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Effect of Woodsmoke on Vascular Function (FIREWOOD)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT01495325
Recruitment Status : Completed
First Posted : December 20, 2011
Last Update Posted : June 21, 2021
Sponsor:
Collaborators:
Umeå University
NHS Lothian
Information provided by (Responsible Party):
University of Edinburgh

Study Description
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Brief 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. 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 or disease Intervention/treatment Phase
Vascular Function Procedure: Forearm Vascular Study Procedure: Badimon Chamber Not Applicable

Study Design
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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 16 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Effect of Woodsmoke on Vascular Function in Healthy Firefighters
Actual Study Start Date : September 2011
Actual Primary Completion Date : August 2014
Actual Study Completion Date : August 2014
Arms and Interventions
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Arm Intervention/treatment
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:
  • Other Names:
  • BK
  • SNP
  • ACh

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:
  • Other Names:
  • BK
  • SNP
  • ACh

Procedure: Badimon Chamber
Ex-vivo assessment of thrombus formation using the Badimon Chamber


Outcome Measures
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Primary Outcome Measures :
  1. Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators [ Time Frame: 4-6 hours after exposure ]

Secondary Outcome Measures :
  1. Ex-vivo thrombus formation using the Badimon chamber [ Time Frame: 2 hours after exposure ]
  2. Plasma t-PA and PAI concentrations following infusion of bradykinin [ Time Frame: During forearm study, 4-6hours after exposure ]

Eligibility Criteria
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Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

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
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Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01495325


Locations
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Sweden
Umeå University
Umeå, Västerbotten, Sweden, SE-901 85
Sponsors and Collaborators
University of Edinburgh
Umeå University
NHS Lothian
Investigators
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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
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Publications of Results:

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

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Responsible Party: University of Edinburgh
ClinicalTrials.gov Identifier: NCT01495325    
Other Study ID Numbers: 2011-194-31M
PG/11/27/28842 ( Other Grant/Funding Number: BRITISH HEART FOUNDATION )
First Posted: December 20, 2011    Key Record Dates
Last Update Posted: June 21, 2021
Last Verified: June 2021
Keywords provided by University of Edinburgh:
Firefighter
Woodsmoke
Vascular function
 Air Pollution
Endothelial function
Thrombosis