Diesel Exhaust and Vascular Function (CVDTRAP4)

University of Washington

Status: Unknown

Conditions: Cardiovascular Effects

Treatments: Other: Diesel Exhaust; Other: Filtered Air; Drug: placebo; Drug: Terazosin

Study type: Interventional

Funder types: Other; Other U.S. Federal agency; NIH

Identifiers

NCT01508637

P50ES015915 (U.S. NIH Grant/Contract)

39833-D

Details and patient eligibility

About

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.

Enrollment: 24 estimated patients

Sex: All

Ages: 18 to 49 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Triple Blind

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24 participants in 4 patient groups

Diesel Exhaust + Terazosin

Experimental group

Treatment:

Drug: Terazosin

Other: Diesel Exhaust

Diesel Exhaust + placebo

Experimental group

Treatment:

Drug: placebo

Other: Diesel Exhaust

Filtered Air + terazosin

Sham Comparator group

Treatment:

Drug: Terazosin

Other: Filtered Air

Filtered air + placebo

Sham Comparator group

Treatment:

Drug: placebo

Other: Filtered Air