The overlooked significance of plasma volume for successful adaptation to high altitude in Sherpa and Andean natives

View/ open
Author
Stembridge, Mike
Williams, Alexandra M.
Gasho, Christopher
Dawkins, Tony
Drane, Aimee L.
Villafuerte, Francisco C.
Levine, Benjamin D.
Shave, Rob
Ainslie, Philip N.
Date
2019-07-29Acceptance date
2019-07-10
Date Deposited
2019-07-18
Type
Article
Publisher
National Academy of Sciences
ISSN
0027-8424
1091-6490 (online)
Metadata
Show full item recordAbstract
In contrast to Andean natives, high altitude Tibetans present with a lower hemoglobin concentration that correlates with reproductive success and exercise capacity. Decades of physiological and genomic research have assumed that the lower hemoglobin concentration in Himalayan natives results from a blunted erythropoietic response to hypoxia (i.e. no increase in total hemoglobin mass). In contrast, herein we test the hypothesis that the lower hemoglobin concentration is the result of greater plasma volume, rather than an absence of increased hemoglobin production. We assessed hemoglobin mass, plasma volume and blood volume in lowlanders at sea level, lowlanders acclimatized to high altitude, Himalayan Sherpa and Andean Quechua, and explored the functional relevance of volumetric hematological measures to exercise capacity. Hemoglobin mass was highest in Andeans, but also elevated in Sherpa compared to lowlanders. Sherpa demonstrated a larger plasma volume than Andeans, resulting in a comparable total blood volume at a lower hemoglobin concentration. Hemoglobin mass was positively related to exercise capacity in lowlanders at sea level and Sherpa at high altitude, but not in Andean natives. Collectively, our findings demonstrate a unique adaptation in Sherpa that reorientates attention away from hemoglobin concentration and towards a paradigm where hemoglobin mass and plasma volume may represent phenotypes with adaptive significance at high altitude.
Journal/conference proceeding
Proceedings of the National Academy of Sciences;
Description
Article published in Proceedings of the National Academy of Sciences on 29 July 2019, available open access at: https://doi.org/10.1073/pnas.1909002116.
Sponsorship
Cardiff Metropolitan University (Grant ID: Cardiff Metropolian (Internal))
Collections
- Import [796]
Related items
Showing items related by title, author, subject and abstract.
-
Ventricular structure, function and mechanics at high altitude: chronic remodelling in Sherpa verses short-term lowlander adaptation.
Unknown author (American Physiological Society, 2014-08-01)Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged ... -
Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation.
Unknown author (American Physiological Society, 2014-08-01)Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged ... -
In vivo human cardiac shortening and lengthening velocity is region-dependent and not coupled with heart rate
Stembridge, Mike; Ainslie, Philip; Hughes, Michael G.; Stöhr, Eric J.; Cotter, James D.; Nio, Amanda Q. X.; Shave, Rob (American Physiological Society, 2015-05-01)Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged ...