Send to

Choose Destination
Am J Respir Crit Care Med. 2012 Jan 15;185(2):192-8. doi: 10.1164/rccm.201108-1396OC. Epub 2011 Oct 27.

Physiological risk factors for severe high-altitude illness: a prospective cohort study.

Author information

Université Paris, Association pour la Recherche en Physiologie de l’Environnement, Unité de Formation et de Recherche Santé Médecine Biologie Humaine, Bobigny, France.



An increasing number of persons, exposed to high altitude for leisure, sport, or work, may suffer from severe high-altitude illness.


To assess, in a large cohort of subjects, the association between physiological parameters and the risk of altitude illness and their discrimination ability in a risk prediction model.


A total of 1,326 persons went through a hypoxic exercise test before a sojourn above 4,000 m. They were then monitored up at high altitude and classified as suffering from severe high-altitude illness (SHAI) or not. Analysis was stratified according to acetazolamide use.


Severe acute mountain sickness occurred in 314 (23.7%), high-altitude pulmonary edema in 22 (1.7%), and high-altitude cerebral edema in 13 (0.98%) patients. Among nonacetazolamide users (n = 917), main factors independently associated with SHAI were previous history of SHAI (adjusted odds ratios [aOR], 12.82; 95% confidence interval [CI], 6.95-23.66; P < 0.001), ascent greater than 400 m/day (aOR, 5.89; 95% CI, 3.78-9.16; P < 0.001), history of migraine (aOR, 2.28; 95% CI, 1.28-4.07; P = 0.005), ventilatory response to hypoxia at exercise less than 0.78 L/minute/kg (aOR, 6.68; 95% CI, 3.83-11.63; P < 0.001), and desaturation at exercise in hypoxia equal to or greater than 22% (aOR, 2.50; 95% CI, 1.52-4.11; P < 0.001). The last two parameters improved substantially the discrimination ability of the multivariate prediction model (C-statistic rose from 0.81 to 0.88; P < 0.001). Preventive use of acetazolamide reduced the relative risk of SHAI by 44%.


In a large population of altitude visitors, chemosensitivity parameters (high desaturation and low ventilatory response to hypoxia at exercise) were independent predictors of severe high-altitude illness. They improved the discrimination ability of a risk prediction model.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center