Diesel Exhaust and Mechanism of Asthma

Asthma Clinical Trial

Official title: Effects of Diesel Exhaust on Airways

Status Completed

Clinical Trial Summary

This experiment is designed to test the hypothesis that oxidative stress is responsible for changes in airway responsiveness in humans exposed to diesel exhaust.

Clinical Trial Description

The specific aim is to test the hypothesis that diesel exhaust (DE) increases airway reactivity via oxidative stress, particularly in asthmatics. To test this hypothesis, we use a crossover in vivo experimental model in mild asthmatics and normal controls using a state-of-the-art diesel exhaust exposure facility.

Participants took N-acetylcysteine (600 mg) or placebo capsules three times daily for six days. On the final morning of supplementation, participants were exposed for 2 hours to either filtered air or diesel exhaust (300 µg·m-3 of particulate matter smaller than 2.5 microns). Twenty-six non-smokers between 19-49 years were studied under three experimental conditions (filtered air with placebo, diesel exhaust with placebo and diesel exhaust with N-acetylcysteine) using randomized, double-blind, crossover design, with a two week minimum washout between conditions. Methacholine challenge was performed pre-exposure (to determine baseline airway responsiveness) and post-exposure (to determine the effect of exposure). ;

Related Conditions & MeSH terms

• Asthma

• NCT number: NCT01699204
• Study type: Interventional
• Source: University of British Columbia
• Status: Completed
• Phase: N/A
• Start date: September 2007
• Completion date: October 2011