Adaptation to Ozone in Individuals With Asthma/Exercise-induced Bronchoconstriction

Study Overview
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Brief Summary
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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.

Official Title
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Pulmonary and Vascular Adaptations to a 5-days Exercise Protocol in Ozone in Physically Active Individuals With Asthma and Exercise-induced Bronchoconstriction

Conditions
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Asthma, Asthma, Exercise-Induced, Exercise Induced Asthma, Exercise Induced Bronchospasm

Intervention / Treatment
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* Behavioral: Exercise
* Other: Ozone
* Other: Filtere Air


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ozone (O3) group<br>Participants of the experimental group will perform sub-maximal exercise (60% of VO2max for 30 minutes) on a cycle ergometer while inhaling 170ppb ozone delivered continuously during each exercise session. | Behavioral: Exercise<br>* Cycling at 60% of VO2max on a cycle ergometer for 30 minutes<br>Other: Ozone<br>* Breathing 170ppb ozone<br>|
| Sham Comparator: Filtered Air<br>Participants of the sham group will also perform sub-maximal exercise (60% of VO2max for 30 minutes) on a cycle ergometer similar to intervention. However, only in this group, the ozone generator will not be activated so that just filtered air will be delivered to the participant while performing each exercise session. | Behavioral: Exercise<br>* Cycling at 60% of VO2max on a cycle ergometer for 30 minutes<br>Other: Filtere Air<br>* Breathing filtered air<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in FEV1 from baseline to 10 minutes after exercise | Measurement of pulmonary function: forced exhaled volume in the first second (FEV1) in liters | Measured at baseline and 10 minutes after each exercise bout | 
| Change in FVC from baseline to 10 minutes after exercise | Measurement of pulmonary function: forced vital capacity (FVC) in liters | Measured at baseline and 10 minutes after each exercise bout | 
| Change in FEF25-75 from baseline to 10 minutes after exercise | Measurement of pulmonary function: forced expiratory flow at 25-75% of pulmonary volume in liters per second (L/s) | Measured at baseline and 10 minutes after each exercise bout | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Pulse Wave Velocity (PWV) from baseline to 20 minutes after exercise | Velocity (in meters per second) at which the blood pressure pulse propagates through set points in the circulatory system | Measured at baseline and 20 minutes after each exercise bout | 
| Change in Fraction of exhaled nitric oxide (FeNO) from baseline to 5 minutes after exercise | Non-invasive airway inflammation biomarker (in part per billion, ppb) | Measured at baseline and 5 minutes after each exercise bout | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ozone, Air pollution, Asthma, Exercise-induced bronchoconstriction