Exercise-induced Bronchoconstriction, Air Pollution
Conditions
Keywords
Exercise-induced bronchoconstriction, Air pollution, Exercise, Inhaled beta-2-agonist, Cognitive Function
Brief summary
When exposed to air pollution, the asthma symptoms are aggravated and lung function is impaired. Due to high breathing rates and volumes, physically active individuals are at particular risk of lung health impairment due to the high breathing rates and volumes. Greater doses of air pollutants reach deeper areas in the lungs where they can trigger asthma-symptoms. When treating these symptoms with inhaled beta-2-agonists the airways widen even more, allowing the air pollutants to reach even deeper areas of the lung. With this study the investigators investigate how inhaled beta-2-agonists affect athletic capacity and lung health in physically active asthmatics.
Interventions
OTHERRest (Sitting on chair)
Study participants will sit on a chair for 60min. This is to simulate physical resting condition.
OTHERCycling exercise
Study participants will exercise on a cycle ergometer for 45min. Participants will start their 30-min long constant workload exercise test test 60-min after the drug intervention. The exercise test will be set to a resistance of 50% of the maximal wattage that was reached on the graded exercise test on the screening day. The cycling exercise intervention will follow the rest-intervention.
DRUGSalbutamol inhalation
Study participants will be exposed to 400ug of salbutamol prior to entering the air pollution chamber.
Study participants will inhale a placebo (placebo for salbutamol) prior to entering the air pollution chamber
Participants will be exposed to PM2.5 of 300 μg/m3
OTHERFiltered air
Participants will be breathing filtered air
Sponsors
Canadian Academy of Sport and Exercise Medicine (CASEM)
Natural Sciences and Engineering Research Council, Canada
Fraser Basin Council
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
19 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* mild-moderate asthmatics with controlled treatment (definition of mild: percent fall index at eucapnic voluntary hyperpnea (EVH) test on screening day between 10-15%; moderate: percent fall index at EVH test on screening day between 15 - 20%). * men and non-pregnant women
Exclusion criteria
* any history of uncontrolled respiratory or cardiac disease * pregnancy * allergic reactions to lidocaine and salbutamol * any recent infections or orthopaedic nasal issues/injuries that may interfere with the insertion of the catheter needed to assess expiratory flow limitation or work of breathing * claustrophobia in small rooms, comparable to the air pollution chamber used for this study. * English as a second language (ESL) - participants who are not able to understand the risk that may be associated with the participation in this study due to language difficulties after following the University of British Clinical Research Ethics Board Guidance Notes 13.2.1. (ESL participants will be given a consent form in the most appropriate language or an appropriate translator will be present during the initial consent process).
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in rating of perceived exertion for breathing, dyspnea | Difference in perceived dyspnea between salbutamol and placebo exposure as well as polluted air and filtered air. Dyspnea ratings will be collected every 2.5min for a duration of 45min during the exercise test. |
Secondary
| Measure | Time frame |
|---|---|
| Change in work of breathing (WOB) between filtered air and polluted air | work of breathing will be assessed every 2.5min for a time period of 45min during the exercise bout |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change in spirometry (FEV1 and FVC) between filtered air and polluted air | Spirometry will be assessed at baseline and 45min after the start of the exercise bout. | — |
| Change in cognitive function | Cognitive function will be assessed at baseline (prior to entering the air pollution chamber) and 45 min after the start of the exercise intervention. | cognitive function will be assessed using the NIH toolbox tests and the brain derived neurotrophic factor (BDNF) blood serum measurements |
| Retinal Imaging | The retina will be imaged at baseline (prior to entering the air pollution chamber) and 20 min after the completion of the exercise intervention. | The blood vessels in the eye will be imaged using a camera. |
Countries
Canada
Outcome results
None listed