title: Increased blood-oxygen binding affinity in Tibetan and Han Chinese residents at 4200 m.
abstract: High-altitude natives are challenged by hypoxia, and a potential compensatory mechanism could be reduced blood oxygen-binding affinity (P50), as seen in several high-altitude mammalian species. In 21 Qinghai Tibetan and nine Han Chinese men, all resident at 4200 m, standard P50 was calculated from measurements of arterial PO2 and forehead oximeter oxygen saturation, which was validated in a separate examination of 13 healthy subjects residing at sea level. In both Tibetans and Han Chinese, standard P50 was 24.5 ± 1.4 and 24.5 ± 2.0 mmHg, respectively, and was lower than in the sea-level subjects (26.2 ± 0.6 mmHg, P < 0.01). There was no relationship between P50 and haemoglobin concentration (the latter ranging from 15.2 to 22.9 g dl(-1) in Tibetans). During peak exercise, P50 was not associated with alveolar-arterial PO2 difference or peak O2 uptake per kilogram. There appears to be no apparent benefit of a lower P50 in this adult high-altitude Tibetan population.
authors.affiliation: Department of Medicine, Division of Physiology, University of California, San Diego, La Jolla, CA, 92093, USA tsimonson@ucsd.edu.
authors.forename: T S
authors.initials: TS
authors.lastname: Simonson
authors.affiliation: Research Center for High-Altitude Medicine, Qinghai Medical College, Xining, Qinghai, 810001, PR China.
authors.forename: G
authors.initials: G
authors.lastname: Wei
authors.affiliation: Department of Medicine, Division of Physiology, University of California, San Diego, La Jolla, CA, 92093, USA.
authors.forename: H E
authors.initials: HE
authors.lastname: Wagner
authors.affiliation: Research Center for High-Altitude Medicine, Qinghai Medical College, Xining, Qinghai, 810001, PR China.
authors.forename: T
authors.initials: T
authors.lastname: Wuren
authors.affiliation: Department of Medicine, Division of Physiology, University of California, San Diego, La Jolla, CA, 92093, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bui
authors.affiliation: Department of Medicine, Division of Physiology, University of California, San Diego, La Jolla, CA, 92093, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Fine
authors.affiliation: Research Center for High-Altitude Medicine, Qinghai Medical College, Xining, Qinghai, 810001, PR China.
authors.forename: G
authors.initials: G
authors.lastname: Qin
authors.affiliation: Exercise Research Laboratory, School of Physical Education, Federal University of Rio Grande do Sul, RS, Brazil.
authors.forename: F G
authors.initials: FG
authors.lastname: Beltrami
authors.affiliation: Research Center for High-Altitude Medicine, Qinghai Medical College, Xining, Qinghai, 810001, PR China.
authors.forename: M
authors.initials: M
authors.lastname: Yan
authors.affiliation: Department of Medicine, Division of Physiology, University of California, San Diego, La Jolla, CA, 92093, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: Wagner
authors.affiliation: Research Center for High-Altitude Medicine, Qinghai Medical College, Xining, Qinghai, 810001, PR China.
authors.forename: Ri Li
authors.initials: RL
authors.lastname: Ge
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D001784:Blood Gas Analysis; D002681:China; D015444:Exercise; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D008297:Male; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*; D018609:Tibet; D055815:Young Adult
chemical_list: D010100:Oxygen