Exercise in Air Pollution and Lung Health in Asthmatics

The Effects of Inhaled Beta-2-Agonists and Air Pollution on Lung Function and Athletic Capacity

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.

Study Overview

• Status: Completed
• Conditions: Air Pollution; Exercise-induced Bronchoconstriction
• Intervention / Treatment: Other: Rest (Sitting on chair); Drug: Salbutamol inhalation; Other: Diesel Exhaust Exposure; Drug: Placebo inhalation; Other: Cycling exercise; Other: Filtered air

• Study Type: Interventional
• Enrollment (Anticipated): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Vancouver, British Columbia, Canada, V6T 1Z1
      • University of British Columbia, Environmental Physiology Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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).

Study Plan

How is the study designed?

Design Details

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

Number of Arms

8

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Resting in diesel exhaust following salbutamol inhalation; Participants will be sitting in an air pollution chamber while being exposed to diesel exhaust (PM2.5 of 300 μg/m3) for a total of 1hour following the inhalation of 400ug of salbutamol.	Other: Rest (Sitting on chair); Study participants will sit on a chair for 60min. This is to simulate physical resting condition.; Drug: Salbutamol inhalation; Study participants will be exposed to 400ug of salbutamol prior to entering the air pollution chamber.; Other: Diesel Exhaust Exposure; Participants will be exposed to PM2.5 of 300 μg/m3
Placebo Comparator: Resting in diesel exhaust following placebo inhalation; Participants will be sitting in an air pollution chamber while being exposed to diesel exhaust (PM2.5 of 300 μg/m3) for a total of 1hour following the inhalation of a placebo.	Other: Rest (Sitting on chair); Study participants will sit on a chair for 60min. This is to simulate physical resting condition.; Other: Diesel Exhaust Exposure; Participants will be exposed to PM2.5 of 300 μg/m3; Drug: Placebo inhalation; Study participants will inhale a placebo (placebo for salbutamol) prior to entering the air pollution chamber
Active Comparator: Cycling in diesel exhaust following salbutamol inhalation; Participants will be cycling while being exposed to diesel exhaust (PM2.5 of 300 μg/m3) for a total of 1 hr following the inhalation of 400ug of salbutamol.	Drug: Salbutamol inhalation; Study participants will be exposed to 400ug of salbutamol prior to entering the air pollution chamber.; Other: Diesel Exhaust Exposure; Participants will be exposed to PM2.5 of 300 μg/m3; Other: Cycling 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.
Placebo Comparator: Cycling in diesel exhaust following placebo inhalation; Participants will be cycling while being exposed to diesel exhaust (PM2.5 of 300 μg/m3) for a total of 1 hr following the inhalation of a placebo	Other: Diesel Exhaust Exposure; Participants will be exposed to PM2.5 of 300 μg/m3; Drug: Placebo inhalation; Study participants will inhale a placebo (placebo for salbutamol) prior to entering the air pollution chamber; Other: Cycling 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.
Sham Comparator: Resting in filtered air following salbutamol inhalation; Participants will be sitting while being exposed to filtered air for a total of 1hour following the inhalation of 400ug of salbutamol.	Other: Rest (Sitting on chair); Study participants will sit on a chair for 60min. This is to simulate physical resting condition.; Other: Filtered air; Participants will be breathing filtered air
Placebo Comparator: Resting in filtered air following placebo inhalation; Participants will be sitting while being exposed to filtered air for a total of 1hour following the inhalation of a placebo.	Other: Rest (Sitting on chair); Study participants will sit on a chair for 60min. This is to simulate physical resting condition.; Other: Filtered air; Participants will be breathing filtered air
Sham Comparator: Cycling in filtered air following salbutamol inhalation; Participants will be cycling while being exposed to filtered air for a total of 1 hr following the inhalation of 400ug of salbutamol.	Drug: Salbutamol inhalation; Study participants will be exposed to 400ug of salbutamol prior to entering the air pollution chamber.; Other: Cycling 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.; Other: Filtered air; Participants will be breathing filtered air
Placebo Comparator: Cycling in filtered air following placebo inhalation; Participants will be cycling while being exposed to filtered air for a total of 1 hr following the inhalation of a placebo	Drug: Placebo inhalation; Study participants will inhale a placebo (placebo for salbutamol) prior to entering the air pollution chamber; Other: Cycling 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.; Other: Filtered air; Participants will be breathing filtered air

What is the study measuring?

Primary Outcome Measures

Outcome 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 Outcome Measures

Outcome 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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 using the NIH toolbox tests and the brain derived neurotrophic factor (BDNF) blood serum measurements	Cognitive function will be assessed at baseline (prior to entering the air pollution chamber) and 45 min after the start of the exercise intervention.
Retinal Imaging	The blood vessels in the eye will be imaged using a camera.	The retina will be imaged at baseline (prior to entering the air pollution chamber) and 20 min after the completion of the exercise intervention.

Collaborators and Investigators

• Sponsor: University of British Columbia
• Collaborators: Natural Sciences and Engineering Research Council, Canada; Canadian Academy of Sport and Exercise Medicine (CASEM); Fraser Basin Council

Study record dates

Study Major Dates

• Study Start: May 1, 2015
• Primary Completion (Actual): August 1, 2016
• Study Completion (Actual): May 1, 2021

Study Registration Dates

• First Submitted: September 16, 2014
• First Submitted That Met QC Criteria: September 29, 2014
• First Posted (Estimate): September 30, 2014

Study Record Updates

• Last Update Posted (Actual): September 30, 2021
• Last Update Submitted That Met QC Criteria: September 28, 2021
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Keywords: Exercise; Air pollution; Cognitive Function; Exercise-induced bronchoconstriction; Inhaled beta-2-agonist
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Adrenergic Agonists; Bronchodilator Agents; Anti-Asthmatic Agents; Respiratory System Agents; Reproductive Control Agents; Adrenergic beta-2 Receptor Agonists; Adrenergic beta-Agonists; Tocolytic Agents; Albuterol
• Other Study ID Numbers: H13-01079