Asthma, Asthma, Exercise-Induced, Exercise Induced Asthma, Exercise Induced Bronchospasm
Conditions
Keywords
Ozone, Air pollution, Asthma, Exercise-induced bronchoconstriction
Brief summary
Researchers found that impairments in the cardiopulmonary system caused by acute exposure to ozone were outweighed by repeated exposures to ozone. The goal of this study is to confirm there will be an adaptation similar to what was previously proved but in individuals with asthma and exercise-induced bronchoconstriction (EIB). The purpose is to examine adaptive responses in a randomized cross-over trial in which physically active individuals will perform submaximal exercise on five days in ozone and filtered air exposures separated by a washout period.
Interventions
BEHAVIORALExercise
Cycling at 60% of VO2max on a cycle ergometer for 30 minutes
OTHEROzone
Breathing 170ppb ozone
OTHERFiltere Air
Breathing filtered air
Sponsors
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Air quality condition (Ozone and filtered air) will be double-blinded; Participants will not be told at any time before the study completion to which group they are assigned (intervention or sham)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* Recreationally active individuals * Diagnosed asthma and/or mild exercise-induced bronchoconstriction: defined by an FEV1 fall equal to or greater than 10% but lower than 25% in the eucapnic hyperventilatory test. * Able to securely perform a maximal exercise test (responded 'no' to all questions on the PAR-Q+ questionnaire) * Able to communicate in English
Exclusion criteria
* Diagnosed with any cardiorespiratory or vascular diseases * Pregnant or potentially pregnant * Non-smoking * Lower limb musculoskeletal injury or lower limb limitation to cycle on a bicycle ergometer * Recent respiratory symptoms or upper tract infection within 4 weeks * On vitamin (e.g., C or E) supplementation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in FEV1 from baseline to 10 minutes after exercise | Measured at baseline and 10 minutes after each exercise bout | Measurement of pulmonary function: forced exhaled volume in the first second (FEV1) in liters |
| Change in FVC from baseline to 10 minutes after exercise | Measured at baseline and 10 minutes after each exercise bout | Measurement of pulmonary function: forced vital capacity (FVC) in liters |
| Change in FEF25-75 from baseline to 10 minutes after exercise | Measured at baseline and 10 minutes after each exercise bout | Measurement of pulmonary function: forced expiratory flow at 25-75% of pulmonary volume in liters per second (L/s) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Pulse Wave Velocity (PWV) from baseline to 20 minutes after exercise | Measured at baseline and 20 minutes after each exercise bout | Velocity (in meters per second) at which the blood pressure pulse propagates through set points in the circulatory system |
| Change in Fraction of exhaled nitric oxide (FeNO) from baseline to 5 minutes after exercise | Measured at baseline and 5 minutes after each exercise bout | Non-invasive airway inflammation biomarker (in part per billion, ppb) |
Countries
Canada
Contacts
Primary ContactPatric O Gonçalves, BScPT
Backup ContactMichael Koehle
Outcome results
None listed