Effect of Woodsmoke on Vascular Function

NCT01495325 | Completed DMC

• 2 other identifiers: 2011-194-31MPG/11/27/28842
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

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.

Conditions

Vascular Function

Keywords

Firefighter; Woodsmoke; Vascular function; Air Pollution; Endothelial function; Thrombosis

Outcome Measures

Primary Outcomes (1)

• Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators

  4-6 hours after exposure

Secondary Outcomes (2)

• Ex-vivo thrombus formation using the Badimon chamber

  2 hours after exposure

• Plasma t-PA and PAI concentrations following infusion of bradykinin

  During forearm study, 4-6hours after exposure

Study Arms (2)

Filtered Air Exposure

SHAM COMPARATOR

1 hour exposure to filtered air during intermittent exercise

Procedure: Forearm Vascular Study; Procedure: Badimon Chamber

Woodsmoke Exposure

ACTIVE COMPARATOR

1 hour exposure to dilute woodsmoke at a concentration of 1000µg/m3 during intermittent exercise

Procedure: Forearm Vascular Study; Procedure: Badimon Chamber

Interventions

Forearm Vascular Study PROCEDURE

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).

Also known as: Other Names:, BK, SNP, ACh

Filtered Air Exposure; Woodsmoke Exposure

Badimon Chamber PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Filtered Air Exposure; Woodsmoke Exposure

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Non-smoking healthy male firefighters or volunteers

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Edinburgh: lead
• Umeå University: collaborator
• NHS Lothian: collaborator

Study Sites (1)

Umeå University

Umeå, Västerbotten County, SE-901 85, Sweden

Location

Related Publications (2)

• Hunter AL, Unosson J, Bosson JA, Langrish JP, Pourazar J, Raftis JB, Miller MR, Lucking AJ, Boman C, Nystrom R, Donaldson K, Flapan AD, Shah AS, Pung L, Sadiktsis I, Masala S, Westerholm R, Sandstrom T, Blomberg A, Newby DE, Mills NL. Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters. Part Fibre Toxicol. 2014 Dec 9;11:62. doi: 10.1186/s12989-014-0062-4.

  PMID: 25487196 RESULT

• Langrish JP, Watts SJ, Hunter AJ, Shah AS, Bosson JA, Unosson J, Barath S, Lundback M, Cassee FR, Donaldson K, Sandstrom T, Blomberg A, Newby DE, Mills NL. Controlled exposures to air pollutants and risk of cardiac arrhythmia. Environ Health Perspect. 2014 Jul;122(7):747-53. doi: 10.1289/ehp.1307337. Epub 2014 Mar 25.

  PMID: 24667535 DERIVED

MeSH Terms

Conditions

Thrombosis

Condition Hierarchy (Ancestors)

Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases

Study Officials

• Nicholas L Mills, MBChB PhD

  University of Edinburgh

  STUDY DIRECTOR

• David E Newby, MD PhD

  University of Edinburgh

  STUDY CHAIR

• Anders Blomberg, MD PhD

  Umeå University

  STUDY DIRECTOR

• Thomas Sandström, MD PhD

  Umeå Univerisity

  STUDY DIRECTOR

• Amanda L Hunter, MBChB

  University of Edinburgh

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 11, 2011
• First Posted: December 20, 2011
• Study Start: September 1, 2011
• Primary Completion: August 1, 2014
• Study Completion: August 1, 2014
• Last Updated: June 21, 2021

Record last verified: 2021-06

Locations

SE (1)