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Abstract
BACKGROUND The aim of the study was to provide a theoretical basis for the early diagnosis and prediction of acute altitude sickness, to provide a better entry mode for healthy people from plain areas to plateau areas, and to preliminarily clarify the possible mechanism of this approach. METHODS We measured endothelin-1 (ET-1), asymmetric dimethylarginine (ADMA), vascular endothelial growth factor (VEGF), nitric oxide (NO), and hypoxia-inducible factor 1 (HIF-1) levels in each sample and determined flow-mediated dilation (FMD) values using a portable OMRON color Doppler with a 7.0- to 12.0-MHz linear array probe. We used the Lewis Lake score to diagnose acute mountain sickness (AMS) and to stratify the disease severity. RESULTS We found no cases of AMS at any of the studied elevation gradients. We found significant differences in FMD values between individuals when at 400 m above sea level and when at 2200, 3200, and 4200 m above sea level (P < .05) but found no significant differences among those at 2200, 3200, and 4200 m. Our variance analysis showed that serum ET-1, VEGF, ADMA, NO, and HIF-1 levels in individuals at ≥3000 m and those at subplateau and plain areas (<3000 m) significantly differed (P < .05). The level of these factors also significantly differed between individuals at elevation gradients of plateau areas (3260 m vs 4270 m) (P < .05). We found no significant differences in serum ET-1, VEGF, and ADMA levels between individuals at the plateau (2260 m) and plain (400 m) areas (P > .05). NO and HIF-1 levels were significantly different in serum samples from individuals between the plateau (2260 m) and plain (400 m) areas (P < .05). However, with increasing altitude, the NO level gradually increased, whereas ET-1, ADMA, VEGF, and HIF-1 levels showed a decreasing trend. With the increase of altitude, there is no correlation between the trend of FMD and hematologic-related factors such as VEGF, NO, and HIF-1. CONCLUSION A healthy young male population ascending to a high-altitude area experiences a low incidence of AMS. Entering an acute plateau exposure environment from different altitude gradients may weaken the effect of acute highland exposure on vascular endothelial dysfunction in healthy individuals. Changes in serum ET-1, VEGF, ADMA, NO, and HIF-1 levels in healthy young men may be related to the body's self-regulation and protect healthy individuals from AMS. A short stay in a subplateau region may initiate an oxygen-free preconditioning process in healthy individuals, thereby protecting them from AMS. Noninvasive brachial artery endothelial function test instead of the detection of invasive hematologic-related factors for early diagnosis and prediction of the occurrence and severity of acute high-altitude disease is still lack of sufficient theoretical basis.
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Affiliation(s)
- Ning Fan
- Graduate School of Qinghai University
| | - Cun Liu
- Qinghai Cardiovascular Hospital
| | - Ming Ren
- The Affiliated Hospital of Qing Hai University, Xi Ning, Qing Hai, China
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Woods DR, O'Hara JP, Boos CJ, Hodkinson PD, Tsakirides C, Hill NE, Jose D, Hawkins A, Phillipson K, Hazlerigg A, Arjomandkhah N, Gallagher L, Holdsworth D, Cooke M, Green NDC, Mellor A. Markers of physiological stress during exercise under conditions of normoxia, normobaric hypoxia, hypobaric hypoxia, and genuine high altitude. Eur J Appl Physiol 2017; 117:893-900. [PMID: 28299447 PMCID: PMC5388721 DOI: 10.1007/s00421-017-3573-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/13/2017] [Indexed: 11/29/2022]
Abstract
Purpose To investigate whether there is a differential response at rest and following exercise to conditions of genuine high altitude (GHA), normobaric hypoxia (NH), hypobaric hypoxia (HH), and normobaric normoxia (NN). Method Markers of sympathoadrenal and adrenocortical function [plasma normetanephrine (PNORMET), metanephrine (PMET), cortisol], myocardial injury [highly sensitive cardiac troponin T (hscTnT)], and function [N-terminal brain natriuretic peptide (NT-proBNP)] were evaluated at rest and with exercise under NN, at 3375 m in the Alps (GHA) and at equivalent simulated altitude under NH and HH. Participants cycled for 2 h [15-min warm-up, 105 min at 55% Wmax (maximal workload)] with venous blood samples taken prior (T0), immediately following (T120) and 2-h post-exercise (T240). Results Exercise in the three hypoxic environments produced a similar pattern of response with the only difference between environments being in relation to PNORMET. Exercise in NN only induced a rise in PNORMET and PMET. Conclusion Biochemical markers that reflect sympathoadrenal, adrenocortical, and myocardial responses to physiological stress demonstrate significant differences in the response to exercise under conditions of normoxia versus hypoxia, while NH and HH appear to induce broadly similar responses to GHA and may, therefore, be reasonable surrogates.
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Affiliation(s)
- David Richard Woods
- Royal Centre for Defence Medicine, Birmingham, UK. .,Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK. .,University of Newcastle, Newcastle upon Tyne, UK. .,Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK.
| | - John Paul O'Hara
- Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - Christopher John Boos
- Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK.,Department of Cardiology, Poole Hospital NHS Foundation Trust, Poole, UK.,Department of Postgraduate Medical Education, Bournemouth University, Poole, UK
| | | | - Costas Tsakirides
- Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - Neil Edward Hill
- Royal Centre for Defence Medicine, Birmingham, UK.,Imperial College London, London, UK.,Charing Cross Hospital, London, UK
| | - Darren Jose
- Pathology, Poole Hospital NHS Foundation Trust, Poole, UK
| | - Amanda Hawkins
- Pathology, Poole Hospital NHS Foundation Trust, Poole, UK
| | - Kelly Phillipson
- Department of Biochemistry, Freeman Hospital, Freeman Road, Newcastle upon Tyne, UK
| | | | | | - Liam Gallagher
- Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | | | - Mark Cooke
- Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | | | - Adrian Mellor
- Royal Centre for Defence Medicine, Birmingham, UK.,Research Institute, for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK.,James Cook University Hospital, Middlesbrough, TS4 3BW, UK
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