Effect of Woodsmoke on Vascular Function (FIREWOOD)

This study is currently recruiting participants. (see Contacts and Locations)
Verified January 2013 by University of Edinburgh
Sponsor:
Collaborators:
Umeå University
NHS Lothian
Information provided by (Responsible Party):
University of Edinburgh
ClinicalTrials.gov Identifier:
NCT01495325
First received: October 11, 2011
Last updated: January 23, 2013
Last verified: January 2013
  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

Resource links provided by NLM:


Further study details as provided by University of Edinburgh:

Primary Outcome Measures:
  • 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 ]

Secondary Outcome Measures:
  • 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:
  • 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

  Eligibility

Ages Eligible for Study:   18 Years to 35 Years
Genders 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
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01495325

Contacts
Contact: Amanda L Hunter, MBChB +441312426437 amanda.hunter@ed.ac.uk
Contact: Jenny Bosson, MD PhD jenny.bosson@gmail.com

Locations
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         
Sponsors and Collaborators
University of Edinburgh
Umeå University
NHS Lothian
Investigators
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 July 29, 2014