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Completed

NCT Number: NCT05454930

Effect of Commute Traffic on Vascular Function

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.

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Key information

Conditions

Cardiovascular Diseases

Age range

18 year–49 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Washington Medical Center

Seattle, Washington, 98195, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • healthy

Exclusion criteria

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

Treatment and study plan

Filtered Air

Other

The vehicle is fitted with a (High-Efficiency Particulate Absorbing, HEPA) filter device incorporating a charcoal filter, as well as an augmented cabin filter

Primary outcomes

  1. 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.

  2. 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

  3. 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

  4. 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

Secondary outcomes

  1. 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)

  2. 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)

  3. 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)

  4. 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)

Sponsors and collaborators

Lead sponsor

University of Washington

Other

Collaborators

  • Environmental Protection Agency (EPA)
  • National Institute of Environmental Health Sciences (NIEHS)

Registry information

Important dates

Study start
2015
Primary completion
2016
Study completion
2016
First posted
Jul 12, 2022
Registry last updated
Jul 12, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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