Diesel Exhaust Induces Glucocorticoid Resistance
Recruiting now Phase 4 NCT03615742
Run by University of British Columbia · for 19 to 49 · All sexes
What this study is about
The investigators are studying the effects of exposure to diesel exhaust on lung inflammation in the presence and absence of an inhaled corticosteroid. Although data is mixed, studies show that asthmatics have increased lung inflammation and worse symptoms during periods of higher air pollution despite taking their anti-inflammatory corticosteroid medication. One possible reason is that air pollution exposure may decrease the ability of corticosteroids to combat inflammation. To test this volunteers will inhale either a placebo or a corticosteroid, before sitting in an exposure booth for 2 hours breathing either filtered air or diluted diesel exhaust. Samples will be collected before and after exposure to analyze the effects of budesonide and diesel exhaust exposure.
Who can join (things the study team will check)
✅ You may be able to join if…
- Aged 19-49
- Have physician-diagnosed asthma confirmed by the study physician examination, spirometry, methacholine challenge provocative concentration causing a 20% fall (PC20) of <16 mg/mL, and questionnaires during a screening visit
🚫 You may not be able to join if…
- Smoking of any kind (0.5 pack-years ever, or any current) or use of vape/vaporizing devices
- Regular anti-histamine, NSAID, corticosteroid or other controller medication use
- Pregnancy or breastfeeding
- Methacholine PC20 >16
- Relevant cardiac condition or arrhythmia
- Body mass index of >35
- Currently participating in another study that may interfere with this study
- Use of either inhaled or oral corticosteroids in preceding 6 months
- Substantial comorbidities on study physician's examination or other concerns
- Surgery scheduled before anticipated study completion
Where this trial is running
- University of British Columbia, Vancouver, British Columbia, Canada
Who to contact
Parteek (PJ) Johal, BCS · 6048755132 · de.study@ubc.ca
It's completely normal to call and ask questions before deciding anything. Mention the study ID: NCT03615742.
Verify everything on the official ClinicalTrials.gov record. Page updated July 2026.