Exercise in Air Pollution and Lung Health in Asthmatics

University of British Columbia20 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

Conditions

Exercise-induced Bronchoconstriction Air Pollution

Interventions

Cycling exerciseOTHER

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.

Eligibility

Sex: ALLMin age: 19 YearsMax age: 40 YearsHealthy volunteers:

Medical Language ↔ Plain English

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).

Outcomes

Primary Outcomes

Change in rating of perceived exertion for breathing, dyspnea

Time frame: 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 Outcomes

Change in work of breathing (WOB) between filtered air and polluted air

Time frame: work of breathing will be assessed every 2.5min for a time period of 45min during the exercise bout