UBC-Nepal expedition: markedly lower cerebral blood flow in high-altitude Sherpa children compared with children residing at sea level

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Author
Fluck, Daniela
Morris, Laura
Niroula, Shailesh
Tallon, Christine
Sherpa, Kami T.
Stembridge, Mike
Ainslie, Philip
McManus, Ali
Date
2017-10-01Acceptance date
2017-05-30
Type
Article
Publisher
American Physiological Society
ISSN
1522-1601
Metadata
Show full item recordAbstract
Developmental cerebral hemodynamic adaptations to chronic high-altitude exposure, such as in the Sherpa population, are largely unknown. To examine hemodynamic adaptations in the developing human brain, we assessed common carotid (CCA), internal carotid (ICA), and vertebral artery (VA) flow and middle cerebral artery (MCA) velocity in 25 (9.6 ± 1.0 yr old, 129 ± 9 cm, 27 ± 8 kg, 14 girls) Sherpa children (3,800 m, Nepal) and 25 (9.9 ± 0.7 yr old, 143 ± 7 cm, 34 ± 6 kg, 14 girls) age-matched sea level children (344 m, Canada) during supine rest. Resting gas exchange, blood pressure, oxygen saturation and heart rate were assessed. Despite comparable age, height and weight were lower (both P < 0.01) in Sherpa compared with sea level children. Mean arterial pressure, heart rate, and ventilation were similar, whereas oxygen saturation (95 ± 2 vs. 99 ± 1%, P < 0.01) and end-tidal Pco2 (24 ± 3 vs. 36 ± 3 Torr, P < 0.01) were lower in Sherpa children. Global cerebral blood flow was ∼30% lower in Sherpa compared with sea level children. This was reflected in a lower ICA flow (283 ± 108 vs. 333 ± 56 ml/min, P = 0.05), VA flow (78 ± 26 vs. 118 ± 35 ml/min, P < 0.05), and MCA velocity (72 ± 14 vs. 88 ± 14 cm/s, P < 0.01). CCA flow was similar between Sherpa and sea level children (425 ± 92 vs. 441 ± 81 ml/min, P = 0.52). Scaling flow and oxygen uptake for differences in vessel diameter and body size, respectively, led to the same findings. A lower cerebral blood flow in Sherpa children may reflect specific cerebral hemodynamic adaptations to chronic hypoxia.
Journal/conference proceeding
Journal of Applied Physiology;
Citation
Flück, D., Morris, L.E., Niroula, S., Tallon, C.M., Sherpa, K.T., Stembridge, M., Ainslie, P.N. and McManus, A.M., 2017. UBC-Nepal expedition: markedly lower cerebral blood flow in high-altitude Sherpa children compared with children residing at sea level. Journal of Applied Physiology, 123(4), pp.1003-1010.
Description
This article was published in Journal of Applied Physiology on 1 October 2017, available at https://doi.org/10.1152/japplphysiol.00292.2017
Sponsorship
Cardiff Metropolitan University (Grant ID: Cardiff Metropolian (Internal))
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- Sport Research Groups [1084]
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