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Diesel Exhaust and Vascular Function (CVDTRAP4)

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ClinicalTrials.gov Identifier: NCT01508637
Recruitment Status : Unknown
Verified July 2015 by Joel Daniel Kaufman, University of Washington.
Recruitment status was:  Recruiting
First Posted : January 12, 2012
Last Update Posted : August 3, 2015
Information provided by (Responsible Party):

January 5, 2012
January 12, 2012
August 3, 2015
January 2012
December 2015   (Final data collection date for primary outcome measure)
Systolic Blood Pressure [ Time Frame: 30-90 minutes after exposure initiation ]
Same as current
Complete list of historical versions of study NCT01508637 on ClinicalTrials.gov Archive Site
Brachial artery diameter [ Time Frame: Assessed 30 minutes prior to exposure and 30 minutes post-exposure ]
The investigators anticipate vasoconstriction (post-exposure vs. pre-exposure) as observed in this conduit artery in response to exposure to Diesel Exhaust, compared to Filtered Air sham exposure.
Same as current
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Diesel Exhaust and Vascular Function
Effect of Diesel Exhaust Exposures on Vascular Function in Humans: The Role of Sympathetic Activation
Double-blind, sham- and placebo-controlled randomized study of effects of freshly-generated diluted diesel exhaust inhalation on vascular function. To examine role of adrenergic system a trial of alpha-blocker terazosin is also used. Each participant completes four study sessions, separated by at least three weeks: 1) Diesel exhaust inhalation (DE, controlled at 300 micrograms/cubic meter for two hours) and terazosin (2 mg prior to inhalation exposure); 2) DE plus placebo (matched for terazosin); 3) filtered air plus terazosin; and 4) filter air plus placebo. The investigators assess outcomes of blood pressure, forearm brachial artery ultrasound, and plasma measures of endothelial activation. The investigators hypothesize that DE exposure will be associated with increased blood pressure, decreased brachial artery diameter, and increased circulating endothelins, and that these effects will be attenuated by terazosin administration.
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Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Cardiovascular Effects
  • Other: Diesel Exhaust
    Freshly generated diesel exhaust, diluted to 300 micrograms/cubic meter. Exposures are two hours in duration.
  • Other: Filtered Air
    Sham exposure, identical to conditions of diesel exhaust exposure, but with only air filtered of particles and volatile organic compound gases
  • Drug: Terazosin
    2 mg by mouth, 90 minutes prior to exposure initiation
  • Drug: placebo
    capsule, identical in appearance to terazosin capsule, by mouth, 30 minutes prior to exposure initiation
  • Experimental: Diesel Exhaust + Terazosin
    • Other: Diesel Exhaust
    • Drug: Terazosin
  • Experimental: Diesel Exhaust + placebo
    • Other: Diesel Exhaust
    • Drug: placebo
  • Sham Comparator: Filtered Air + terazosin
    • Other: Filtered Air
    • Drug: Terazosin
  • Sham Comparator: Filtered air + placebo
    • Other: Filtered Air
    • Drug: placebo
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
Unknown status
December 2015
December 2015   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • healthy without chronic illness
  • Body Mass Index 18.5 - 26.0
  • tolerates 2 mg terazosin dose without unacceptable symptoms
  • able to return for four exposure sessions

Exclusion Criteria:

  • any chronic disease
  • tobacco user
  • asthma
  • elevated cholesterol
  • obesity
  • hypertension
  • diabetes
  • any chronic cardiovascular or pulmonary disease
  • pregnancy or unwillingness to use effective contraception, if female
Sexes Eligible for Study: All
18 Years to 49 Years   (Adult)
Contact information is only displayed when the study is recruiting subjects
United States
P50ES015915 ( U.S. NIH Grant/Contract )
Not Provided
Not Provided
Joel Daniel Kaufman, University of Washington
University of Washington
  • National Institute of Environmental Health Sciences (NIEHS)
  • Environmental Protection Agency (EPA)
Principal Investigator: Joel D Kaufman, MD, MPH University of Washington
University of Washington
July 2015

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP