2) during high altitude acclimatization. We hypothesized that: 1) RDO2 would be reduced after 12-hours of
high-altitude exposure (high-altitude day1) but restored to sea-level values after one-week (high altitude day7); and 2) RDO2 would be associated with renal reactivity (RR), an index of acid base compensation at high-altitude. Twenty-four healthy lowlander participants were tested at sea-level (344m; Kelowna, Canada), on day1 and day7 at high-altitude (4330m; Cerro de Pasco,
Peru). Cardiac output, renal blood flow, arterial and venous blood sampling for renin angiotensin-aldosterone-system hormones and NT pro-B type natriuretic peptides were collected at each time point. RR was calculated as: (Δ arterial bicarbonate)/(Δ partial pressure of arterial carbon dioxide) between sea-level and high-altitude day1, and sea-level and high-altitude day7.
The main findings were: 1) RDO2 was initially decreased at high-altitude compared to sea-level (ΔRDO2: -22±17%, P<0.001), but was restored to sea-level values on high-altitude day7 (ΔRDO2: -6±14%, P=0.36). The observed improvements in RDO2 resulted from both changes in renal blood flow (Δ from high-altitude day1: +12±11%; P=0.008), and arterial oxygen content (Δ
from high-altitude day1 +44.8±17.7%; P=0.006); and 2) RR was positively correlated with RDO2 on high-altitude day7 (r=0.70; P<0.001), but not high-altitude day1 (r=0.26; P=0.29).
These findings characterize the temporal responses of renal function during early high-altitude acclimatization, and the influence of RDO2 in the regulation of acid-base.
Journal/conference proceeding
American Journal of Physiology - Renal Physiology;
Citation
Steele, A.R., Tymko, M.M., Meah, V.L., Simpson, L.L., Gasho, C., Dawkins, T.G., Villafuerte, F.C., Ainslie, P.N., Stembridge, M., Moore, J.P. and Steinback, C.D. (2020) 'Global REACH 2018: Renal oxygen delivery is maintained during early acclimatization to 4330 m', American Journal of Physiology-Renal Physiology.https://doi.org/10.1152/ajprenal.00372.2020
Description
Article published in American Journal of Physiology - Renal Physiology, available at https://doi.org/10.1152/ajprenal.00372.2020
Sponsorship
Cardiff Metropolitan University (Grant ID: Cardiff Metropolian (Internal))
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- Sport Research Groups [1096]
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