The effect of hypoxemia and exercise on acute mountain sickness symptoms

2013 ◽  
Vol 114 (2) ◽  
pp. 180-185 ◽  
Author(s):  
Thomas Rupp ◽  
Marc Jubeau ◽  
Guillaume Y. Millet ◽  
Stéphane Perrey ◽  
François Esteve ◽  
...  
Keyword(s):  
Power Output ◽  
Physiological Stress ◽  
Arterial Oxygen Saturation ◽  
Acute Mountain Sickness ◽  
Arterial Oxygen ◽  
Hypoxic Exposure ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Mountain Sickness ◽  
Hypoxic Exercise

Performing exercise during the first hours of hypoxic exposure is thought to exacerbate acute mountain sickness (AMS), but whether this is due to increased hypoxemia or other mechanisms associated with exercise remains unclear. In 12 healthy men, AMS symptoms were assessed during three 11-h experimental sessions: 1) in Hypoxia-exercise, inspiratory O2 fraction (FiO2) was 0.12, and subjects performed 4-h cycling at 45% FiO2-specific maximal power output from the 4th to the 8th hour; 2) in Hypoxia-rest, FiO2 was continuously adjusted to match the same arterial oxygen saturation as in Hypoxia-exercise, and subjects remained at rest; and 3) in Normoxia-exercise, FiO2 was 0.21, and subjects cycled as in Hypoxia-exercise at 45% FiO2-specific maximal power output. AMS scores did not differ significantly between Hypoxia-exercise and Hypoxia-rest, while they were significantly lower in Normoxia-exercise (Lake Louise score: 5.5 ± 2.1, 4.4 ± 2.4, and 2.3 ± 1.5, and cerebral Environmental Symptom Questionnaire: 1.2 ± 0.7, 1.0 ± 1.0, and 0.3 ± 0.4, in Hypoxia-exercise, Hypoxia-rest, and Normoxia-exercise, respectively; P < 0.01). Headache scored by visual analog scale was higher in Hypoxia-exercise and Hypoxia-rest compared with Normoxia-exercise (36 ± 22, 35 ± 25, and 5 ± 6, P < 0.001), while the perception of fatigue was higher in Hypoxia-exercise compared with Hypoxia-rest (60 ± 24, 32 ± 22, and 46 ± 23, in Hypoxia-exercise, Hypoxia-rest, and Normoxia-exercise, respectively; P < 0.01). Despite significant physiological stress during hypoxic exercise and some AMS symptoms induced by normoxic cycling at similar relative workload, exercise does not significantly worsen AMS severity during the first hours of hypoxic exposure at a given arterial oxygen desaturation. Hypoxemia per se appears, therefore, to be the main mechanism underlying AMS, whether or not exercise is performed.

Intermittent hypoxia increases ventilation and SaO2 during hypoxic exercise and hypoxic chemosensitivity

2001 ◽  
Vol 90 (4) ◽  
pp. 1431-1440 ◽  
Author(s):  
Keisho Katayama ◽  
Yasutake Sato ◽  
Yoshifumi Morotome ◽  
Norihiro Shima ◽  
Koji Ishida ◽  
...  
Keyword(s):  
Intermittent Hypoxia ◽  
Minute Ventilation ◽  
Acute Hypoxia ◽  
Arterial Oxygen Saturation ◽  
Submaximal Exercise ◽  
Arterial Oxygen ◽  
Hypoxic Exposure ◽  
Hypoxic Ventilatory Response ◽  
Ventilatory Equivalent ◽  
Hypoxic Exercise

The purpose of this study was 1) to test the hypothesis that ventilation and arterial oxygen saturation (SaO2 ) during acute hypoxia may increase during intermittent hypoxia and remain elevated for a week without hypoxic exposure and 2) to clarify whether the changes in ventilation and SaO2 during hypoxic exercise are correlated with the change in hypoxic chemosensitivity. Six subjects were exposed to a simulated altitude of 4,500 m altitude for 7 days (1 h/day). Oxygen uptake (V˙o 2), expired minute ventilation (V˙e), and SaO2 were measured during maximal and submaximal exercise at 432 Torr before (Pre), after intermittent hypoxia (Post), and again after a week at sea level (De). Hypoxic ventilatory response (HVR) was also determined. At both Post and De, significant increases from Pre were found in HVR at rest and in ventilatory equivalent for O2(V˙e/V˙o 2) and SaO2 during submaximal exercise. There were significant correlations among the changes in HVR at rest and inV˙e/V˙o 2 and SaO2 during hypoxic exercise during intermittent hypoxia. We conclude that 1 wk of daily exposure to 1 h of hypoxia significantly improved oxygenation in exercise during subsequent acute hypoxic exposures up to 1 wk after the conditioning, presumably caused by the enhanced hypoxic ventilatory chemosensitivity.

Angiotensin Converting Enzyme Response to Hypoxia in Man: Its Role in Altitude Acclimatization

1984 ◽  
Vol 67 (4) ◽  
pp. 453-456 ◽  
Author(s):  
J. S. Milledge ◽  
D. M. Catley
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Oxygen Saturation ◽  
Human Subjects ◽  
Arterial Oxygen Saturation ◽  
Venous Blood ◽  
Acute Mountain Sickness ◽  
Arterial Oxygen ◽  
Converting Enzyme ◽  
Ace Activity ◽  
Mountain Sickness

1. The response of serum angiotensin converting enzyme (ACE) activity to three grades of hypoxia was studied in two groups of human subjects. Hypoxic gas mixtures having oxygen concentrations of 14, 12.6 and 10.4% were breathed successively for a period of 10 min at each concentration. Venous blood was sampled at the end of each of the three periods and arterial oxygen saturation was recorded throughout the experiment. 2. The subjects were selected as being ‘good’ or ‘poor’ acclimatizers according to their history of acute mountain sickness. There were five subjects in each group. 3. Hypoxia resulted in a reduction in ACE activity in both groups, the reduction being linear with respect to arterial oxygen saturation. 4. The reduction in ACE activity was greater in the good acclimatizer group as shown by a significantly greater slope of the response line of ACE activity to arterial oxygen saturation. 5. The significance of this finding in relation to the mechanism underlying acute mountain sickness is discussed.

Exercise intensity typical of mountain climbing does not exacerbate acute mountain sickness in normobaric hypoxia

2012 ◽  
Vol 113 (7) ◽  
pp. 1068-1074 ◽  
Author(s):  
Kai Schommer ◽  
Moritz Hammer ◽  
Lorenz Hotz ◽  
Elmar Menold ◽  
Peter Bärtsch ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Saturation ◽  
Maximal Oxygen Uptake ◽  
Arterial Oxygen Saturation ◽  
Acute Mountain Sickness ◽  
Normobaric Hypoxia ◽  
Arterial Oxygen ◽  
Moderate Exercise ◽  
Significant Difference ◽  
Mountain Sickness

Physical exertion is thought to exacerbate acute mountain sickness (AMS). In this prospective, randomized, crossover trial, we investigated whether moderate exercise worsens AMS in normobaric hypoxia (12% oxygen, equivalent to 4,500 m). Sixteen subjects were exposed to altitude twice: once with exercise [3 × 45 min within the first 4 h on a bicycle ergometer at 50% of their altitude-specific maximal workload (maximal oxygen uptake)], and once without. AMS was evaluated by the Lake Louise score and the AMS-C score of the Environmental Symptom Questionnaire. There was no significant difference in AMS between the exposures with and without exercise, neither after 5, 8, nor 18 h (incidence: 64 and 43%; LLS: 6.5 ± 0.7 and 5.1 ± 0.8; AMS-C score: 1.2 ± 0.3 and 1.1 ± 0.3 for exercise vs. rest at 18 h; all P > 0.05). Exercise decreased capillary Po2 (from 36 ± 1 Torr at rest to 31 ± 1 Torr), capillary arterial oxygen saturation (from 72% at rest to 67 ± 2%), and cerebral oxygen saturation (from 49 ± 2% at rest to 42 ± 1%, as assessed by near-infrared spectroscopy; P < 0.05), and increased ventilation (capillary Pco2 27 ± 1 Torr; P < 0.05). After exercise, the increase in ventilation persisted for several hours and was associated with similar levels of capillary and cerebral oxygenation at the exercise and rest day. We conclude that moderate exercise at ∼50% maximal oxygen uptake does not increase AMS in normobaric hypoxia. These data do not exclude that considerably higher exercise intensities exacerbate AMS.

Prediction of Acute Mountain Sickness by Monitoring Arterial Oxygen Saturation During Ascent

2010 ◽  
Vol 11 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Heikki M. Karinen ◽  
Juha E. Peltonen ◽  
Mika Kähönen ◽  
Heikki O. Tikkanen
Keyword(s):  
Oxygen Saturation ◽  
Arterial Oxygen Saturation ◽  
Acute Mountain Sickness ◽  
Arterial Oxygen ◽  
Mountain Sickness

scholarly journals Hypoxic Exercise Exacerbates Hypoxemia and Acute Mountain Sickness in Obesity: A Case Analysis

2021 ◽  
Vol 18 (17) ◽  
pp. 9078
Author(s):  
Jing Xu ◽  
Jinshu Zeng ◽  
Yelei Yan ◽  
Fei Xu
Keyword(s):  
Acute Hypoxia ◽  
Acute Mountain Sickness ◽  
Case Analysis ◽  
Activity Level ◽  
Hypoxic Exposure ◽  
Public Health Issue ◽  
Severe Hypoxemia ◽  
Peripheral Oxygen Saturation ◽  
Mountain Sickness ◽  
Hypoxic Exercise

Acute mountain sickness (AMS) is a common syndrome characterized by headache, dizziness, loss of appetite, weakness, and nausea. As a major public health issue, obesity has increased in high altitude urban residents and intermittent commuters to high altitudes. The present study investigated acute hypoxic exposure and hypoxic exercise on hypoxemia severity and AMS symptoms in a physically active obese man. In this case analysis, peripheral oxygen saturation (SpO2) was used to evaluate hypoxemia, heart rate (HR) and blood pressure (BP) were used to reflect the function of autonomic nervous system (ANS), and Lake Louise scoring (LLS) was used to assess AMS. The results showed that acute hypoxic exposure led to severe hypoxemia (SpO2 = 72%) and tachycardia (HRrest = 97 bpm), and acute hypoxic exercise exacerbated severe hypoxemia (SpO2 = 59%) and ANS dysfunction (HRpeak = 167 bpm, SBP/DBP = 210/97 mmHg). At the end of the 6-h acute hypoxic exposure, the case developed severe AMS (LLS = 10) symptoms of headache, gastrointestinal distress, cyanosis, vomiting, poor appetite, and fatigue. The findings of the case study suggest that high physical activity level appears did not show a reliable protective effect against severe hypoxemia, ANS dysfunction, and severe AMS symptoms in acute hypoxia exposure and hypoxia exercise.

Association of Arterial Oxygen Saturation and Acute Mountain Sickness Susceptibility: A Meta-analysis

2014 ◽  
Vol 70 (2) ◽  
pp. 1427-1432 ◽  
Author(s):  
Guoning Guo ◽  
Guoyan Zhu ◽  
Wei Sun ◽  
Changlin Yin ◽  
Xiaobao Ren ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Meta Analysis ◽  
Arterial Oxygen Saturation ◽  
Acute Mountain Sickness ◽  
Arterial Oxygen ◽  
Mountain Sickness

scholarly journals Exercise exacerbates acute mountain sickness at simulated high altitude

2000 ◽  
Vol 88 (2) ◽  
pp. 581-585 ◽  
Author(s):  
R. C. Roach ◽  
D. Maes ◽  
D. Sandoval ◽  
R. A. Robergs ◽  
M. Icenogle ◽  
...  
Keyword(s):  
High Altitude ◽  
Minute Ventilation ◽  
Arterial Oxygen Saturation ◽  
Acute Mountain Sickness ◽  
Urine Volume ◽  
Barometric Pressure ◽  
Arterial Oxygen ◽  
Simulated High Altitude ◽  
Mountain Sickness ◽  
Exercise Induced

.—We hypothesized that exercise would cause greater severity and incidence of acute mountain sickness (AMS) in the early hours of exposure to altitude. After passive ascent to simulated high altitude in a decompression chamber [barometric pressure = 429 Torr, ∼4,800 m (J. B. West, J. Appl. Physiol. 81: 1850–1854, 1996)], seven men exercised (Ex) at 50% of their altitude-specific maximal workload four times for 30 min in the first 6 h of a 10-h exposure. On another day they completed the same protocol but were sedentary (Sed). Measurements included an AMS symptom score, resting minute ventilation (V˙e), pulmonary function, arterial oxygen saturation ([Formula: see text]), fluid input, and urine volume. Symptoms of AMS were worse in Ex than Sed, with peak AMS scores of 4.4 ± 1.0 and 1.3 ± 0.4 in Ex and Sed, respectively ( P < 0.01); but restingV˙e and[Formula: see text] were not different between trials. However, [Formula: see text] during the exercise bouts in Ex was at 76.3 ± 1.7%, lower than during either Sed or at rest in Ex (81.4 ± 1.8 and 82.2 ± 2.6%, respectively, P< 0.01). Fluid intake-urine volume shifted to slightly positive values in Ex at 3–6 h ( P = 0.06). The mechanism(s) responsible for the rise in severity and incidence of AMS in Ex may be sought in the observed exercise-induced exaggeration of arterial hypoxemia, in the minor fluid shift, or in a combination of these factors.

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