NCT03524053

Mediator Release During Exercise-induced Bronchoconstriction

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 12 (estimated)
• Sponsor: Brunel University · Academic / Other
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Not accepted

Summary

This study will compare the inflammatory response in induced vs inhibited exercise induced bronchoconstriction (EIB) in patients with a medical diagnosis of asthma/EIB. Urinary and plasma samples will be analysed to compare the mediator release in each condition, alongside changes in lung function.

Detailed description

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.

Conditions

• Exercise Induced Asthma

Interventions

Type	Name	Description
OTHER	Exercise induced bronchoconstriction	Participants will exercise whilst inhaling dry-air, this is known to exacerbate the bronchoconstrictive response.
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.

Timeline

• Start date: 2018-11-01
• Primary completion: 2020-03-01
• Completion: 2020-03-01
• First posted: 2018-05-14
• Last updated: 2019-01-29

Locations

1 site across 1 country: United Kingdom