The physiological effects of hypobaric hypoxia versus normobaric hypoxia: a systematic review of crossover trials

Coppel, Jonny, Hennis, Philip, Gilbert-Kawai, Edward and Grocott, Michael P.W. (2014) The physiological effects of hypobaric hypoxia versus normobaric hypoxia: a systematic review of crossover trials Extreme Physiology & Medicine, 4, (2), pp. 1-20. (doi:10.1186/s13728-014-0021-6). (PMID:25722851).


[img] PDF - Other
Available under License Creative Commons Attribution.

Download (1MB)


Much hypoxia research has been carried out at high altitude in a hypobaric hypoxia (HH) environment. Many research teams seek to replicate high-altitude conditions at lower altitudes in either hypobaric hypoxic conditions or normobaric hypoxic (NH) laboratories. Implicit in this approach is the assumption that the only relevant condition that differs between these settings is the partial pressure of oxygen (PO2), which is commonly presumed to be the principal physiological stimulus to adaptation at high altitude. This systematic review is the first to present an overview of the current available literature regarding crossover studies relating to the different effects of HH and NH on human physiology. After applying our inclusion and exclusion criteria, 13 studies were deemed eligible for inclusion. Several studies reported a number of variables (e.g. minute ventilation and NO levels) that were different between the two conditions, lending support to the notion that true physiological difference is indeed present. However, the presence of confounding factors such as time spent in hypoxia, temperature, and humidity, and the limited statistical power due to small sample sizes, limit the conclusions that can be drawn from these findings. Standardisation of the study methods and reporting may aid interpretation of future studies and thereby improve the quality of data in this area. This is important to improve the quality of data that is used for improving the understanding of hypoxia tolerance, both at altitude and in the clinical setting.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1186/s13728-014-0021-6
Keywords: normobaric hypoxia, hypobaric hypoxia, altitude
Subjects: R Medicine > RC Internal medicine > RC1200 Sports Medicine
Organisations: NIHR Southampton Respiratory Biomedical Research Unit
ePrint ID: 384054
Date :
Date Event
18 December 2014Accepted/In Press
26 February 2015Published
Date Deposited: 08 Dec 2015 14:42
Last Modified: 17 Apr 2017 04:48
Further Information:Google Scholar

Actions (login required)

View Item View Item