Endothelial DysfunctionNCT00845767
The Cardiovascular Effects of Air Pollution: the Role of Nitric Oxide
A study testing Forearm Vascular Study in people with Endothelial Dysfunction, run by University of Edinburgh at 1 site in Sweden.
Trial summary
Exposure to air pollution has been linked to increased cardiorespiratory morbidity and mortality. The exact component of air pollution that mediates this effect is unknown, but the link is strongest for fine combustion derived particulate matter derived from traffic sources. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Endothelial Dysfunction
- What is being tested?
- Forearm Vascular Study
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteSweden
- Study dates
- Apr 2009to Jul 2009
- 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 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy volunteers
Who cannot join
- Use of regular medication (except oral contraceptive pill)
- Current smokers
- Significant occupational exposure to air pollution
- Intercurrent illness
Trial locations and contacts
1 site in 1 country.
About this study
Exposure to air pollution has been linked to increased cardiorespiratory morbidity and mortality. The exact component of air pollution that mediates this effect is unknown, but the link is strongest for fine combustion derived particulate matter derived from traffic sources. Recently, it has been demonstrated that inhalation of diesel exhaust impairs vascular vasomotor tone and endogenous fibrinolysis. The mechanism underlying these detrimental vascular is unclear, but is thought to be via oxidative stress and altered bioavailability of endogenous nitric oxide. In these studies we plan to elucidate the role of endogenous nitric oxide (NO) in the adverse vascular responses observed following exposure to diesel exhaust.
- Conditions
- Endothelial Dysfunction
- Being tested
- Forearm Vascular Study
- Keywords
- Nitric Oxide, Nitric Oxide Synthase, Air Pollution, Endothelial Dysfunction, Diesel Exhaust
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Forearm Vascular StudyProcedure or surgery
Also called ACh, SNP, BK
Forearm venous occlusion plethysmography during intraarterial infusion of L-NMMA (2-8 µmol/min) followed by co-infusion of sodium nitroprusside (90-900 ng/min) as a "nitric oxide clamp". Forearm blood flow then measured during the clamp in response to infused vasodilators acetylcholine (5-20 mg/min), bradykinin (100-1000 pmol/min), verapamil (10-100 µg/min) and sodium nitroprusside (2-8 µg/min).
| Study group | Role | What they receive |
|---|---|---|
| Diesel Exposure | Experimental | 1 hour exposure to dilute diesel exhaust at a concentration of 300 µg/m3 with intermittent exercise Receives: Procedure: Forearm Vascular Study |
| Air Exposure | Experimental | 1 hour exposure to filtered air during intermittent exercise Receives: Procedure: Forearm Vascular Study |
What is being measured
The primary outcome is the main question the study is designed to answer.
Forearm blood flow as measured by venous occlusion plethysmography during infusion of NOS inhibitors and vasodilators
Measured: 2-4 hours after exposure
Secondary outcomes (2)
Plasma nitrite concentrations
Measured: During forearm study
Plasma concentrations of t-PA and PAI
Measured: After infusion of bradykinin during forearm study
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Feb 2009 (estimated)
- Study startApr 2009
- Primary completionJul 2009
- Study completionJul 2009
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Endothelial DysfunctionStudies of the same condition, open and under way.
- More trials run by University of EdinburghThe 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 16 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Edinburgh
- Sponsor type
- University, hospital or other
- Collaborators
- Umeå University
- Investigators
- Anders Blomberg, MD PhD, Principal investigator, Umeå UniversityDavid E Newby, PhD FRCP, Principal investigator, University of Edinburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00845767
- Sponsor's protocol ID
- DNR 08-185M/1
- Status last verified
- Oct 2009
- First submitted
- 17 Feb 2009
- Last updated
- 9 Oct 2009
- Results posted
- No
- Data monitoring committee
- No
Publications
Mills NL, Tornqvist H, Robinson SD, Gonzalez M, Darnley K, MacNee W, Boon NA, Donaldson K, Blomberg A, Sandstrom T, Newby DE. Diesel exhaust inhalation causes vascular dysfunction and impaired endogenous fibrinolysis. Circulation. 2005 Dec 20;112(25):3930-6. doi: 10.1161/CIRCULATIONAHA.105.588962.
PubMed 16365212Langrish JP, Unosson J, Bosson J, Barath S, Muala A, Blackwell S, Soderberg S, Pourazar J, Megson IL, Treweeke A, Sandstrom T, Newby DE, Blomberg A, Mills NL. Altered nitric oxide bioavailability contributes to diesel exhaust inhalation-induced cardiovascular dysfunction in man. J Am Heart Assoc. 2013 Feb 19;2(1):e004309. doi: 10.1161/JAHA.112.004309.
PubMed 23525434
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2009. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Cardiovascular Effects of Air Pollution: the Role of Nitric Oxide
- ClinicalTrials.gov ID
- NCT00845767
- Acronym / sponsor ID
- DNR 08-185M/1
- Conditions
- Endothelial Dysfunction
- Keywords
- Nitric Oxide, Nitric Oxide Synthase, Air Pollution, Endothelial Dysfunction, Diesel Exhaust
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (estimated)
- Lead sponsor
- University of EdinburghUniversity, hospital or other
- Collaborators
- Umeå University
- Study start
- Apr 2009
- Primary completion
- Jul 2009 (actual)
- Study completion
- Jul 2009 (actual)
- First posted
- 18 Feb 2009 (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.
Exposure to air pollution has been linked to increased cardiorespiratory morbidity and mortality. The exact component of air pollution that mediates this effect is unknown, but the link is strongest for fine combustion derived particulate matter derived from traffic sources. Recently, it has been demonstrated that inhalation of diesel exhaust impairs vascular vasomotor tone and endogenous fibrinolysis. The mechanism underlying these detrimental vascular is unclear, but is thought to be via oxidative stress and altered bioavailability of endogenous nitric oxide. In these studies we plan to elucidate the role of endogenous nitric oxide (NO) in the adverse vascular responses observed following exposure to diesel exhaust.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Diesel Exposure | Experimental | Procedure: Forearm Vascular Study1 hour exposure to dilute diesel exhaust at a concentration of 300 µg/m3 with intermittent exercise |
| Air Exposure | Experimental | Procedure: Forearm Vascular Study1 hour exposure to filtered air during intermittent exercise |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Healthy volunteers
Key exclusion criteria (4 listed)
- Use of regular medication (except oral contraceptive pill)
- Current smokers
- Significant occupational exposure to air pollution
- Intercurrent illness
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 |
|---|---|---|
| Forearm Vascular StudyAlso: ACh, SNP, BKForearm venous occlusion plethysmography during intraarterial infusion of L-NMMA (2-8 µmol/min) followed by co-infusion of sodium nitroprusside (90-900 ng/min) as a "nitric oxide clamp". Forearm blood flow then measured during the clamp in response to infused vasodilators acetylcholine (5-20 mg/min), bradykinin (100-1000 pmol/min), verapamil (10-100 µg/min) and sodium nitroprusside (2-8 µg/min). | Procedure or surgery | Air Exposure, Diesel Exposure |
Primary outcome
Forearm blood flow as measured by venous occlusion plethysmography during infusion of NOS inhibitors and vasodilators
Time frame: 2-4 hours after exposure
2 secondary outcomes
Plasma nitrite concentrations
Time frame: During forearm study
Plasma concentrations of t-PA and PAI
Time frame: After infusion of bradykinin during forearm study
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 9 Oct 2009.
- Background: PubMed 16365212Mills NL, Tornqvist H, Robinson SD, Gonzalez M, Darnley K, MacNee W, Boon NA, Donaldson K, Blomberg A, Sandstrom T, Newby DE. Diesel exhaust inhalation causes vascular dysfunction and impaired endogenous fibrinolysis. Circulation. 2005 Dec 20;112(25):3930-6. doi: 10.1161/CIRCULATIONAHA.105.588962.
- Derived from this study: PubMed 23525434Langrish JP, Unosson J, Bosson J, Barath S, Muala A, Blackwell S, Soderberg S, Pourazar J, Megson IL, Treweeke A, Sandstrom T, Newby DE, Blomberg A, Mills NL. Altered nitric oxide bioavailability contributes to diesel exhaust inhalation-induced cardiovascular dysfunction in man. J Am Heart Assoc. 2013 Feb 19;2(1):e004309. doi: 10.1161/JAHA.112.004309.
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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.
Anders Blomberg, MD PhD principal investigator
Umeå University
David E Newby, PhD FRCP principal investigator
University of Edinburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Forearm Vascular Study in people with Endothelial Dysfunction, run by University of Edinburgh at 1 site in Sweden.
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 4 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 9 Oct 2009. 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 Sweden. 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. 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?
Forearm blood flow as measured by venous occlusion plethysmography during infusion of NOS inhibitors and vasodilators (time frame: 2-4 hours after exposure). 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 NCT00845767, which also lists 2 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 9 Oct 2009.