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

Study Results

Results available

Outcome measurements, participant flow, baseline characteristics, and adverse events have been published for this study.

View full results

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

60 participants

Study Classification

INTERVENTIONAL

Study Start Date

2003-05-31

Study Completion Date

2006-08-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

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.

Related Clinical Trials

Explore similar clinical trials based on study characteristics and research focus.

Children's Exposures/Health Effects/Diesel Exhaust

NCT00527345

Asthma Airway Inflammation

COMPLETED

Diesel Exhaust and Mechanism of Asthma

NCT01699204

Asthma

COMPLETED NA

Diesel Exhaust Inhalation, Systemic Nitric Oxide Inhibition and Cardiac Output

NCT01060930

Vascular Function in Healthy Volunteers

COMPLETED NA

Diesel Exhaust and Vascular Function

NCT01508637

Cardiovascular Effects

UNKNOWN NA

Effect of Diesel Exhaust Particulate Exposures on Endothelial Function in Humans

NCT00434005

Healthy

COMPLETED NA

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

The investigators will recruit 60 nonsmoking asthmatics of mild and of moderate severity. They will be exposed to Oxford St. or to Hyde Park for 2 hours each, at a walking pace. Real time exposure to PM2.5, carbon monoxide and nitrogen dioxide will be made each time. Health outcome measurements will be made before and after exposure to each street. Statistical analyses will be made to examine the effect of diesel exposure on changes in health outcome measures.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Asthma

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Asthma

Asthma patients ranging from mild to severe

Group Type EXPERIMENTAL

Oxford street

Intervention Type OTHER

2 h walk around Oxford street

Hyde park

Intervention Type OTHER

2 h walk around Hyde park

Healthy Non-Smokers

Group Type OTHER

Oxford street

Intervention Type OTHER

2 h walk around Oxford street

Hyde park

Intervention Type OTHER

2 h walk around Hyde park

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Oxford street

2 h walk around Oxford street

Intervention Type OTHER

Hyde park

2 h walk around Hyde park

Intervention Type OTHER

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion 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).

Minimum Eligible Age

18 Years

Maximum Eligible Age

55 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No