Exercise performance of Tibetan and Han adolescents at altitudes of 3,417 and 4,300 m

Abstract

Yoshimura. Exercise performance of Tibetan and Han adolescents at altitudes of 3,417 and 4,300 m. J. Appl. Physiol. 83(2): 661-667, 1997.-The difference was studied between O 2 transport in lifelong Tibetan adolescents and in newcomer Han adolescents acclimatized to high altitude. We measured minute ventilation, maximal O 2 uptake, maximal cardiac output, and arterial O 2 saturation during maximal exercise, using the incremental exercise technique, at altitudes of 3,417 and 4,300 m. The groups were well matched for age, height, and nutritional status. The Tibetans had been living at the altitudes for a longer period than the Hans (14.5 6 0.2 vs. 7.8 6 0.8 yr at 3,417 m, P , 0.01; and 14.7 6 0.3 vs. 5.3 6 0.7 yr at 4,300 m, P , 0.01, respectively). At rest, Tibetans had significantly greater vital capacity and maximal voluntary ventilation than the Hans at both altitudes. At maximal exercise, Tibetans compared with Hans had higher maximal O 2 uptake (42.2 6 1.7 vs. 36.7 6 1.2 ml · min 21 ·kg 21 at 3,417 m, P , 0.01; and 36.8 6 1.9 vs. 30.0 6 1.4 ml · min 21 ·kg 21 at 4,300 m, P , 0.01, respectively) and greater maximal cardiac output (12.8 6 0.3 vs. 11.4 6 0.2 l/min at 3,417 m, P , 0.01; 11.5 6 0.5 vs. 10.0 6 0.5 l/min at 4,300 m, P , 0.05, respectively). Although the differences in arterial O 2 saturation between Tibetans and Hans were not significant at rest and during mild exercise, the differences became greater with increases in exercise workload at both altitudes. We concluded that exposure to high altitude from birth to adolescence resulted in an efficient O 2 transport and a greater aerobic exercise performance that may reflect a successful adaptation to life at high altitude. cardiac output; maximal oxygen consumption; ventilation; developmental adaptation; genetic adaptation MAXIMAL O 2 UPTAKE (V O 2 max ), an integrated index of the overall functional capacity of the O 2 transport system, invariably decreases with altitude during both acute and chronic exposure to high altitude in lowland adults (31,34). This is due to the reduction of ambient O 2 pressure at high altitude. Although comparative studies of V O 2 max between high altitude natives and lowland residents at high-altitude have been done, the conclusions are controversial (10-13, 30). High-altitude adult natives in either Andean or Himalayan populations have higher exercise performance and maintain better arterial O 2 saturation (Sa O 2 ) during exercise compared with newcomers (17,20,30,38). These characteristics, which are associated with more efficient pulmonary gas exchange (38) and better adaptation to high-altitude stress, are acquired through many generations of lifelong high-altitude exposure. The Tibetans are believed to have lived at high altitude longer than other highaltitude residents. The effects of high-altitude hypoxia on the physiological responses of Tibetan and Han adolescents to exercise have never been reported. Whether the pulmonary adaptations in humans are determined purely by environment or relate to genetic character...

Correlation between single nucleotide polymorphisms in hypoxia-related genes and susceptibility to acute high-altitude pulmonary edema

“…A very small portion of the people suffering from HAPE in the same population were observed to migrate to a plateau region (Rupert and Koehle, 2006). Tibetans show greater adaptability to the hypoxic environment of high-altitude regions compared to people belonging to the Han ethnicity; the incidence of HAPE was significantly less in Tibetans compared to that observed in people belonging the Han ethnicity (Cheng et al, 1997;Basu et al, 2007). Genetic factors accounted for approximately 50% of the factors influencing the adaptation of the human body to highaltitude hypoxic environments (Wu et al, 2005;Wu and Kayser, 2006).…”

Pulmonary Vascular Disease in the Developing World

“…Exposure to high altitude from birth to adolescence results in changes in the oxygen transport system, so that a greater aerobic exercise performance is needed to reflect a successful adaptation to life at high altitude. 84 Remodeling of the pulmonary vessels suggests incomplete adaptation that is compatible with normal life at high altitude 85 and can be a significant health problem in these parts of the world. There is, however, considerable variation in susceptibility to hypoxia-induced pulmonary hypertension among different ethnic groups adapted to life at high altitude, which suggests genetic factors.…”

Angiotensin converting enzyme insertion allele in relation to high altitude adaptation

“…However, long-term inCorrespondence : Dr Qadar Pasha, Centre for Biochemical Technology, Delhi University Campus, Mall Road, Delhi-110007, India. Fax : j91 11 7667471 ; E-mail : qpasha!cbt.res.in habitants of HA ( 3000 m) demonstrate improvement in endurance performance (Chen et al 1997), due to a process of adaptation, which enables large communities to settle in mountainous areas (Hochachka et al 1996). During the last few decades, a significant amount of work has been done to understand the human biology of HA adaptation and disorders (Mirrakhimov & Winslow, 1996 ;Semenza, 1999 ;Lahiri, 2000).…”