Diesel Exhaust and Vascular Function

Summary

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.

Conditions

• Cardiovascular Effects

Interventions

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

Sponsors & Collaborators

• National Institute of Environmental Health Sciences (NIEHS)

  collaborator NIH

• Environmental Protection Agency (EPA)

  collaborator FED

• University of Washington

  lead OTHER

Principal Investigators

• Joel D Kaufman, MD, MPH · University of Washington

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

TRIPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

49 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2012-01-31

Primary Completion

2015-12-31

Completion

2015-12-31

Countries

• United States

Study Locations