Comparison of hemoglobin mass and concentration as well as blood plasma volume in more than 80 lowlanders, lowlanders adapted to high altitude, Sherpa highland natives from Nepal, and Andean Quechua natives from Peru revealed that the relatively low blood hemoglobin concentration of Sherpas--a trait tied to reproductive success and exercise capacity--is the result of relatively high plasma volume, rather than restricted hemoglobin production, as previously thought; the findings suggest that Sherpas increase their oxygen carrying capacity at high altitude, but keep their blood viscosity low by increasing plasma volume, and that this feature, absent in Andeans, may underlie Sherpas' adaptation to high altitude.
###
Article #19-09002: " The overlooked significance of plasma volume for successful adaptation to high altitude in Sherpa and Andean natives," by Mike Stembridge et al.
MEDIA CONTACT: Mike Stembridge, Cardiff Metropolitan University, Cardiff, UNITED KINGDOM; e-mail: mstembridge@cardiffmet.ac.uk
Proceedings of the National Academy of Sciences