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The Cardiovascular Effects of Nitrogen Dioxide Exposure

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ClinicalTrials.gov Identifier: NCT00774514
Recruitment Status : Completed
First Posted : October 17, 2008
Last Update Posted : April 9, 2009
Sponsor:
Collaborator:
Umeå University
Information provided by:
University of Edinburgh

Study Description
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Brief Summary:
Exposure to air pollution has been linked to increased cardiorespiratory morbidity and mortality. The exact component of air pollution that mediates this effect is unknown, but the link is strongest for fine combustion derived particulate matter derived from traffic sources. It has been demonstrated that inhalation of diesel exhaust impairs vascular vasomotor tone and endogenous fibrinolysis. Recent studies using an inline retrofit particle trap to reduce the particulate component of exhaust have shown that filtering particles leads to a reversal of the endothelial dysfunction seen after diesel exhaust exposure, and have even suggested an augmentation of vascular function. This raises the question of the cardiovascular effects of the gaseous pollutants, the most abundant of which is nitrogen dioxide. In this study we plan to investigate the cardiovascular effects of nitrogen dioxide exposure.

Condition or disease Intervention/treatment Phase
Endothelial Dysfunction Procedure: Forearm Vascular Study Not Applicable

Study Design
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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 12 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: The Cardiovascular Effects of Nitrogen Dioxide Exposure
Study Start Date : October 2008
Actual Primary Completion Date : December 2008
Actual Study Completion Date : December 2008
Arms and Interventions
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Arm Intervention/treatment
Experimental: 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 intrabrachial infusion of vasodilators Acetylcholine (5-20 mg/min), sodium nitroprusside (2-8 µg/min), bradykinin (100-1000 pmol/min) and verapamil (10-100 µg/min)
Other Names:
  • ACh
  • SNP
  • BK
Experimental: NO2 exposure
1 hour exposure to nitrogen dioxide at 4ppm during intermittent exercise
 Procedure: Forearm Vascular Study
Forearm venous occlusion plethysmography to measure forearm blood flow during intrabrachial infusion of vasodilators Acetylcholine (5-20 mg/min), sodium nitroprusside (2-8 µg/min), bradykinin (100-1000 pmol/min) and verapamil (10-100 µg/min)
Other Names:
  • ACh
  • SNP
  • BK


Outcome Measures
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Primary Outcome Measures :
  1. Forearm blood flow measured by venous occlusion plethysmography in response to intraarterial vasodilators (acetylcholine, sodium nitroprusside, bradykinin and verapamil) [ Time Frame: 4-6 hours after exposure ]

Secondary Outcome Measures :
  1. Plasma t-PA concentrations after infusion of bradykinin [ Time Frame: During forearm study ]
  2. Exhaled nitric oxide [ Time Frame: 4-6 hours after exposure ]

Eligibility Criteria
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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Healthy male volunteers

Exclusion Criteria:

  • Current smokers
  • Significant occupational exposure to air pollution
  • Regular medication use
  • Intercurrent illness
Contacts and Locations
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Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00774514


Locations
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Sweden
Umeå University
Umeå, Sweden
Sponsors and Collaborators
University of Edinburgh
Umeå University
Investigators
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Principal Investigator: Thomas Sandström, MD PhD Umeå University
Principal Investigator: Anders Blomberg, MD PhD Umeå University
More Information
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Responsible Party: Dr Anders Blomberg, Umeå University
ClinicalTrials.gov Identifier: NCT00774514    
Other Study ID Numbers: Dnr 08-113M
First Posted: October 17, 2008    Key Record Dates
Last Update Posted: April 9, 2009
Last Verified: April 2009
Keywords provided by University of Edinburgh:
Air Pollution
Nitrogen Dioxide
NO2
Endothelial dysfunction