Vascular FunctionFIREWOODNCT01495325
Effect of Woodsmoke on Vascular Function
A study testing Forearm Vascular Study and Badimon Chamber in people with Vascular Function, run by University of Edinburgh at 1 site in Sweden.
Trial summary
Exposure to air pollution is a well established risk factor for the development of heart disease. Firefighters are exposed to excess air pollution in the form of wood smoke during the extinguishing of forest or woodland fires. Read more about this study
- Who is it for?
- Ages 18 to 35 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Vascular Function
- What is being tested?
- Forearm Vascular Study and Badimon Chamber
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 16 participants
- Where
- 1 siteSweden
- Study dates
- Sep 2011to Aug 2014
- 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 35 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Non-smoking healthy male firefighters or volunteers
Who cannot join
- Current smoker or regular users of snus
- History of lung or ischaemic heart disease
- Malignant arrhythmia
- Systolic blood pressure >190mmHg or <100mmHg
- Renal or hepatic dysfunction
- Previous history of blood dyscrasia
Show all 10Show fewer
- Unable to tolerate the supine position
- Blood donation within the last 3 months
- Recent respiratory tract infection within the past 4 weeks
- Routine medication including aspirin and NSAIDs
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of Woodsmoke on Vascular Function in Healthy Firefighters
Exposure to air pollution is a well established risk factor for the development of heart disease. Firefighters are exposed to excess air pollution in the form of wood smoke during the extinguishing of forest or woodland fires. Heart attacks in on-duty firefighters have been linked to specific duties and in particular fire suppression, but the reasons for this increase in risk are not well understood. Exposure to wood smoke may alter blood vessel function and increase blood clot formation to explain the link between fire suppression and heart attacks.
The investigators wish to determine the effect of exposure to wood smoke at concentrations found at the perimeter of a woodland fire on blood vessel function and clotting in healthy non-smoking male professional firefighters or volunteers. Volunteers will be studied before and after inhalation of wood smoke or clean air for one hour in a purpose built whole-body exposure chamber. The investigators will perform comprehensive vascular assessments thereafter.
Understanding the effects of wood smoke on the blood vessels and clotting will be an important first step in helping to protect firefighters from heart disease. Through research, the investigators hope to identify methods to minimise the risk of heart attacks in firefighters and understand the health effects of a major source of air pollution that is relevant to the general population.
- Conditions
- Vascular Function
- Being tested
- Forearm Vascular Study, Badimon Chamber
- Keywords
- Firefighter, Woodsmoke, Vascular function, Air Pollution, Endothelial function, Thrombosis
- Medical subject headings
- Thrombosis
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 Other Names:, BK, SNP, ACh
Forearm venous occlusion plethysmography to measure forearm blood flow during intra-arterial infusion of the vasodilators Verapamil (10-100 µg/min), bradykinin (100-1000 pmol/min), sodium nitroprusside (2-8 µg/min) and Acetylcholine (5-20 µg/min).
Badimon ChamberProcedure or surgery
Ex-vivo assessment of thrombus formation using the Badimon Chamber
| Study group | Role | What they receive |
|---|---|---|
| Filtered Air Exposure | Sham comparator | 1 hour exposure to filtered air during intermittent exercise Receives: Procedure: Forearm Vascular Study; Procedure: Badimon Chamber |
| Woodsmoke Exposure | Active comparator | 1 hour exposure to dilute woodsmoke at a concentration of 1000µg/m3 during intermittent exercise Receives: Procedure: Forearm Vascular Study; Procedure: Badimon Chamber |
What is being measured
The primary outcome is the main question the study is designed to answer.
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators
Measured: 4-6 hours after exposure
Secondary outcomes (2)
Ex-vivo thrombus formation using the Badimon chamber
Measured: 2 hours after exposure
Plasma t-PA and PAI concentrations following infusion of bradykinin
Measured: During forearm study, 4-6hours after exposure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Dec 2011 (estimated)
- Study startSep 2011
- Primary completionAug 2014
- Study completionAug 2014
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 Vascular FunctionStudies of the same condition, open and under way.
- 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 (actual)
Sponsor and investigators
- Lead sponsor
- University of Edinburgh
- Sponsor type
- University, hospital or other
- Collaborators
- Umeå University, NHS Lothian
- Responsible party
- Sponsor
- Investigators
- Nicholas L Mills, MBChB PhD, Study director, University of EdinburghDavid E Newby, MD PhD, Study chair, University of EdinburghAnders Blomberg, MD PhD, Study director, Umeå UniversityThomas Sandström, MD PhD, Study director, Umeå UniverisityAmanda L Hunter, MBChB, Principal investigator, University of Edinburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01495325
- Sponsor's protocol ID
- 2011-194-31M
- Other IDs
- PG/11/27/28842
- Acronym
- FIREWOOD
- Status last verified
- Jun 2021
- First submitted
- 11 Oct 2011
- Last updated
- 21 Jun 2021
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Hunter AL, Unosson J, Bosson JA, Langrish JP, Pourazar J, Raftis JB, Miller MR, Lucking AJ, Boman C, Nystrom R, Donaldson K, Flapan AD, Shah AS, Pung L, Sadiktsis I, Masala S, Westerholm R, Sandstrom T, Blomberg A, Newby DE, Mills NL. Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters. Part Fibre Toxicol. 2014 Dec 9;11:62. doi: 10.1186/s12989-014-0062-4.
PubMed 25487196Langrish JP, Watts SJ, Hunter AJ, Shah AS, Bosson JA, Unosson J, Barath S, Lundback M, Cassee FR, Donaldson K, Sandstrom T, Blomberg A, Newby DE, Mills NL. Controlled exposures to air pollutants and risk of cardiac arrhythmia. Environ Health Perspect. 2014 Jul;122(7):747-53. doi: 10.1289/ehp.1307337. Epub 2014 Mar 25.
PubMed 24667535
Study at a glance
From the registry record, last updated by the sponsor on 21 Jun 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Woodsmoke on Vascular Function in Healthy Firefighters
- ClinicalTrials.gov ID
- NCT01495325
- Acronym / sponsor ID
- FIREWOOD / 2011-194-31M
- Conditions
- Vascular Function
- Keywords
- Firefighter, Woodsmoke, Vascular function, Air Pollution, Endothelial function, Thrombosis
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- University of EdinburghUniversity, hospital or other
- Collaborators
- Umeå University, NHS Lothian
- Study start
- Sep 2011 (actual)
- Primary completion
- Aug 2014 (actual)
- Study completion
- Aug 2014 (actual)
- First posted
- 20 Dec 2011 (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 is a well established risk factor for the development of heart disease. Firefighters are exposed to excess air pollution in the form of wood smoke during the extinguishing of forest or woodland fires. Heart attacks in on-duty firefighters have been linked to specific duties and in particular fire suppression, but the reasons for this increase in risk are not well understood. Exposure to wood smoke may alter blood vessel function and increase blood clot formation to explain the link between fire suppression and heart attacks.
The investigators wish to determine the effect of exposure to wood smoke at concentrations found at the perimeter of a woodland fire on blood vessel function and clotting in healthy non-smoking male professional firefighters or volunteers. Volunteers will be studied before and after inhalation of wood smoke or clean air for one hour in a purpose built whole-body exposure chamber. The investigators will perform comprehensive vascular assessments thereafter.
Understanding the effects of wood smoke on the blood vessels and clotting will be an important first step in helping to protect firefighters from heart disease. Through research, the investigators hope to identify methods to minimise the risk of heart attacks in firefighters and understand the health effects of a major source of air pollution that is relevant to the general population.
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 |
|---|---|---|
| Filtered Air Exposure | Sham comparator | Procedure: Forearm Vascular Study, Procedure: Badimon Chamber1 hour exposure to filtered air during intermittent exercise |
| Woodsmoke Exposure | Active comparator | Procedure: Forearm Vascular Study, Procedure: Badimon Chamber1 hour exposure to dilute woodsmoke at a concentration of 1000µg/m3 during intermittent exercise |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Non-smoking healthy male firefighters or volunteers
Key exclusion criteria (10 listed)
- Current smoker or regular users of snus
- History of lung or ischaemic heart disease
- Malignant arrhythmia
- Systolic blood pressure >190mmHg or <100mmHg
- Renal or hepatic dysfunction
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: Other Names:, BK, SNP, AChForearm venous occlusion plethysmography to measure forearm blood flow during intra-arterial infusion of the vasodilators Verapamil (10-100 µg/min), bradykinin (100-1000 pmol/min), sodium nitroprusside (2-8 µg/min) and Acetylcholine (5-20 µg/min). | Procedure or surgery | Filtered Air Exposure, Woodsmoke Exposure |
| Badimon ChamberEx-vivo assessment of thrombus formation using the Badimon Chamber | Procedure or surgery | Filtered Air Exposure, Woodsmoke Exposure |
Primary outcome
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators
Time frame: 4-6 hours after exposure
2 secondary outcomes
Ex-vivo thrombus formation using the Badimon chamber
Time frame: 2 hours after exposure
Plasma t-PA and PAI concentrations following infusion of bradykinin
Time frame: During forearm study, 4-6hours after exposure
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 21 Jun 2021.
- Results publication: PubMed 25487196Hunter AL, Unosson J, Bosson JA, Langrish JP, Pourazar J, Raftis JB, Miller MR, Lucking AJ, Boman C, Nystrom R, Donaldson K, Flapan AD, Shah AS, Pung L, Sadiktsis I, Masala S, Westerholm R, Sandstrom T, Blomberg A, Newby DE, Mills NL. Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters. Part Fibre Toxicol. 2014 Dec 9;11:62. doi: 10.1186/s12989-014-0062-4.
- Derived from this study: PubMed 24667535Langrish JP, Watts SJ, Hunter AJ, Shah AS, Bosson JA, Unosson J, Barath S, Lundback M, Cassee FR, Donaldson K, Sandstrom T, Blomberg A, Newby DE, Mills NL. Controlled exposures to air pollutants and risk of cardiac arrhythmia. Environ Health Perspect. 2014 Jul;122(7):747-53. doi: 10.1289/ehp.1307337. Epub 2014 Mar 25.
Related trials for Vascular Function
Not yet recruiting
Closed-Loop SCS-BCI for Post-Stroke Hemiplegia
Stroke, Motor Dysfunction
Active, not recruitingPhase 1
A Phase 1b Study of BHV-7000 in Participants With Inherited Erythromelalgia
Familial Erythromelalgia
Not yet recruitingObservational study
Vascular Health and Function in Cystic Fibrosis
Cystic Fibrosis, Endothelial Dysfunction
Not yet recruiting
Effect of Early Tendon Vibrations on Upper Limb Motor Recovery After a Stroke
Acute Stroke, Upper Limb Motor Deficit
Recruiting
Hemodynamics After Resistance Training
Perimenopause
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.
Nicholas L Mills, MBChB PhD study director
University of Edinburgh
David E Newby, MD PhD study chair
University of Edinburgh
Anders Blomberg, MD PhD study director
Umeå University
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 and Badimon Chamber in people with Vascular Function, 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 10 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 21 Jun 2021. 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. 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?
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators (time frame: 4-6 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 NCT01495325, 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 21 Jun 2021.