Effect of Woodsmoke on Vascular Function

Vascular Function Clinical Trial

— FIREWOOD  

Official title:

Effect of Woodsmoke on Vascular Function in Healthy Firefighters

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01495325
• Other study ID #: 2011-194-31M
• Secondary ID: PG/11/27/28842
• Status: Completed
• Phase: N/A
• Start date: September 2011
• Est. completion date: August 2014

Study information

• Verified date: June 2021
• Source: University of Edinburgh
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical 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. 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 16
• Est. completion date: August 2014
• Est. primary completion date: August 2014
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 35 Years

Eligibility

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

Related Conditions & MeSH terms

• Vascular Function

Intervention

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).
• Badimon Chamber
Ex-vivo assessment of thrombus formation using the Badimon Chamber

Locations

Country	Name	City	State
Sweden	Umeå University	Umeå	Västerbotten

Sponsors (3)

Lead Sponsor	Collaborator
University of Edinburgh	NHS Lothian, Umeå University

Country where clinical trial is conducted

Sweden, 

References & Publications (1)

Hunter AL, Unosson J, Bosson JA, Langrish JP, Pourazar J, Raftis JB, Miller MR, Lucking AJ, Boman C, Nyström R, Donaldson K, Flapan AD, Shah AS, Pung L, Sadiktsis I, Masala S, Westerholm R, Sandström T, Blomberg A, Newby DE, Mills NL. Effect of wood smoke — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators		4-6 hours after exposure
Secondary	Ex-vivo thrombus formation using the Badimon chamber		2 hours after exposure
Secondary	Plasma t-PA and PAI concentrations following infusion of bradykinin		During forearm study, 4-6hours after exposure