Mental Stress & Diesel Exhaust on Cardiovascular Health

Not Applicable

• Conditions: Blood Pressure; Inflammation; Catecholamines
• Interventions: Behavioral: Trier social stress test; Other: Diesel exhaust

• Registration Number: NCT03467997
• Lead Sponsor: University of Washington

Brief Summary

This study uses an experimental design to conduct a double-blind, randomized, crossover study where participants receive both diesel exhaust and a mental stress test in a controlled setting. My hypothesis is that the synergistic effect of stress and air pollution will result in higher levels of stress and inflammation (measured via biological markers) as well as poorer cardiovascular disease related outcomes compared to the independent effect of each exposure separately.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2017-12-12
• Study First Submitted QC: 2018-03-10
• Study First Posted: 2018-03-16
• Study Start: 2018-03-22
• Status Verified: 2018-11
• Last Update Submitted: 2018-11-01
• Last Update Posted: 2018-11-05
• Primary Completion: 2020-01
• Study Completion: 2020-01

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 22

Inclusion Criteria

Non-smokers without history of high blood pressure, asthma, diabetes, high cholesterol, post-traumatic stress disorder (PTSD) or any other chronic condition that requires ongoing care.

Exclusion Criteria

1. Smoking: We rule out active smoking by checking urine cotinine during our study.
2. History of high blood pressure: We objectively measure BP during in-person screening and exclude those with blood pressure (>130/85 mmHg).
3. Asthmatic: Spirometry is done at screening to rule out asthma.
4. Diabetic: We obtain fasting blood sugar to rule out diabetes at screening (>125 mg/dL)
5. Cholesterol: We obtain fasting blood lipid levels to rule out hypercholesterolemia at screening (>200 mg/dL).
6. History of PTSD: Subjects will be asked about prior PTSD diagnosis during the phone and in person screen.
7. Any other chronic condition requiring ongoing care based on medication use.
8. A body mass index (weight in kilograms divided by height in meters squared) greater than 26 and less than 18.5
9. A female of childbearing age with a positive pregnancy test
10. A female of childbearing age who is unwilling to use effective contraception during the study

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
TSST/Stress only	Trier social stress test	Subjects undergo a mental stress test, known as the Trier Social Stress Test (TSST), which involves a public speaking and math task.
Diesel Exhaust	Diesel exhaust	Subjects sit in a room for two hours breathing in diesel exhaust at 200 micrograms of meter cubed.
Diesel Exhaust and stress	Diesel exhaust	Subjects sit in a room for two hours breathing in diesel exhaust at 200 micrograms of meter cubed and are subject to a mental stress test (TSST) which involves a public speaking and math task.
Diesel Exhaust and stress	Trier social stress test	Subjects sit in a room for two hours breathing in diesel exhaust at 200 micrograms of meter cubed and are subject to a mental stress test (TSST) which involves a public speaking and math task.

Primary Outcome Measures

Name	Time	Method
Change in norepinephrine	Change in norepinephrine from baseline (pre-exposure) to immediately after exposure	Urinary norepinephrine in ng/mg
Change in epinephrine	Change in epinephrine from baseline (pre-exposure) to immediately after exposure	Urinary epinephrine in ng/mg
Change in dopamine	Change in dopamine from baseline (pre-exposure) to immediately after exposure	Urinary dopamine in ng/mg

Secondary Outcome Measures

Name	Time	Method
Change in d-dimer	change in d-dimer from baseline (pre-exposure) to six hours post exposure	plasma d-dimer (ug/ml) is a measure of coagulation
Change in fibrinogen	change in fibrinogen from baseline (pre-exposure) to six hours post exposure	plasma fibrinogen (mg/dl) is a measure of coagulation
Change in interleukin-6 (IL-6)	change in IL-6 from baseline (pre-exposure) to immediately after exposure	plasma IL-6, measured in pg/ml, is a marker of inflammation
Change in interleukin-1b (IL-1b)	change in IL-1b from baseline (pre-exposure) to immediately after exposure	plasma IL-1b, measured in pg/ml, is a marker of inflammation
Change in tumor necrosis factor alpha (TNF-a)	change in TNF-a from baseline (pre-exposure) to immediately after exposure	plasma TNF-a, measured in pg/ml, is a marker of inflammation

Trial Locations

Locations (1)

University of Washington Diesel Exhaust Facility; 🇺🇸 Seattle, Washington, United States