AsthmaNCT01699204
Diesel Exhaust and Mechanism of Asthma
A study testing N-acetylcysteine, Diesel exhaust and Filtered air in people with Asthma, run by University of British Columbia at 1 site in Canada.
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. Read more about this study
- Who is it for?
- Ages 19 to 49 yearsHealthy volunteers can take part
- Conditions the study is for
- Asthma
- What is being tested?
- N-acetylcysteine, Diesel exhaust and Filtered air
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 26 participants
- Where
- 1 siteCanada
- Study dates
- Sep 2007to Oct 2011
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 to 49 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Between 19-49 years, non smokers, asthmatics, healthy controls
Who cannot join
- Smokers, pregnant or co-existing medical condition for which diesel exhaust would confer significant risk (i.e. coronary artery disease)
Trial locations and contacts
1 site in 1 country.
Canada1 site
University of British Columbia
Vancouver, British Columbia, V5Z1M9
About this study
Official title: Effects of Diesel Exhaust on Airways
This experiment is designed to test the hypothesis that oxidative stress is responsible for changes in airway responsiveness in humans exposed to diesel exhaust.
Read the detailed 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).
- Conditions
- Asthma
- Being tested
- N-acetylcysteine, Diesel exhaust, Filtered air
- Keywords
- Air pollution, Diesel exhaust, Airway responsiveness, Asthma, Anti-oxidant
- Medical subject headings
- Asthma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
N-acetylcysteineDietary supplement
N-acetylcysteine 600mg taken orally 3 times daily for 6 days prior to exposure to diesel exhaust for 2 hours. The last supplement was taken the morning of the exposure
Diesel exhaustOther
A placebo tablet taken 3 times daily for 6 days prior to exposure to diesel exhaust for 2 hours. The last supplement was taken the morning of the exposure
Filtered airOther
A placebo tablet taken 3 times daily for 6 days prior to exposure to filtered air for 2 hours. The last supplement was taken the morning of the exposure
| Study group | Role | What they receive |
|---|---|---|
| Filtered air with placebo | Placebo comparator | Exposure for 2 hours to filtered air and placebo tablets 3 times daily for 6 days Receives: Other: Filtered air |
| Diesel exhaust with placebo | Active comparator | Exposure for 2 hours to diesel exhaust and placebo tablets 3 times daily for 6 days Receives: Other: Diesel exhaust |
| Diesel exhaust with N-acetylcysteine | Experimental | Exposure for 2 hours to diesel exhaust and N-acetylcysteine tablets (600 mg) 3 times daily for 6 days Receives: Dietary Supplement: N-acetylcysteine; Other: Diesel exhaust |
What is being measured
The primary outcome is the main question the study is designed to answer.
Human airway reactivity
Establish that oxidative stress is responsible for changes in human airway reactivity induced by DE (300 µg/m3 inhaled for two hours).
Measured: 50 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Oct 2012 (estimated)
- Study startSep 2007
- Primary completionOct 2011
- Study completionOct 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for AsthmaStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Christopher Carlsten, University of British Columbia
- Investigators
- Christopher Carlsten, MD MPH, Principal investigator, University of British Columbia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01699204
- Sponsor's protocol ID
- H08-02288
- Status last verified
- Sep 2017
- First submitted
- 1 Oct 2012
- Last updated
- 29 Sep 2017
- Results posted
- No
- Data monitoring committee
- No
Publications
Braman SS. The global burden of asthma. Chest. 2006 Jul;130(1 Suppl):4S-12S. doi: 10.1378/chest.130.1_suppl.4S.
PubMed 16840363Atkinson RW, Anderson HR, Sunyer J, Ayres J, Baccini M, Vonk JM, Boumghar A, Forastiere F, Forsberg B, Touloumi G, Schwartz J, Katsouyanni K. Acute effects of particulate air pollution on respiratory admissions: results from APHEA 2 project. Air Pollution and Health: a European Approach. Am J Respir Crit Care Med. 2001 Nov 15;164(10 Pt 1):1860-6. doi: 10.1164/ajrccm.164.10.2010138.
PubMed 11734437Janssen NA, Brunekreef B, van Vliet P, Aarts F, Meliefste K, Harssema H, Fischer P. The relationship between air pollution from heavy traffic and allergic sensitization, bronchial hyperresponsiveness, and respiratory symptoms in Dutch schoolchildren. Environ Health Perspect. 2003 Sep;111(12):1512-8. doi: 10.1289/ehp.6243.
PubMed 12948892Mudway IS, Stenfors N, Duggan ST, Roxborough H, Zielinski H, Marklund SL, Blomberg A, Frew AJ, Sandstrom T, Kelly FJ. An in vitro and in vivo investigation of the effects of diesel exhaust on human airway lining fluid antioxidants. Arch Biochem Biophys. 2004 Mar 1;423(1):200-12. doi: 10.1016/j.abb.2003.12.018.
PubMed 14871482Rudell B, Ledin MC, Hammarstrom U, Stjernberg N, Lundback B, Sandstrom T. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust. Occup Environ Med. 1996 Oct;53(10):658-62. doi: 10.1136/oem.53.10.658.
PubMed 8943829Stenfors N, Nordenhall C, Salvi SS, Mudway I, Soderberg M, Blomberg A, Helleday R, Levin JO, Holgate ST, Kelly FJ, Frew AJ, Sandstrom T. Different airway inflammatory responses in asthmatic and healthy humans exposed to diesel. Eur Respir J. 2004 Jan;23(1):82-6. doi: 10.1183/09031936.03.00004603.
PubMed 14738236Hashimoto S, Gon Y, Takeshita I, Matsumoto K, Jibiki I, Takizawa H, Kudoh S, Horie T. Diesel exhaust particles activate p38 MAP kinase to produce interleukin 8 and RANTES by human bronchial epithelial cells and N-acetylcysteine attenuates p38 MAP kinase activation. Am J Respir Crit Care Med. 2000 Jan;161(1):280-5. doi: 10.1164/ajrccm.161.1.9904110.
PubMed 10619832McCreanor J, Cullinan P, Nieuwenhuijsen MJ, Stewart-Evans J, Malliarou E, Jarup L, Harrington R, Svartengren M, Han IK, Ohman-Strickland P, Chung KF, Zhang J. Respiratory effects of exposure to diesel traffic in persons with asthma. N Engl J Med. 2007 Dec 6;357(23):2348-58. doi: 10.1056/NEJMoa071535.
PubMed 18057337
Study at a glance
From the registry record, last updated by the sponsor on 29 Sep 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Diesel Exhaust on Airways
- ClinicalTrials.gov ID
- NCT01699204
- Acronym / sponsor ID
- H08-02288
- Conditions
- Asthma
- Keywords
- Air pollution, Diesel exhaust, Airway responsiveness, Asthma, Anti-oxidant
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 26 participants (actual)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Study start
- Sep 2007
- Primary completion
- Oct 2011 (actual)
- Study completion
- Oct 2011 (actual)
- First posted
- 3 Oct 2012 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This experiment is designed to test the hypothesis that oxidative stress is responsible for changes in airway responsiveness in humans exposed to diesel exhaust.
Detailed 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).
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Filtered air with placebo | Placebo comparator | Other: Filtered airExposure for 2 hours to filtered air and placebo tablets 3 times daily for 6 days |
| Diesel exhaust with placebo | Active comparator | Other: Diesel exhaustExposure for 2 hours to diesel exhaust and placebo tablets 3 times daily for 6 days |
| Diesel exhaust with N-acetylcysteine | Experimental | Dietary Supplement: N-acetylcysteine, Other: Diesel exhaustExposure for 2 hours to diesel exhaust and N-acetylcysteine tablets (600 mg) 3 times daily for 6 days |
Who may qualify
- Ages
- 19 to 49 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Between 19-49 years, non smokers, asthmatics, healthy controls
Key exclusion criteria (1 listed)
- Smokers, pregnant or co-existing medical condition for which diesel exhaust would confer significant risk (i.e. coronary artery disease)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| N-acetylcysteineN-acetylcysteine 600mg taken orally 3 times daily for 6 days prior to exposure to diesel exhaust for 2 hours. The last supplement was taken the morning of the exposure | Dietary supplement | Diesel exhaust with N-acetylcysteine |
| Diesel exhaustA placebo tablet taken 3 times daily for 6 days prior to exposure to diesel exhaust for 2 hours. The last supplement was taken the morning of the exposure | Other | Diesel exhaust with N-acetylcysteine, Diesel exhaust with placebo |
| Filtered airA placebo tablet taken 3 times daily for 6 days prior to exposure to filtered air for 2 hours. The last supplement was taken the morning of the exposure | Other | Filtered air with placebo |
Primary outcome
Human airway reactivity
Time frame: 50 hours
Establish that oxidative stress is responsible for changes in human airway reactivity induced by DE (300 µg/m3 inhaled for two hours).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Sep 2017.
- Background: PubMed 16840363Braman SS. The global burden of asthma. Chest. 2006 Jul;130(1 Suppl):4S-12S. doi: 10.1378/chest.130.1_suppl.4S.
- Background: PubMed 11734437Atkinson RW, Anderson HR, Sunyer J, Ayres J, Baccini M, Vonk JM, Boumghar A, Forastiere F, Forsberg B, Touloumi G, Schwartz J, Katsouyanni K. Acute effects of particulate air pollution on respiratory admissions: results from APHEA 2 project. Air Pollution and Health: a European Approach. Am J Respir Crit Care Med. 2001 Nov 15;164(10 Pt 1):1860-6. doi: 10.1164/ajrccm.164.10.2010138.
- Background: PubMed 12948892Janssen NA, Brunekreef B, van Vliet P, Aarts F, Meliefste K, Harssema H, Fischer P. The relationship between air pollution from heavy traffic and allergic sensitization, bronchial hyperresponsiveness, and respiratory symptoms in Dutch schoolchildren. Environ Health Perspect. 2003 Sep;111(12):1512-8. doi: 10.1289/ehp.6243.
- Background: PubMed 14871482Mudway IS, Stenfors N, Duggan ST, Roxborough H, Zielinski H, Marklund SL, Blomberg A, Frew AJ, Sandstrom T, Kelly FJ. An in vitro and in vivo investigation of the effects of diesel exhaust on human airway lining fluid antioxidants. Arch Biochem Biophys. 2004 Mar 1;423(1):200-12. doi: 10.1016/j.abb.2003.12.018.
- Background: PubMed 8943829Rudell B, Ledin MC, Hammarstrom U, Stjernberg N, Lundback B, Sandstrom T. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust. Occup Environ Med. 1996 Oct;53(10):658-62. doi: 10.1136/oem.53.10.658.
- Background: PubMed 14738236Stenfors N, Nordenhall C, Salvi SS, Mudway I, Soderberg M, Blomberg A, Helleday R, Levin JO, Holgate ST, Kelly FJ, Frew AJ, Sandstrom T. Different airway inflammatory responses in asthmatic and healthy humans exposed to diesel. Eur Respir J. 2004 Jan;23(1):82-6. doi: 10.1183/09031936.03.00004603.
- Background: PubMed 10619832Hashimoto S, Gon Y, Takeshita I, Matsumoto K, Jibiki I, Takizawa H, Kudoh S, Horie T. Diesel exhaust particles activate p38 MAP kinase to produce interleukin 8 and RANTES by human bronchial epithelial cells and N-acetylcysteine attenuates p38 MAP kinase activation. Am J Respir Crit Care Med. 2000 Jan;161(1):280-5. doi: 10.1164/ajrccm.161.1.9904110.
- Background: PubMed 18057337McCreanor J, Cullinan P, Nieuwenhuijsen MJ, Stewart-Evans J, Malliarou E, Jarup L, Harrington R, Svartengren M, Han IK, Ohman-Strickland P, Chung KF, Zhang J. Respiratory effects of exposure to diesel traffic in persons with asthma. N Engl J Med. 2007 Dec 6;357(23):2348-58. doi: 10.1056/NEJMoa071535.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Christopher Carlsten, MD MPH principal investigator
University of British Columbia
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing N-acetylcysteine, Diesel exhaust and Filtered air in people with Asthma, run by University of British Columbia at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Sep 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Human airway reactivity (time frame: 50 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01699204, which also lists 8 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Sep 2017.