Intermittent altitude exposures reduce acute mountain sickness at 4300 m
| Autor: | Gary S. Skrinar, Dean A. Stulz, Allen Cymerman, Michael N. Sawka, Beth A. Beidleman, Dan T. Ditzler, Stephen R. Muza, S. F. Lewis, Charles S. Fulco, Janet E. Staab |
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| Rok vydání: | 2004 |
| Předmět: |
Adult
Male medicine.medical_specialty Time Factors Acclimatization Urination Urine Altitude Sickness Altitude Animal science medicine Humans Exercise Altitude sickness Analysis of Variance business.industry Incidence (epidemiology) VO2 max General Medicine Hypoxia (medical) medicine.disease Bicycling Respiratory Function Tests Surgery Acute Disease Breathing Female medicine.symptom business |
| Zdroj: | Clinical Science. 106:321-328 |
| ISSN: | 1470-8736 0143-5221 |
| Popis: | Acute mountain sickness (AMS) commonly occurs at altitudes exceeding 2000-2500 m and usually resolves after acclimatization induced by a few days of chronic residence at the same altitude. Increased ventilation and diuresis may contribute to the reduction in AMS with altitude acclimatization. The aim of the present study was to examine the effects of intermittent altitude exposures (IAE), in combination with rest and exercise training, on the incidence and severity of AMS, resting ventilation and 24-h urine volume at 4300 m. Six lowlanders (age, 23 +/- 2 years; body weight, 77 +/- 6 kg; values are means +/- S.E.M.) completed an Environmental Symptoms Questionnaire (ESQ) and Lake Louise AMS Scoring System (LLS), a resting end-tidal partial pressure of CO2 ( PETCO2) test and a 24-h urine volume collection at sea level (SL) and during a 30 h exposure to 4300 m altitude-equivalent (barometric pressure=446 mmHg) once before (PreIAE) and once after (PostIAE) a 3-week period of IAE (4 h.day(-1), 5 days.week(-1), 4300 m). The previously validated factor score, AMS cerebral score, was calculated from the ESQ and the self-report score was calculated from the LLS at 24 h of altitude exposure to assess the incidence and severity of AMS. During each IAE, three subjects cycled for 45-60 min.day(-1) at 60-70% of maximal O2 uptake (VO2 max) and three subjects rested. Cycle training during each IAE did not affect any of the measured variables, so data from all six subjects were combined. The results showed that the incidence of AMS (%), determined from both the ESQ and LLS, increased (P |
| Databáze: | OpenAIRE |
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