Effect of Woodsmoke on Vascular Function (FIREWOOD)
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Purpose
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.
| Condition | Intervention |
|---|---|
|
Vascular Function |
Procedure: Forearm Vascular Study Procedure: Badimon Chamber |
| Study Type: | Interventional |
| Study Design: | Allocation: Randomized Intervention Model: Crossover Assignment Masking: Double Blind (Subject, Investigator, Outcomes Assessor) Primary Purpose: Basic Science |
| Official Title: | Effect of Woodsmoke on Vascular Function in Healthy Firefighters |
- Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators [ Time Frame: 4-6 hours after exposure ] [ Designated as safety issue: No ]
- Ex-vivo thrombus formation using the Badimon chamber [ Time Frame: 2 hours after exposure ] [ Designated as safety issue: No ]
- Plasma t-PA and PAI concentrations following infusion of bradykinin [ Time Frame: During forearm study, 4-6hours after exposure ] [ Designated as safety issue: No ]
| Estimated Enrollment: | 20 |
| Study Start Date: | September 2011 |
| Estimated Study Completion Date: | January 2013 |
| Estimated Primary Completion Date: | January 2013 (Final data collection date for primary outcome measure) |
| Arms | Assigned Interventions |
|---|---|
|
Sham Comparator: Filtered Air Exposure
1 hour exposure to filtered air during intermittent exercise
|
Procedure: Forearm Vascular Study
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).
Other Names:
Procedure: Badimon Chamber
Ex-vivo assessment of thrombus formation using the Badimon Chamber
|
|
Active Comparator: Woodsmoke Exposure
1 hour exposure to dilute woodsmoke at a concentration of 1000µg/m3 during intermittent exercise
|
Procedure: Forearm Vascular Study
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).
Other Names:
Procedure: Badimon Chamber
Ex-vivo assessment of thrombus formation using the Badimon Chamber
|
Eligibility| Ages Eligible for Study: | 18 Years to 35 Years |
| Genders Eligible for Study: | Male |
| Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Non-smoking healthy male firefighters or volunteers
Exclusion Criteria:
- 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
- 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
Contacts and Locations| Contact: Amanda L Hunter, MBChB | +441312426437 | amanda.hunter@ed.ac.uk |
| Contact: Jenny Bosson, MD PhD | jenny.bosson@gmail.com |
| Sweden | |
| Umeå University | Recruiting |
| Umeå, Västerbotten, Sweden, SE-901 85 | |
| Principal Investigator: Amanda L Hunter, MBChB | |
| Sub-Investigator: Jenny Bosson, MD PhD | |
| Sub-Investigator: Jon Unosson, MD | |
| Study Director: | Nicholas L Mills, MBChB PhD | University of Edinburgh |
| Study Chair: | David E Newby, MD PhD | University of Edinburgh |
| Study Director: | Anders Blomberg, MD PhD | Umeå University |
| Study Director: | Thomas Sandström, MD PhD | Umeå Univerisity |
| Principal Investigator: | Amanda L Hunter, MBChB | University of Edinburgh |
More Information
No publications provided
| Responsible Party: | University of Edinburgh |
| ClinicalTrials.gov Identifier: | NCT01495325 History of Changes |
| Other Study ID Numbers: | 2011-194-31M, PG/11/27/28842 |
| Study First Received: | October 11, 2011 |
| Last Updated: | January 23, 2013 |
| Health Authority: | Sweden: Regional Ethical Review Board |
Keywords provided by University of Edinburgh:
|
Firefighter Woodsmoke Vascular function |
Air Pollution Endothelial function Thrombosis |
ClinicalTrials.gov processed this record on May 19, 2013