T P Lyons1, S R Muza, P B Rock, A Cymerman. 1. Altitude Physiology and Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA.
Abstract
BACKGROUND: Acclimatization to high altitude appears to prevent acute mountain sickness (AMS), as evidenced by a decline in AMS symptoms as acclimatization progresses. HYPOTHESIS: We hypothesized that partial retention of acclimatization would attenuate the incidence and/or severity of AMS upon reinduction to altitude. METHODS: To test this hypothesis 6 male lowlanders returned to sea level after the acclimatizing of the 16 d at 4300 m (HA). After 8 d at sea level (PA), they were reexposed to 4300 m in a hypobaric chamber for 30 h (RA). AMS symptom severity was determined by the AMS-cerebral (AMS-C) scores calculated from the daily administration of the Environmental Symptoms Questionnaire during HA and RA. RESULTS: The mean AMS-C scores were reduced from 0.6 on HA day 1 (HA1) to 0.1 during RA (p < 0.05). Four subjects were "sick" (AMS-C > 0.7) during HA1, while only one was "sick" during RA. The % oxyhemoglobin, hemoglobin concentration and hematocrit were higher during RA compared to HA1. CONCLUSIONS: These results suggest that the retention of acclimatization after 8 d at low altitude is sufficient to attenuate AMS upon reinduction to high altitude.
BACKGROUND: Acclimatization to high altitude appears to prevent acute mountain sickness (AMS), as evidenced by a decline in AMS symptoms as acclimatization progresses. HYPOTHESIS: We hypothesized that partial retention of acclimatization would attenuate the incidence and/or severity of AMS upon reinduction to altitude. METHODS: To test this hypothesis 6 male lowlanders returned to sea level after the acclimatizing of the 16 d at 4300 m (HA). After 8 d at sea level (PA), they were reexposed to 4300 m in a hypobaric chamber for 30 h (RA). AMS symptom severity was determined by the AMS-cerebral (AMS-C) scores calculated from the daily administration of the Environmental Symptoms Questionnaire during HA and RA. RESULTS: The mean AMS-C scores were reduced from 0.6 on HA day 1 (HA1) to 0.1 during RA (p < 0.05). Four subjects were "sick" (AMS-C > 0.7) during HA1, while only one was "sick" during RA. The % oxyhemoglobin, hemoglobin concentration and hematocrit were higher during RA compared to HA1. CONCLUSIONS: These results suggest that the retention of acclimatization after 8 d at low altitude is sufficient to attenuate AMS upon reinduction to high altitude.
Authors: G Tsianos; L Woolrich-Burt; T Aitchison; A Peacock; M Watt; H Montgomery; I Watt; S Grant Journal: Eur J Appl Physiol Date: 2005-10-19 Impact factor: 3.078
Authors: Jesús Álvarez-Herms; Sonia Julià-Sánchez; Francisco Corbi; Adrian Odriozola-Martínez; Martin Burtscher Journal: Front Physiol Date: 2019-01-15 Impact factor: 4.566
Authors: Andrew W Subudhi; Nicolas Bourdillon; Jenna Bucher; Christopher Davis; Jonathan E Elliott; Morgan Eutermoster; Oghenero Evero; Jui-Lin Fan; Sonja Jameson-Van Houten; Colleen G Julian; Jonathan Kark; Sherri Kark; Bengt Kayser; Julia P Kern; See Eun Kim; Corinna Lathan; Steven S Laurie; Andrew T Lovering; Ryan Paterson; David M Polaner; Benjamin J Ryan; James L Spira; Jack W Tsao; Nadine B Wachsmuth; Robert C Roach Journal: PLoS One Date: 2014-03-21 Impact factor: 3.240