Effect of Woodsmoke on Vascular Function

NCT ID: NCT01495325

Last Updated: 2021-06-21

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 16 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2011-09-30
• Study Completion Date: 2014-08-31

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

Filtered Air Exposure

1 hour exposure to filtered air during intermittent exercise

Group Type: SHAM_COMPARATOR

Forearm Vascular Study

Intervention Type: 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).

Badimon Chamber

Intervention Type: PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Woodsmoke Exposure

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

Group Type: ACTIVE_COMPARATOR

Forearm Vascular Study

Intervention Type: 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).

Badimon Chamber

Intervention Type: PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Interventions

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).

Intervention Type: PROCEDURE

Badimon Chamber

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Intervention Type: PROCEDURE

Other Intervention Names

Other Names: BK; SNP; ACh

Eligibility 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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Umeå University

OTHER

Sponsor Role: collaborator

NHS Lothian

OTHER_GOV

Sponsor Role: collaborator

University of Edinburgh

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Nicholas L Mills, MBChB PhD

Role: STUDY_DIRECTOR

University of Edinburgh

David E Newby, MD PhD

Role: STUDY_CHAIR

University of Edinburgh

Anders Blomberg, MD PhD

Role: STUDY_DIRECTOR

Umeå University

Thomas Sandström, MD PhD

Role: STUDY_DIRECTOR

Umeå Univerisity

Amanda L Hunter, MBChB

Role: PRINCIPAL_INVESTIGATOR

University of Edinburgh

Locations

Umeå University

Umeå, Västerbotten County, Sweden

Countries

Sweden

References

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.

Reference Type: RESULT

PMID: 25487196 (View on PubMed)

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.

Reference Type: DERIVED

PMID: 24667535 (View on PubMed)

Other Identifiers

PG/11/27/28842

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

2011-194-31M

Identifier Type: -

Identifier Source: org_study_id