Body water metabolism in high altitude natives during and after a stay at sea level

1981 ◽  
Vol 25 (1) ◽  
pp. 47-52 ◽  
Author(s):  
S. C. Jain ◽  
Jaya Bardhan ◽  
Y. V. Swamy ◽  
A. Grover ◽  
H. S. Nayar
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Body Water ◽  
Water Metabolism ◽  
High Altitude Natives

Fructose metabolism in sea-level and high-altitude natives

1969 ◽  
Vol 216 (6) ◽  
pp. 1542-1547
Author(s):  
B Reynafarje ◽  
L Oyola ◽  
R Cheesman ◽  
E Marticorena ◽  
S Jimenez
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Fructose Metabolism ◽  
High Altitude Natives

Cardiovascular autonomic modulation and activity of carotid baroreceptors at altitude

1998 ◽  
Vol 95 (5) ◽  
pp. 565-573 ◽  
Author(s):  
Luciano BERNARDI ◽  
Claudio PASSINO ◽  
Giammario SPADACINI ◽  
Alessandro CALCIATI ◽  
Robert ROBERGS ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Systolic Blood Pressure ◽  
High Altitude ◽  
Sea Level ◽  
Skin Blood Flow ◽  
Low Frequency ◽  
Sympathetic Activation ◽  
High Altitude Natives

1.To assess the effects of acute exposure to high altitude on baroreceptor function in man we evaluated the effects of baroreceptor activation on R–R interval and blood pressure control at high altitude. We measured the low-frequency (LF) and high-frequency (HF) components in R–R, non-invasive blood pressure and skin blood flow, and the effect of baroreceptor modulation by 0.1-Hz sinusoidal neck suction. Ten healthy sea-level natives and three high-altitude native, long-term sea-level residents were evaluated at sea level, upon arrival at 4970 ;m and 1 week later. 2.Compared with sea level, acute high altitude decreased R–R and increased blood pressure in all subjects [sea-level natives: R–R from 1002±45 to 775±57 ;ms, systolic blood pressure from 130±3 to 150±8 ;mmHg; high-altitude natives: R–R from 809±116 to 749±47 ;ms, systolic blood pressure from 110±12 to 125±11 ;mmHg (P< 0.05 for all)]. One week later systolic blood pressure was similar to values at sea level in all subjects, whereas R–R remained elevated in sea-level natives. The low-frequency power in R–R and systolic blood pressure increased in sea-level natives [R–R-LF from 47±8 to 65±10% (P< 0.05), systolic blood pressure-LF from 1.7±0.3 to 2.6±0.4 ln-mmHg2 (P< 0.05)], but not in high-altitude natives (R–R-LF from 32±13 to 38±19%, systolic blood pressure-LF from 1.9±0.5 to 1.7±0.8 ln-mmHg2). The R–R-HF decreased in sea-level natives but not in high-altitude natives, and no changes occurred in systolic blood pressure-HF. These changes remained evident 1 week later. Skin blood flow variability and its spectral components decreased markedly at high altitude in sea-level natives but showed no changes in high-altitude natives. Neck suction significantly increased the R–R- and systolic blood pressure-LF in all subjects at both sea level and high altitude. 3.High altitude induces sympathetic activation in sea-level natives which is partially counteracted by active baroreflex. Despite long-term acclimatization at sea level, high-altitude natives also maintain active baroreflex at high altitude but with lower sympathetic activation, indicating a persisting high-altitude adaptation which may be genetic or due to baroreflex activity not completely lost by at least 1 year's sea-level residence.

Training in hypoxia vs. training in normoxia in high-altitude natives

1995 ◽  
Vol 78 (6) ◽  
pp. 2286-2293 ◽  
Author(s):  
R. Favier ◽  
H. Spielvogel ◽  
D. Desplanches ◽  
G. Ferretti ◽  
B. Kayser ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Maximal Exercise ◽  
Work Intensity ◽  
Maximal Aerobic Capacity ◽  
Trained Subjects ◽  
Arterial Ph ◽  
High Altitude Natives ◽  
Blood Lactate Accumulation ◽  
O2 Delivery

To determine the interactions between endurance training and hypoxia on maximal exercise performance, we performed a study on sedentary high-altitude natives who were trained in normoxia at the same relative (n = 10) or at the same absolute (n = 10) intensity of work as hypoxia-trained subjects (n = 10). The training-induced improvement of maximal oxygen uptake (VO2max) in hypoxia-trained subjects was similar to that obtained in normoxia-trained sea-level natives submitted to the same training protocol (H. Hoppeler, H. Howald, K. Conley, S. L. Lindstedt, H. Claassen, P. Vock, and E. W. Weibel. J. Appl. Physiol. 59: 320–327, 1985). Training at the same absolute work intensity in the presence of increased oxygen delivery failed to provide a further increase in VO2max. VO2max was not improved to a greater extent by simultaneously increasing absolute work intensity and O2 delivery during the training sessions. In addition, training in normoxia is accompanied by an increased blood lactate accumulation during maximal exercise, leading to greater drops in arterial pH, bicarbonate concentration, and base excess. We conclude that, in high-altitude natives, 1) training at altitude does not provide any advantage over training at sea level for maximal aerobic capacity, whether assessed in chronic hypoxia or in acute normoxia; 2) VO2max improvement with training cannot be further enhanced by increasing O2 availability alone or in combination with an increased work intensity during the exercising sessions; and 3) training in normoxia in these subjects results in a reduced buffer capacity.

Selected Contribution: Acute and sustained ventilatory responses to hypoxia in high-altitude natives living at sea level

2003 ◽  
Vol 94 (3) ◽  
pp. 1255-1262 ◽  
Author(s):  
Alfredo Gamboa ◽  
Fabiola León-Velarde ◽  
Maria Rivera-Ch ◽  
Jose-Antonio Palacios ◽  
Timothy R. Pragnell ◽  
...  
Keyword(s):  
Confidence Interval ◽  
High Altitude ◽  
Sea Level ◽  
Hypoxic Exposure ◽  
Ventilatory Responses ◽  
High Altitude Natives ◽  
Ventilatory Depression ◽  
End Tidal ◽  
Sustained Hypoxia

High-altitude (HA) natives have blunted ventilatory responses to hypoxia (HVR), but studies differ as to whether this blunting is lost when HA natives migrate to live at sea level (SL), possibly because HVR has been assessed with different durations of hypoxic exposure (acute vs. sustained). To investigate this, 50 HA natives (>3,500 m, for >20 yr) now resident at SL were compared with 50 SL natives as controls. Isocapnic HVR was assessed by using two protocols: protocol 1, progressive stepwise induction of hypoxia over 5–6 min; and protocol 2, sustained (20-min) hypoxia (end-tidal Po 2 = 50 Torr). Acute HVR was assessed from both protocols, and sustained HVR from protocol 2. For HA natives, acute HVR was 79% [95% confidence interval (CI): 52–106%, P = not significant] of SL controls for protocol 1 and 74% (95% CI: 52–96%, P < 0.05) for protocol 2. By contrast, sustained HVR after 20-min hypoxia was only 30% (95% CI: −7–67%, P < 0.001) of SL control values. The persistent blunting of HVR of HA natives resident at SL is substantially less to acute than to sustained hypoxia, when hypoxic ventilatory depression can develop.

Alveolar P CO 2 and P O 2 of high-altitude natives living at sea level

1996 ◽  
Vol 81 (4) ◽  
pp. 1605-1609 ◽  
Author(s):  
Fabiola León-Velarde ◽  
Manuel Vargas ◽  
Carlos Monge-C. ◽  
Robert W. Torrance ◽  
Peter A. Robbins
Keyword(s):  
Confidence Interval ◽  
High Altitude ◽  
Sea Level ◽  
Average Difference ◽  
Control Subjects ◽  
High Altitude Natives ◽  
End Tidal

León-Velarde, Fabiola, Manuel Vargas, Carlos Monge-C., Robert W. Torrance, and Peter A. Robbins. Alveolar[Formula: see text] and[Formula: see text] of high-altitude natives living at sea level. J. Appl. Physiol. 81(4): 1605–1609, 1996.—This study was designed to determine whether subjects born at high altitude (HA; 2,000 m or above) who subsequently move to near sea level (SL) develop end-tidal [Formula: see text]([Formula: see text]) and[Formula: see text]([Formula: see text]) values that equal those of SL natives living near SL. A total of 108 male HA natives living near SL were identified by survey of a district in Lima, Peru, and a further 108 male SL natives from the same district were identified as control subjects. Of these subjects, satisfactory data for inclusion in the study were obtained from 93 HA and 82 SL subjects. Mean [Formula: see text] and[Formula: see text] values were 37.7 ± 2.5 (SD) and 104.7 ± 3.2 Torr, respectively, in HA subjects and 37.7 ± 2.2 and 104.8 ± 3.0 Torr, respectively, in SL subjects. The average difference between SL natives and HA natives for[Formula: see text] was 0.07 Torr (−0.64 to 0.78; 95% confidence interval) and for[Formula: see text] was 0.05 Torr (−0.89 to 0.99, 95% confidence interval). The average age and weight of the SL and HA subjects did not differ, but the HA subjects were shorter and tended to have larger vital capacities, consistent with their origin at HA. We conclude that the[Formula: see text] and[Formula: see text] near SL of SL natives and HA natives do not differ.

Tolerance to acute anoxia in high altitude natives

1959 ◽  
Vol 14 (3) ◽  
pp. 357-362 ◽  
Author(s):  
Tulio Velásquez
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Technical Assistance ◽  
Acute Hypoxia ◽  
Low Pressure ◽  
Pressure Chamber ◽  
Relative Influence ◽  
Acute Anoxia ◽  
High Altitude Natives

Native residents living at an altitude of 14,900 feet were suddenly exposed to simulated higher altitudes, ranging from 30 to 40,000 feet, in a low pressure chamber. The ‘time of consciousness’ and the ceiling breathing air were determined. In addition, observations were made on the respiratory characteristics at these altitudes. Comparing the results with those given by previous investigators using sea level residents, they indicate that a man born and living at an altitude of 14,900 feet has a definitely greater tolerance to acute hypoxia than a man born and residing at sea level. The relative influence of hypoxia and hypocapnia on the symptoms which developed during this test is discussed. Note: (With the Technical Assistance of Edgard Florentini and Melquiades Huayna-Vera) Submitted on June 2, 1958

scholarly journals The sleep of elite athletes at sea level and high altitude: a comparison of sea-level natives and high-altitude natives (ISA3600)

2013 ◽  
Vol 47 (Suppl 1) ◽  
pp. i114-i120 ◽  
Author(s):  
Gregory D Roach ◽  
Walter F Schmidt ◽  
Robert J Aughey ◽  
Pitre C Bourdon ◽  
Rudy Soria ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Elite Athletes ◽  
High Altitude Natives

Effects of chronic hypoxia and exercise on plasma erythropoietin in high-altitude residents

1993 ◽  
Vol 74 (4) ◽  
pp. 1874-1878 ◽  
Author(s):  
W. Schmidt ◽  
H. Spielvogel ◽  
K. U. Eckardt ◽  
A. Quintela ◽  
R. Penaloza
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Cycle Ergometer ◽  
Control Group ◽  
Ergometer Exercise ◽  
High Altitude Natives ◽  
The Mean ◽  
The Relationship ◽  
Arterial Po2 ◽  
Level Group

The present study was performed to evaluate the effects of chronic inspiratory hypoxia and its combination with physical exercise on plasma erythropoietin concentration ([EPO]). Eight natives from the Bolivian Plateau were investigated at 3,600 m above sea level at rest as well as during and up to 48 h after exhaustive exercise (EE) and 60 min of submaximal (60%) cycle ergometer exercise (SE). Ten sea-level subjects were used as a control group for resting values. The mean resting plasma [EPO] of the high-altitude group (19.5 +/- 0.7 mU/ml) did not differ from that of the sea-level group (18.1 +/- 0.4 mU/ml) but was higher than would be expected from the relationship between [EPO] and hematocrit at sea level. Five hours after both types of exercise, [EPO] decreased by 2.1 +/- 0.8 (EE, P < 0.01) and 1.6 +/- 0.8 mU/ml (SE, P < 0.05); 48 h after SE, [EPO] increased by 2.6 +/- 0.9 mU/ml (P < 0.05). It is concluded that 1) high-altitude natives need relatively high [EPO] to maintain their high hematocrit and 2) exercise at low basal arterial PO2 does not directly increase plasma [EPO] in high-altitude residents but seems to exert suppressive effects.

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