Search

Forced vital capacity (FVC) and maximal exercise response were measured in two populations of Peruvian males (age, 18-35 years) at 4,338 m who differed by the environment in which they were born and raised, i.e., high altitude (Cerro de Pasco, Peru, BHA, n = 39) and sea level (Lima, Peru, BSL, n = 32). BSL subjects were transported from sea level to 4,338 m, and were evaluated within 24 hr of exposure to hypobaric hypoxia. Individual admixture level (ADMIX, % Spanish ancestry) was estimated for each subject, using 22 ancestry-informative genetic markers and also by skin reflectance measurement (MEL). Birthplace accounted for the ~10% larger FVC (P < 0.001), ~15% higher maximal oxygen consumption (V[O.sub.2]max, ml x [min.sup.-1] x [kg.sup.-1]) (P < 0.001), and ~5% higher arterial oxygen saturation during exercise (Sp[O.sub.2]) (P < 0.001) of BHA subjects. ADMIX was low in both study groups, averaging 9.5 [+ or -] 2.6% and 2.1 [+ or -] 0.3% in BSL and BHA subjects, respectively. Mean underarm MEL was significantly higher in the BSL group (P < 0.001), despite higher ADMIX. ADMIX was not associated with any study phenotype, but study power was not sufficient to evaluate hypotheses of genetic adaptation via the ADMIX variable. MEL and FVC were positively correlated in the BHA (P = 0.035) but not BSL (P = 0.335) subjects. However, MEL and ADMIX were not correlated across the entire study sample (P = 0.282). In summary, results from this study emphasize the importance of developmental adaptation to high altitude. While the MEL-FVC correlation may reflect genetic adaptation to high altitude, study results suggest that alternate (environmental) explanations be considered. KEY WORDS pulmonary; V[O.sub.2]max; arterial oxygen saturation; Andes; genetic markers; adaptation-hypoxia

Peak oxygen consumption (VO(sub 2) peak) was measured in 150 adult males (18-35 years old) in Bolivia, using a complete migrant study design to partition developmental from ancestral (genetic) effects of high-altitude (HA) exposure. High-altitude natives (HANs, Aymara/Quechua ancestry, n = 75) and low-altitude natives (LANs, European] North American ancestry, n = 75) were studied at high altitude (3,600-3,850 m) and near sea level (420 m). HAN and LAN migrant groups to a nonnative environment were classified as: multigeneration migrants, born and raised in a nonnative environment; child migrants who migrated to the nonnative environment during the period of growth and development (0-18 years old); and adult migrants who migrated after 18 years of age. Variability in VO(sub 2) peak due to high-altitude adaptation was modeled by covariance analysis, adjusting for fat-free mass and physical activity (training) differences between groups. A trend for increased VO(sub 2) peak with increasing developmental high-altitude exposure in migrant groups did not reach statistical significance, but low statistical power may have limited the ability to detect this effect. HANs and LANs born, raised, and tested at high altitude had similar VO(sub 2) peak values, indicating no genetic effect, or an effect much smaller than that reported previously in the literature. There was no functional correlation between forced vital capacity and VO(sub 2) peak, within or across groups. These results do not support the hypothesis that Andean HANs have been selected to express a greater physical work capacity in hypoxia. Am J Phys Anthropol 110:435-455, 1999. KEY WORDS: physical work capacity; human adaptation; Bolivia; exercise; migrant study design; physical activity level; hypoxia

Arterial oxygen saturation (Sa[O.sub.2]) was measured at 3,600-3,850 m by pulse oximetry at rest and during submaximal exercise in three study groups: 1) highland Aymara natives of the Bolivian altiplano (n = 25); 2) lowland European/North American sojourners to the highlands with at least 2 months of acclimatization time to 3,600 m (n = 27); and 3) subjects of European ancestry born and raised at 3,600 m (n = 22). Aymara subjects maintained ~1 percentage point higher Sa[O.sub.2] during submaximal work up to 70% of their maximal work capacity, and showed a smaller rate of decline in Sa[O.sub.2] with increasing work compared to both European study groups. The higher-exercise Sa[O.sub.2] of Aymara compared to Europeans born and raised at 3,600 m suggests genetic adaptation. The two European study groups, who differed by exposure to high altitude during their growth and development period, did not show any significant difference in either resting or exercise Sa[O.sub.2]. This suggests that the developmental mode of adaptation is less important than the genetic mode of adaptation in determining exercise Sa[O.sub.2]. A weak correlation was detected (across study groups only) between the residual forced vital capacity (FVC) and the residual Sa[O.sub.2] measured at the highest level of submaximal work output (P = 0.024, R = 0.26). While firm conclusions based on this correlation are problematic, it is suggested that a part of the higher Sa[O.sub.2] observed in Aymara natives is due to a larger lung volume and pulmonary diffusion capacity for oxygen. Results from this study are compared to similar studies conducted with Tibetan natives, and are interpreted in light of recent quantitative genetic analyses conducted in both the Andes and Himalayas. Am J Phys Anthropol 113:169-181, 2000. [C] 2000 Wiley-Liss, Inc. KEY WORDS hypoxia; Amerindian; lung diffusion capacity; developmental adaptation; genetic adaptation; Tibet

ABSTRACT High altitude natives are reported to have outstanding work capacity in spite of the challenge of oxygen transport and delivery in hypoxia. To evaluate the developmental effect of lifelong exposure to hypoxia on aerobic capacity, VO2peak was measured on two groups of Peruvian Quechua subjects (18-35 years), who differed in their developmental exposure to altitude. Male and female volunteers were recruited in Lima, Peru (150 m), and were divided in two groups, based on their developmental exposure to hypoxia, those: a) Born at sea-level individuals (BSL), with no developmental exposure to hypoxia ( n = 34) and b) Born at high-altitude individuals (BHA) with full developmental exposure to hypoxia ( n = 32), but who migrated to sea-level as adults (>16-years-old). Tests were conducted both in normoxia (BP = 750 mm Hg) and normobaric hypoxia at sea-level (BP = 750 mm Hg, FiO2 = 0.12, equivalent to 4,449 m), after a 2-month training period (in order to control for initial differences in physical fitness) at sea-level. BHA had a significantly higher VO2peak at hypoxia (40.31 ± 1.0 ml/min/kg) as compared to BSL (35.78 ± 0.96 ml/min/kg, P = 0.001), adjusting for sex. The decrease of VO2peak at HA relative to SL (ΔVO2peak) was not different between groups, controlling for baseline levels (VO2peak at sea-level) and sex (BHA = 0.35 ± 0.04 l/min, BSL = 0.44 ± 0.04 l/min; P = 0.12). Forced vital capacity (controlling for height) and the residuals of VO2peak (controlling for weight) had a significant association in the BHA group only ( r = 0.155; P = 0.031). In sum, results indicate that developmental exposure to altitude constitutes an important factor to determine superior exercise performance. Am J Phys Anthropol 156:363-373, 2015. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Focuses on a study which measured the peak oxygen consumption of adult males in Bolivia, using a migrant study design to partition developmental from ancestral effects of high-altitude exposure. Subjects and study design; Results; Discussion and conclusion.