Diesel Exhaust and Vascular Function (CVDTRAP4)
July 30, 2015 updated by: Joel Daniel Kaufman, University of Washington
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.
Study Overview
Status
Unknown
Conditions
Intervention / Treatment
Study Type
Interventional
Enrollment (Anticipated)
24
Phase
- Not Applicable
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Locations
-
-
Washington
-
Seattle, Washington, United States, 98195
- Recruiting
- University of Washington Medical Center
-
-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
18 years to 49 years (Adult)
Accepts Healthy Volunteers
Yes
Genders Eligible for Study
All
Description
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
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Crossover Assignment
- Masking: Triple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Experimental: Diesel Exhaust + Terazosin
|
Freshly generated diesel exhaust, diluted to 300 micrograms/cubic meter.
Exposures are two hours in duration.
2 mg by mouth, 90 minutes prior to exposure initiation
|
|
Experimental: Diesel Exhaust + placebo
|
Freshly generated diesel exhaust, diluted to 300 micrograms/cubic meter.
Exposures are two hours in duration.
capsule, identical in appearance to terazosin capsule, by mouth, 30 minutes prior to exposure initiation
|
|
Sham Comparator: Filtered Air + terazosin
|
2 mg by mouth, 90 minutes prior to exposure initiation
Sham exposure, identical to conditions of diesel exhaust exposure, but with only air filtered of particles and volatile organic compound gases
|
|
Sham Comparator: Filtered air + placebo
|
capsule, identical in appearance to terazosin capsule, by mouth, 30 minutes prior to exposure initiation
Sham exposure, identical to conditions of diesel exhaust exposure, but with only air filtered of particles and volatile organic compound gases
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Time Frame |
|---|---|
|
Systolic Blood Pressure
Time Frame: 30-90 minutes after exposure initiation
|
30-90 minutes after exposure initiation
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
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.
|
Assessed 30 minutes prior to exposure and 30 minutes post-exposure
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Collaborators
Investigators
- Principal Investigator: Joel D Kaufman, MD, MPH, University of Washington
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start
January 1, 2012
Primary Completion (Anticipated)
December 1, 2015
Study Completion (Anticipated)
December 1, 2015
Study Registration Dates
First Submitted
January 5, 2012
First Submitted That Met QC Criteria
January 11, 2012
First Posted (Estimate)
January 12, 2012
Study Record Updates
Last Update Posted (Estimate)
August 3, 2015
Last Update Submitted That Met QC Criteria
July 30, 2015
Last Verified
July 1, 2015
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- 39833-D
- P50ES015915 (U.S. NIH Grant/Contract)
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.