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

University of British Columbia40 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

Conditions

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

Eligibility

Sex: ALLMin age: 18 YearsMax age: 50 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Change in FEV1 from baseline to 10 minutes after exercise

Measurement of pulmonary function: forced exhaled volume in the first second (FEV1) in liters

Time frame: 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

Time frame: 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)

Time frame: Measured at baseline and 10 minutes after each exercise bout

Secondary Outcomes

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

Time frame: 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)

Time frame: Measured at baseline and 5 minutes after each exercise bout

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

Overview

Conditions

Interventions

Eligibility

Locations (2)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts