NCT00434005

Brief Summary

Objectives: This proposal addresses the overall hypothesis that ambient fine particulate matter exerts cardiovascular health effects via alteration of endothelial homeostasis, through a mechanism mediated by oxidative stress. This project will use a controlled human inhalation exposure to diesel exhaust particulate (DEP) as a model to address the following objectives: 1) Determine whether exposure to inhaled DEP is associated with endothelial dysfunction in a concentration-related manner; 2) Determine whether exposure to inhaled DEP is associated with evidence of systemic oxidative stress; and 3) Determine whether antioxidant supplementation blunts the DEP effect on endothelial function.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
24

participants targeted

Target at P25-P50 for not_applicable healthy

Timeline
Completed

Started Jul 2008

Longer than P75 for not_applicable healthy

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

August 25, 2006

Completed
6 months until next milestone

First Posted

Study publicly available on registry

February 12, 2007

Completed
1.4 years until next milestone

Study Start

First participant enrolled

July 1, 2008

Completed
2.1 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 1, 2010

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

August 1, 2010

Completed
Last Updated

January 16, 2013

Status Verified

January 1, 2013

Enrollment Period

2.1 years

First QC Date

August 25, 2006

Last Update Submit

January 14, 2013

Conditions

Keywords

Air pollutiondieselantioxidantoxidative stressendothelialHRVBAR

Outcome Measures

Primary Outcomes (1)

  • Brachial artery caliber

    Pre-exposure, immediate post-exposure

Secondary Outcomes (3)

  • Brachial Artery Flow-Mediated Dilation

    Post-Exposure

  • Plasma Endothelin-1

    Post-exposure (adjusted for pre-exposure level)

  • Serum IL-6

    Post-exposure (adjusted for pre-exposure level)

Study Arms (2)

Diesel Exhaust

EXPERIMENTAL
Drug: N-acetylcysteine, ascorbateDrug: Placebo

Filtered Air

SHAM COMPARATOR
Drug: N-acetylcysteine, ascorbateDrug: Placebo

Interventions

NAC: 600mg twice daily for the day prior to exposure and 1x pre-exposure Ascorbate: 500mg twice daily for 7 days prior to exposure

Diesel ExhaustFiltered Air

matched appearance to acetylcysteine and ascorbate intervention

Diesel ExhaustFiltered Air

Eligibility Criteria

Age18 Years - 49 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Healthy adults aged 18-49.

You may not qualify if:

  • Nonsmokers, no history of hypertension, asthma, diabetes, hypercholesterolemia, or other chronic conditions requiring ongoing medical care. No recent history of antioxidant, vitamin/mineral/botanical, or fatty acid supplementation beyond a daily multi-vitamin.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Northlake Laboratory

Seattle, Washington, 98105, United States

Location

Related Publications (1)

  • Cosselman KE, Krishnan RM, Oron AP, Jansen K, Peretz A, Sullivan JH, Larson TV, Kaufman JD. Blood pressure response to controlled diesel exhaust exposure in human subjects. Hypertension. 2012 May;59(5):943-8. doi: 10.1161/HYPERTENSIONAHA.111.186593. Epub 2012 Mar 19.

Related Links

MeSH Terms

Interventions

Acetylcysteine

Intervention Hierarchy (Ancestors)

CysteineAmino Acids, SulfurSulfur CompoundsOrganic ChemicalsAmino AcidsAmino Acids, Peptides, and Proteins

Study Officials

  • Joel D Kaufman, M.D., MPH

    University of Washington

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

August 25, 2006

First Posted

February 12, 2007

Study Start

July 1, 2008

Primary Completion

August 1, 2010

Study Completion

August 1, 2010

Last Updated

January 16, 2013

Record last verified: 2013-01

Locations