Mediator Release During Exercise-induced Bronchoconstriction
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|ClinicalTrials.gov Identifier: NCT03524053|
Recruitment Status : Recruiting
First Posted : May 14, 2018
Last Update Posted : January 29, 2019
|Condition or disease||Intervention/treatment||Phase|
|Exercise Induced Asthma||Other: Exercise induced bronchoconstriction Other: Inhibited EIB||Not Applicable|
Exercise induced-bronchoconstriction (EIB) is a transient narrowing of the airways that occurs during or shortly after strenuous exercise. The prevalence of EIB in asthmatic patients is estimated around 30-50%, but EIB can also occur in individuals without asthma (especially children, army recruit forces, and elite athletes). Controversy remains about the causative mediators in the bronchoconstrictive response. Technological advancement in mass spectrometry has opened new avenues in the quantitative measurement of small endogenous metabolites in biological fluids (including urine and blood), which may provide insights into the pathophysiology of EIB and direct future therapeutic targets.
Utilising novel techniques in the analysis of inflammatory mediators in urine and blood, this study aims to conduct the most comprehensive analysis of mediator release during EIB to date.
Participants will attend a screening visit during which they will complete an exercise challenge (to determine the presence of EIB). A skin prick test will also be conducted to establish the atopic status of the participants. Following the screening visit, patients with EIB will be invited to complete a randomised cross-over study, where they will perform two further exercise challenges on separate days: one while inhaling temperate dry air, and one while inhaling hot humid air (the latter is known to inhibit EIB). Lung function and breathing discomfort will be recorded, and urine and blood samples will be collected, before and at various time points after exercise. As a control condition, participants will also attend one visit during which no exercise will be performed.
Participants aged 18-50yr, with diagnosed asthma and/or EIB, will be included in the study. 12 participants will complete 4 visits (lasting between 90 min and 4.5h). The study will take place on Brunel University London campus, Uxbridge. Urine and blood samples will be sent to the Karolinska Institutet, Stockholm, Sweden for analysis.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||12 participants|
|Intervention Model:||Crossover Assignment|
|Intervention Model Description:||Patients will undertake 3 separate conditions in a randomised order.|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Official Title:||Mediator Release During Exercise-induced Bronchoconstriction|
|Actual Study Start Date :||November 1, 2018|
|Estimated Primary Completion Date :||March 2020|
|Estimated Study Completion Date :||March 2020|
Experimental: Exercise induced bronchoconstriction
An exercise challenge will then be performed according to international guidelines. The exercise will consist of 8 minutes of cycling on a cycle ergometer while breathing medical grade dry air from a reservoir (Douglas bag) via a two-way non-rebreathing valve. The workload will be increased progressively over the first 2 minutes, and will then be maintained for 6 minutes at a target workload (in Watts) of [53.76 * measured forced expiratory volume in 1 sec (FEV1)-11.07].
Other: Exercise induced bronchoconstriction
Participants will exercise whilst inhaling dry-air, this is known to exacerbate the bronchoconstrictive response.
Other Name: Induced bronchoconstriction
Active Comparator: Inhibited EIB
An exercise challenge will then be performed according to international guidelines. The exercise will consist of 8 minutes of cycling on a cycle ergometer while warm-humid air from a reservoir (Douglas bag) via a two-way non-rebreathing valve. The workload will be increased progressively over the first 2 minutes, and will then be maintained for 6 minutes at a target workload (in Watts) of [53.76 * measured forced expiratory volume in 1 sec (FEV1)-11.07].
Other: Inhibited EIB
Participants will perform the exercise-test whilst inhaling warm-humid air. This is known to inhibit the EIB response and will provide a direct comparison group for the EIB condition.
Other Name: Exercise-control
No Intervention: Control
Participants will attend the laboratory but no exercise trial will be performed.
- Changes in the concentration of inflammatory mediator metabolites in urine [ Time Frame: Urine sample will be collected 45 minutes and immediately prior to the exercise challenges (or controlled resting period) and at 45, 90, 135 and 180 minutes post-exercise. ]Concentration of metabolites of prostaglandin-D2, Cysteinyl-Leukotrienes, prostaglandin-E2, prostacyclin, thromboxane and isoprostanes will be expressed as pg per mmol of creatinine.
- Changes in the concentration of inflammatory mediator metabolites in blood plasma [ Time Frame: Urine sample will be collected 45 minutes and immediately prior to the exercise challenges (or controlled resting period) and at 45, 90, 135 and 180 minutes post-exercise. ]Concentration of tryptase and pro-inflammatory cytokines measured from blood plasma samples.
- Forced vital capacity (FVC) manoeuvres using spirometry [ Time Frame: Spirometry will be performed 45 minutes and immediately prior to the exercise challenges (or controlled resting period) and at 45, 90, 135 and 180 minutes post-exercise. ]Forced expiratory volume in one second (FEV1) measured in litres will be used to determine the severity of EIB from baseline to post-exercise challenge.
- Breathing rate [ Time Frame: Continuous recording throughout 8-min exercise test using the online breath-by-breath analysis system. ]Breathing rate (breaths per minute) will be recorded throughout exercise to control intensity between trials.
- Heart rate [ Time Frame: Continuous recording continuously throughout the 8-min exercise test using short-range radiotelemetry using a chest belt worn by the participant. ]Heart rate (beats per minute) will be recorded throughout the exercise challenge test to control intensity between trials.
- Rating of breathing discomfort [ Time Frame: Breathing discomfort severity ratings will be recorded every 2 minutes throughout the 8 min exercise test (a total of 4 measurements) ]Modified Borg scale (0- no discomfort, 10- severe discomfort).
- Description of breathing discomfort [ Time Frame: A description of breathing discomfort will be recorded every 2 minutes throughout the 8 min exercise test (a total of 4 measurements) ]Descriptors from patients to describe the level of discomfort - i.e. 'my chest is tight'.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03524053
|Contact: Hannah Marshall, MScfirstname.lastname@example.org|
|Contact: Pascale Kippelen, PhDemail@example.com|
|Brunel University London||Recruiting|
|Uxbridge, Middlesex, United Kingdom, UB8 3PH|
|Contact: Hannah Marshall, MSc +447584168742 firstname.lastname@example.org|
|Contact: Pascale Kippelen, PhD 01895267649 email@example.com|
|Principal Investigator:||Hannah Marshall, MSc||Brunel University|