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Experimental Physiology - 2022 - Subedi - Pulmonary vascular reactivity to supplemental oxygen in Sherpa and lowlanders.pdf (595.27 kB)
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Pulmonary vascular reactivity to supplemental oxygen in Sherpa and lowlanders during gradual ascent to high altitude

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posted on 2022-11-25, 14:32 authored by Prajan Subedi, Christopher Gasho, Michael StembridgeMichael Stembridge, Alexandra M. Williams, Alexander Patrician, Philip N. Ainslie, James Anholm

 Prolonged alveolar hypoxia leads to pulmonary vascular remodelling. We examined the time course at altitude, over which hypoxic pulmonary vasoconstriction goes from being acutely reversible to potentially irreversible. Study subjects were lowlanders (n = 20) and two Sherpa groups. All Sherpa were born and raised at altitude. One group (ascent Sherpa, n = 11) left altitude and after de-acclimatization in Kathmandu for ∼7 days re-ascended with the lowlanders over 8–10 days to 5050 m. The second Sherpa group (non-ascent Sherpa, n = 12) remained continuously at altitude. Pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR) were measured while breathing ambient air and following supplemental oxygen. During ascent PASP and PVR increased in lowlanders and ascent Sherpa; however, with supplemental oxygen, lowlanders had significantly greater decrease in PASP (P = 0.02) and PVR (P = 0.02). After ∼14 days at 5050 m, PASP decreased with supplemental oxygen (mean decrease: 3.9 mmHg, 95% CI 2.1–5.7 mmHg, P < 0.001); however, PVR was unchanged (P = 0.49). In conclusion, PASP and PVR increased with gradual ascent to altitude and decreased via oxygen supplementation in both lowlanders and ascent Sherpa. Following ∼14 days at 5050 m altitude, there was no change in PVR to hypoxia or O2 supplementation in lowlanders or either Sherpa group. These data show that both duration of exposure and residential altitude influence the pulmonary vascular responses to hypoxia. 

History

Published in

Experimental Physiology

Publisher

Wiley

Version

  • VoR (Version of Record)

Citation

Subedi, P., Gasho, C., Stembridge, M., Williams, A.M., Patrician, A., Ainslie, P.N. and Anholm, J.D. (2022) 'Pulmonary vascular reactivity to supplemental oxygen in Sherpa and lowlanders during gradual ascent to high altitude', Experimental Physiology. DOI: 10.1113/EP090458

Print ISSN

0958-0670

Electronic ISSN

1469-445X

Cardiff Met Affiliation

  • Cardiff School of Sport and Health Sciences

Cardiff Met Authors

Mike Stembridge

Cardiff Met Research Centre/Group

  • Cardiovascular Physiology

Copyright Holder

  • © The Authors

Language

  • en