Effect of Woodsmoke on Vascular Function (FIREWOOD)

June 17, 2021 updated by: University of Edinburgh

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

16

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Sweden
    • Västerbotten
      • Umeå, Västerbotten, Sweden, SE-901 85
        • Umeå University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 35 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators
Time Frame: 4-6 hours after exposure
4-6 hours after exposure

Secondary Outcome Measures

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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Edinburgh

Collaborators

Umeå University
NHS Lothian

Investigators

  • Study Chair: David E Newby, MD PhD, University of Edinburgh
  • Study Director: Nicholas L Mills, MBChB PhD, University of Edinburgh
  • Principal Investigator: Amanda L Hunter, MBChB, University of Edinburgh
  • Study Director: Anders Blomberg, MD PhD, Umeå University
  • Study Director: Thomas Sandström, MD PhD, Umeå Univerisity

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2011

Primary Completion (Actual)

August 1, 2014

Study Completion (Actual)

August 1, 2014

Study Registration Dates

First Submitted

October 11, 2011

First Submitted That Met QC Criteria

December 15, 2011

First Posted (Estimate)

December 20, 2011

Study Record Updates

Last Update Posted (Actual)

June 21, 2021

Last Update Submitted That Met QC Criteria

June 17, 2021

Last Verified

June 1, 2021

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 2011-194-31M
  • PG/11/27/28842 (Other Grant/Funding Number: British Heart Foundation)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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