Oxidative Stress in Hypobaric Hypoxia

Study Overview
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Brief Summary
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The trial investigates changes in metabolism during high altitude expedition up to 6865m. A mass-spectrometry based platform is used to detect different oxidative stress related metabolites. Symptoms of acute mountain sickness are evaluated and correlated with laboratory parameters.

Detailed Description
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Background Altitude related illness, which include acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE), is common in subjects exposed to high altitude during professional or leisure time activities. There are independent risk factors such as: individual susceptibility and rate of ascent. HAPE is a potentially life-threatening complication of high altitude stay, mostly occuring within the first 2-5 days of exposure. Although there is a controversial discussion, excessive hypoxic pulmonary vasoconstriction is thought to be the main trigger for developing HAPE. Beside the controversial discussion if hypobaric hypoxia leads to oxidative stress it is not known whether oxidative stress contributes to AMS or HAPE. Objective The investigators hypothesize that reactive oxygen species are generated during high altitude stay and contribute to the development of acute mountain sickness. Furthermore they would like to describe other changes in metabolic pathways possibly contributing to vessel tone dysregulation. Methods 36 healthy volunteers will examined during an high altitude medical research expedition to Mount Muztagh ata (7549m) in Western China. Acute mountain sickness scores and clinical parameters will be assessed. Metabolomics analysis of more than 390 parameters, using a mass spectrometry-based targeted metabolomic platform, is used to detect systemic oxidative stress and functional impairment of enzymes that require oxidation-sensitive co-factors. Furthermore routine laboratory test will be done, for example CRP, creatinine and interleukines

Official Title
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Oxidative Stress in Hypobaric Hypoxia and Influence on Vessel-tone Modifying Mediators

Conditions
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Hypobaric Hypoxia, Metabolomics, Oxidative Stress, Acute Mountain Sickness

Intervention / Treatment
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* Other: Hypoxic exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy physical fit mountaineering experience 18-70 years Exclusion Criteria any type of disease regular intake of medicaments history of high altitude pulmonary edema severe acute mountain sickness below an altitude of 3500m any history of high altitude cerebral edema

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Hypoxic exposure|Hypoxic exposure|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of volunteers with acute mountain sickness |  | during ascent, expected to be approximately 19-23 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in oxygen saturation in blood |  | during ascent, expected to be approximately 19-23 days | 
| Changes from baseline in oxidative stress |  | during ascent, expected to be approximately 19-23 days | 
| Changes from baseline in different metabolic pathways |  | during ascent, expected to be approximately 19-23 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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high altitude, hypobaric hypoxia, metabolomics, oxidative stress, acute mountain sickness