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Accession Number ADA575842
Title Predictive Models of Acute Mountain Sickness after Rapid Ascent to Various Altitudes.
Publication Date 2013
Media Count 10p
Personal Author B. A. Beidleman C. H. Schmid C. S. Fulco H. Tighiouart S. R. Muza
Abstract Purpose: Despite decades of research, no predictive models of acute mountain sickness (AMS) exist, which identify the time course of AMS severity and prevalence following rapid ascent to various altitudes. Methods: Using general linear and logistic mixed models and a comprehensive database, we analyzed 1292 AMS cerebral factor scores in 308 unacclimatized men and women who spent between 4 and 48 h at altitudes ranging from 1659 to 4501 m under experimentally controlled conditions (low and high activity). Covariates included in the analysis were altitude, time at altitude, activity level, age, body mass index, race, sex, and smoking status. Results: AMS severity increased (P G 0.05) nearly twofold (i.e., 179%) for every 1000-m increase in altitude at 20 h of exposure, peaked between 18 and 22 h of exposure, and returned to initial levels by 48 h of exposure regardless of sex or activity level. Peak AMS severity scores were 38% higher (P G 0.05) in men compared with women at 20 h of exposure. High active men and women (950% of maximal oxygen uptake for 945 min at altitude) demonstrated a 72% increase (P G 0.05) in the odds (odds ratio, 1.72; confidence interval, 1.03-3.08) of AMS compared with low active men and women. There was also a tendency (P = 0.10) for men to demonstrate greater odds of AMS (odds ratio, 1.65; confidence interval, 0.84-3.25) compared with women. Age, body mass index, race, and smoking status were not significantly associated with AMS. Conclusions: These models provide the first quantitative estimates of AMS risk over a wide range of altitudes and time points and suggest that in addition to altitude and time at altitude, high activity increases the risk of developing AMS. In addition, men demonstrated increased severity but not prevalence of AMS.
Keywords Altitude
Altitude sickness
Ams(Acute mountain sickness)
Ascent trajectories
Hypobaric hypoxia
Mixed models
Statistical analysis
Unacclimatized lowlanders

Source Agency Non Paid ADAS
NTIS Subject Category 57E - Clinical Medicine
57W - Stress Physiology
72F - Statistical Analysis
Corporate Author Army Research Inst. of Environmental Medicine, Natick, MA. Thermal and Mountain Medicine Div.
Document Type Journal article
Title Note Journal article.
NTIS Issue Number 1319
Contract Number N/A

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