University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Caudwell Xtreme Everest: A prospective study of the effects of environmental hypoxia on cognitive functioning

Griva, K, Stygall, J, Wilson, MH, Martin, D, Levett, D, Mitchell, K, Mythen, M, Montgomery, HE, Grocott, MP, Aref-Adib, G, Edsell, M, Plant, T, Imray, C, Cooke, DD, Harrington, J, Khosravi, M and Newman, SP (2017) Caudwell Xtreme Everest: A prospective study of the effects of environmental hypoxia on cognitive functioning PLoS One, 12 (3). e0174277-e0174277.

Full text not available from this repository.

Abstract

Background The neuropsychological consequences of exposure to environmental hypobaric hypoxia (EHH) remain unclear. We thus investigated them in a large group of healthy volunteers who trekked to Mount Everest base camp (5,300 m). Methods A neuropsychological (NP) test battery assessing memory, language, attention, and executive function was administered to 198 participants (age 44.5±13.7 years; 60% male). These were studied at baseline (sea level), 3,500 m (Namche Bazaar), 5,300 m (Everest Base Camp) and on return to 1,300 m (Kathmandu) (attrition rate 23.7%). A comparable control group (n = 25; age 44.5±14.1 years; 60% male) for comparison with trekkers was tested at/or near sea level over an equivalent timeframe so as to account for learning effects associated with repeat testing. The Reliable Change Index (RCI) was used to calculate changes in cognition and neuropsychological function during and after exposure to EHH relative to controls. Results Overall, attention, verbal ability and executive function declined in those exposed to EHH when the performance of the control group was taken into account (RCI .05 to -.95) with decline persisting at descent. Memory and psychomotor function showed decline at highest ascent only (RCI -.08 to -.56). However, there was inter-individual variability in response: whilst NP performance declined in most, this improved in some trekkers. Cognitive decline was greater amongst older people (r = .42; p < .0001), but was otherwise not consistently associated with socio-demographic, mood, or physiological variables. Conclusions After correcting for learning effects, attention, verbal abilities and executive functioning declined with exposure to EHH. There was considerable individual variability in the response of brain function to sustained hypoxia with some participants not showing any effects of hypoxia. This might have implications for those facing sustained hypoxia as a result of any disease.

Item Type: Article
Subjects : Biosciences
Authors :
NameEmailORCID
Griva, KUNSPECIFIEDUNSPECIFIED
Stygall, JUNSPECIFIEDUNSPECIFIED
Wilson, MHUNSPECIFIEDUNSPECIFIED
Martin, DUNSPECIFIEDUNSPECIFIED
Levett, DUNSPECIFIEDUNSPECIFIED
Mitchell, KUNSPECIFIEDUNSPECIFIED
Mythen, MUNSPECIFIEDUNSPECIFIED
Montgomery, HEUNSPECIFIEDUNSPECIFIED
Grocott, MPUNSPECIFIEDUNSPECIFIED
Aref-Adib, GUNSPECIFIEDUNSPECIFIED
Edsell, MUNSPECIFIEDUNSPECIFIED
Plant, TUNSPECIFIEDUNSPECIFIED
Imray, CUNSPECIFIEDUNSPECIFIED
Cooke, DDd.cooke@surrey.ac.ukUNSPECIFIED
Harrington, JUNSPECIFIEDUNSPECIFIED
Khosravi, MUNSPECIFIEDUNSPECIFIED
Newman, SPUNSPECIFIEDUNSPECIFIED
Date : 27 March 2017
Identification Number : https://doi.org/10.1371/journal.pone.0174277
Copyright Disclaimer : Copyright: © 2017 Griva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Depositing User : Symplectic Elements
Date Deposited : 17 May 2017 10:49
Last Modified : 18 May 2017 12:44
URI: http://epubs.surrey.ac.uk/id/eprint/829316

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800