Effect of Commute Traffic on Vascular Function

July 8, 2022 updated by: Joel Daniel Kaufman, University of Washington
The investigators will assess the vascular effects of riding in a car in heavily trafficked roadways, and whether filtering the car's air reduces those effects.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

In this double-blind, crossover trial, randomized to order, recruited participants will be screened and then will accompany the study team on three typical commutes on separate days with sufficient washout (i.e., three weeks) between drives. One day this will occur with an effective filter system in the vehicle and the other two days without effective filtration; ineffective filtration is the most typical actual vehicle condition. Subjects will be unaware of the filtration conditions of the commute on that day. Each subject's experimental sessions will occur at the same time of day and will be separated by at least 21 days. The two sessions (either filtered air or traffic-derived entrained air) will be 120 minutes in duration and will encompass routes on heavily traveled roadways in the Seattle area. Before subjects begin the commute trials, they will go through the consent process and a series of screening tests. The study investigators will assess a series of measures regarding vascular function before and after each drive.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
16

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

  • United States
    • Washington
      • Seattle, Washington, United States, 98195
        • 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 49 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • healthy

Exclusion Criteria:

  • asthma,
  • high blood pressure,
  • diabetes,
  • high cholesterol,
  • other chronic conditions requiring ongoing medical care.

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: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
No Intervention: Typical Commute
Participants spend two hours in automobile, on heavily trafficked roadways, without active filtration of air pollutants
Other: Typical Commute, Filtered Air
Participants spend two hours in automobile, on heavily trafficked roadways, with active filtration of air pollutants
Other: Filtered Air
The vehicle is fitted with a (High-Efficiency Particulate Absorbing, HEPA) filter device incorporating a charcoal filter, as well as an augmented cabin filter

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Brachial Artery Diameter from Pre-Drive to Post-Drive
Time Frame: 30 minutes before 120 minute driving session; 30 minutes post driving session
Ultrasound assessment of brachial artery diameter, in millimeters.
30 minutes before 120 minute driving session; 30 minutes post driving session
Change in Blood Pressure from Pre-Drive to During-Drive and Post-drive
Time Frame: 10 minutes before driving session; 15, 30, 45, 60, 75, 90, 100, 120 minutes following start of (120 minute) driving session; 10 minutes, 1.5 hours, 3.5 hours, 6 hours, 24 hours after end of driving session.
systolic and diastolic blood pressure measured in mmHg
10 minutes before driving session; 15, 30, 45, 60, 75, 90, 100, 120 minutes following start of (120 minute) driving session; 10 minutes, 1.5 hours, 3.5 hours, 6 hours, 24 hours after end of driving session.
Change in Retinal Arteriolar Diameter from Pre-Drive to Post-Drive
Time Frame: 30 minutes before 120 minute driving session; 30 minutes post driving session
measured by retinal photography, image analysis, in micrometers
30 minutes before 120 minute driving session; 30 minutes post driving session
Gene Expression and DNA methylation
Time Frame: 30 minutes before 120 minute driving session; 30 minutes, 5 hour, and 24 hours post-driving session
analysis in circulating mononuclear cells; determined via fold change in abundance
30 minutes before 120 minute driving session; 30 minutes, 5 hour, and 24 hours post-driving session

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
circulating stress hormone
Time Frame: 30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session
cortisol by chemiluminescence (ng/mL)
30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session
complete blood count with differential
Time Frame: 30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session
laboratory values for hematologic indices (cells/uL)
30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session
inflammatory marker interleukin-6
Time Frame: 30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session
interleukin-6 determined by chemiluminescence (pg/mL)
30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session
inflammatory marker c-reactive protein
Time Frame: 30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session
C-reactive protein by immunoturbidimetry (ug/mL)
30 minutes before 120 minute driving session; 5 hour and 24 hours post-driving session

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Washington

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Environmental Health Sciences (NIEHS)
Environmental Protection Agency (EPA)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Joel Kaufman, MD, 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

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2015

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2016

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2016

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 31, 2015

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 8, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 12, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 12, 2022

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 8, 2022

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STUDY00001196
  • K24ES013195 (U.S. NIH Grant/Contract)
  • RD-83479601 (Other Grant/Funding Number: US Environmental Protection Agency STAR)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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.

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