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

Asthma Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00127062
• Other study ID #: 03-194
• Status: Completed
• Phase: N/A
• Start date: May 2003
• Est. completion date: August 2006

Study information

• Verified date: October 2019
• Source: Imperial College London
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Description:

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 60
• Est. completion date: August 2006
• Est. primary completion date: August 2006
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 55 Years

Eligibility

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 ß-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).

Related Conditions & MeSH terms

• Asthma

Intervention

Other:
• Oxford street
2 h walk around Oxford street
• Hyde park
2 h walk around Hyde park

Locations

Country	Name	City	State
n/a

Sponsors (2)

Lead Sponsor	Collaborator
Imperial College London	Health Effects Institute

References & Publications (1)

Zhang JJ, McCreanor JE, Cullinan P, Chung KF, Ohman-Strickland P, Han IK, Järup L, Nieuwenhuijsen MJ. Health effects of real-world exposure to diesel exhaust in persons with asthma. Res Rep Health Eff Inst. 2009 Feb;(138):5-109; discussion 111-23. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Spirometry, Percentage Change in FEV1 From Baseline		baseline, 24 hours after