1. Second generation Tibetan lowlanders acclimatize to high altitude more quickly than Caucasians.
- Author
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Marconi, Claudio, Marzorati, Mauro, Grassi, Bruno, Basnyat, Buddha, Colombini, Angelo, Kayser, Bengt, and Cerretelli, Paolo
- Subjects
TIBETANS ,ALTITUDES ,RESPIRATION ,SHERPA (Nepalese people) ,CAUCASIAN race - Abstract
Tibetan highlanders develop at altitude peak aerobic power levels (V
O 2peak ) close to those of Caucasians at sea level. In order to establish whether this feature is genetic and, as a consequence, retained by Tibetan lowlanders, altitude-induced changes of peak aerobic performance (Δ VO 2peak ) were assessed in four groups of volunteers with different ethnic, altitude exposure and fitness characteristics, i.e. eight untrained second-generation Tibetans (Tib 2) born and living at 1300 m; seven altitude Sherpas living at ∼2800-3500 m; and 10 untrained and five trained Caucasians. Measurements were carried out at sea level or at Kathmandu (1300 m, Nepal) (PRE), and after 2-4 (ALT1),14-16 (ALT2), and 26-28 (ALTS) days at 5050 m. At ALTS, Δ VO 2peak of \ untrained and trained Caucasians was -31% and -46%, respectively. By contrast, Δ VO 2peak of Tib 2 and Sherpas was -8% and -15%, respectively. At ALTS, peak heart rate (HRpeak ) of untrained and trained Caucasians was 148 ± 11 and 149 ± 7 beats min-1 , respectively; blood oxygen saturation at peak exercise ( SaO 2peak ) was 76 ± 6% and 73 ± 6%, and haemoglobin concentration ([Hb]) was 19.4 ± 1.0 and 18.6 ± 1.2 g dl-1 , respectively. Compared to Caucasians, Tib 2 and Sherpas exhibited at ALTS higher HRpeak (179 ± 9 and 171 ± 4 beats min-1 , P < 0.001), lower [Hb] (16.6 ± 0.6 and 17.4 ± 0.9 g dl-1 , respectively, P < 0.001), and slightly but non-significantly greater average SaO 2peak values (82 ± 6 and 80 ± 7%). The above findings and the time course of adjustment of the investigated variables suggest that Tibetan lowlanders acclimatize to chronic hypoxia more quickly than Caucasians,... [ABSTRACT FROM AUTHOR]- Published
- 2004
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