N/A Completed N=60 Basic Science

Health Effects of Diesel Exhaust in Asthmatic Patients: A Real-world Study in a London Street

Source: ClinicalTrials.gov NCT00127062 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Oct 2019

Primary outcomePrimary: Spirometry, Percentage Change in FEV1 From Baseline — -1.0; -4.8; -2.2; -7.4 percentage change in FEV1 from baseline — p=<0.05

Summary

Acute exposure to diesel exhaust under normal city conditions leads to a worsening of symptoms of asthma, with reduction in lung function in asthmatic nonsmoking adults, dependent on the exposure dose and on the background severity of asthma. The worsening asthma is accompanied by increased oxidative stress and inflammation in the lungs.

Outcome Measures

Outcome	Result	p-value
PRIMARY Spirometry, Percentage Change in FEV1 From Baseline	-1.0; -4.8; -2.2; -7.4	<0.05 sig

Eligibility Criteria

Inclusion Criteria

Subjects will be selected according to the current severity of their asthma; thirty from Steps 1 and 2 and thirty from Step 3 of the World Health Organization (WHO) Global Initiative for Asthma (GINA) asthma guidelines. These will include mild and moderate asthmatic states. Depending on baseline FEV1, subjects will undergo either a methacholine bronchial hyperresponsiveness assessment or airways reversibility testing. Subjects with normal FEV1 (>80% predicted) or normal FEV1/FVC ratio will undergo methacholine challenge. Subjects with FEV1 <80% predicted will undergo airways reversibility testing. Subjects must have either a PC20 of less than 8mg/ml methacholine, or improvement in FEV1 of 12% or more, following inhalation of short acting β-agonist (salbutamol 200μg from metered dose inhaler [MDI]). Skin prick testing will be conducted for common allergens (house dust mite, grass pollen, aspergillus fumigatus and cat hair). The results will only be for descriptive purposes, not as subject inclusion/exclusion criteria. Subjects may be atopic or non-atopic (according to history and allergy testing).

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT00127062). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.