Diesel Exhaust and Vascular Function (CVDTRAP4)

This study is currently recruiting participants. (see Contacts and Locations)
Verified June 2012 by University of Washington
Sponsor:
Collaborators:
Information provided by (Responsible Party):
Joel Daniel Kaufman, University of Washington
ClinicalTrials.gov Identifier:
NCT01508637
First received: January 5, 2012
Last updated: June 12, 2012
Last verified: June 2012
  Purpose

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.


Condition Intervention
Cardiovascular Effects
Other: Diesel Exhaust
Other: Filtered Air
Drug: Terazosin
Drug: placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Effect of Diesel Exhaust Exposures on Vascular Function in Humans: The Role of Sympathetic Activation

Resource links provided by NLM:


Further study details as provided by University of Washington:

Primary Outcome Measures:
  • Systolic Blood Pressure [ Time Frame: 30-90 minutes after exposure initiation ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Brachial artery diameter [ Time Frame: Assessed 30 minutes prior to exposure and 30 minutes post-exposure ] [ Designated as safety issue: No ]
    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.


Estimated Enrollment: 24
Study Start Date: January 2012
Estimated Study Completion Date: December 2014
Estimated Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Diesel Exhaust + Terazosin Other: Diesel Exhaust
Freshly generated diesel exhaust, diluted to 300 micrograms/cubic meter. Exposures are two hours in duration.
Drug: Terazosin
2 mg by mouth, 90 minutes prior to exposure initiation
Experimental: Diesel Exhaust + placebo Other: Diesel Exhaust
Freshly generated diesel exhaust, diluted to 300 micrograms/cubic meter. Exposures are two hours in duration.
Drug: placebo
capsule, identical in appearance to terazosin capsule, by mouth, 30 minutes prior to exposure initiation
Sham Comparator: Filtered Air + terazosin 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
Sham Comparator: Filtered air + placebo 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: placebo
capsule, identical in appearance to terazosin capsule, by mouth, 30 minutes prior to exposure initiation

  Eligibility

Ages Eligible for Study:   18 Years to 49 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01508637

Contacts
Contact: Karen Jansen, M.S. 206-616-6525 cvd1trap@uw.edu

Locations
United States, Washington
University of Washington Medical Center Recruiting
Seattle, Washington, United States, 98195
Sponsors and Collaborators
University of Washington
Investigators
Principal Investigator: Joel D Kaufman, MD, MPH University of Washington
  More Information

No publications provided

Responsible Party: Joel Daniel Kaufman, Professor, University of Washington
ClinicalTrials.gov Identifier: NCT01508637     History of Changes
Other Study ID Numbers: 39833-D, P50ES015915
Study First Received: January 5, 2012
Last Updated: June 12, 2012
Health Authority: United States: Institutional Review Board
United States: Federal Government

Keywords provided by University of Washington:
air pollution
vasoconstriction
blood pressure
diesel exhaust

Additional relevant MeSH terms:
Terazosin
Adrenergic alpha-1 Receptor Antagonists
Adrenergic alpha-Antagonists
Adrenergic Antagonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Physiological Effects of Drugs
Urological Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on September 29, 2014