Effect of Inhalation of Low Dose CO2 on Exercise Performance at High Altitude

Study Overview
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Brief Summary
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High altitude (>2400 m) is associated with decreased atmosphere pressure leading to hypoxia which in turn impairs exercise capacity and causes acute mountain sickness (AMS). It is noted that adding CO2 might be beneficial to improve hypoxia and exercise performance at high altitude. However, no device is currently available that can supply a constant low dose of CO2 during free movement at high altitude. We have recently invented a portable device which is small and light enough for supplement of low dose CO2 during field exercise at high altitude.

Detailed Description
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Objective: To determine whether the supplement of low-dose CO2 by the novel device could improve exercise performance at high altitude. Methods: The lowlanders (<500m) who have no history of travelling to high altitude (>1000m) a year before the study will be recruited. And the subjects who are high-altitude residents and have not left high altitude over the last twelve months will also be recruited for the study. Subjects will be randomly and blindly given either CO2 mixed with air or air alone during endurance shuttle walking test (ESWT). Blood gases will be measured before and after inhalation of CO2. ESWT time, ventilation per minute (VE), blood oxygen saturation (SPO2), and end-tidal CO2 concentration (ETCO2) will be measured during exercise and will be compared during inhalation of CO2 and during inhalation of ambient air.

Official Title
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Effect of Supplement of CO2 Using Novel Portable Device on Exercise Performance at High Altitude

Conditions
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High Altitude, Inhalation; Gas, Acute Mountain Sickness

Intervention / Treatment
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* Drug: Exercise under inhalation CO2
* Other: Exercise under inhalation ambient air


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy lowlanders (<500m) who have no history to travel to high altitude (>1000m) a year before the study. Healthy high altitude (4500m) residents who have not left the inhabited area over the last twelve months before the study. Exclusion Criteria: 1. Subjects with cardiovascular diseases, respiratory diseases and neuromuscular diseases which could affect exercise.

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Exercise under inhalation of CO2<br>Subjects will perform shuttle walk test under inhalation of low concentration of CO2 supplied by a novel device at high altitude. | Drug: Exercise under inhalation CO2<br>* Participants perform shuttle walk test at high altitude while using the novel portable device for inhalation of CO2<br>* Other names: inhalation of low dose CO2;|
| Placebo Comparator: Exercise under inhalation of ambient air<br>Subjects will perform shuttle walk test under inhalation of ambient air at high altitude. | Other: Exercise under inhalation ambient air<br>* Participants perform shuttle walk test at high altitude while inhaling ambient air<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of the distance in walking test | Changes in walking distance under inhalation of CO2 and ambient air | 48 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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High altitude, Exercise performance, CO2 inhalation