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

State Key Laboratory of Respiratory Disease

Status: Completed

Conditions: Inhalation; Gas; Acute Mountain Sickness; High Altitude

Treatments: Other: Exercise under inhalation ambient air; Drug: Exercise under inhalation CO2

Study type: Interventional

Funder types: Other

Identifiers

NCT05798416

2020 No.37

Details and patient eligibility

About

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.

Full description

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.

Enrollment: 28 patients

Sex: All

Ages: 18 to 70 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Healthy lowlanders (<500m) who have no history to travel to high altitude (>1000m) a year before the study.
2. 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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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28 participants in 2 patient groups, including a placebo group

Exercise under inhalation of CO2

Active Comparator group

Description:

Subjects will perform shuttle walk test under inhalation of low concentration of CO2 supplied by a novel device at high altitude.

Treatment:

Drug: Exercise under inhalation CO2

Exercise under inhalation of ambient air

Placebo Comparator group

Description:

Subjects will perform shuttle walk test under inhalation of ambient air at high altitude.

Treatment:

Other: Exercise under inhalation ambient air