Back to resultsControlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke (THS04)
Primary Purpose
Pollution; Exposure, Smoke Inhalation, Exposure to Pollution
Status
Suspended
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Cigarette Smoke
Clean Air and Clean Clothing/Sham exposure
Sponsored by
About this trial
This is an interventional basic science trial for Pollution; Exposure
Eligibility Criteria
Inclusion Criteria:
- Healthy on the basis of medical history, blood pressure and test of C-reactive protein, lipids and blood sugar.
- Non-smoker not exposed to second-hand smoke (SHS) as determined by saliva cotinine < 10 ng/ml and tetrahydrocannabinol (THC) < 50 ng/ml.
- Flow mediated dilation of 4% or greater at screening visit.
Exclusion Criteria:
- Age 18 < or > 50 Physician diagnosis of asthma, heart disease, hypertension, thyroid disease, diabetes, renal or liver impairment or glaucoma.
Unstable psychiatric condition (such as current major depression, history of schizophrenia or bipolar disorder) or current use of more than two psychiatric medications Systolic blood pressure > 150 Diastolic blood pressure > 100 Blood glucose > 110 LDL >130 Pregnancy or breastfeeding (by urine Human Chorionic Gonadotropin (hCG) and/or history) Alcohol or illicit drug dependence within the past 5 years BMI > 35 and < 18 Current illicit drug use (by history or urine test) More than 1 pack year smoking history Ever a daily marijuana smoker Smoked anything within the last 3 months Unable to hold allergy or other over-the-counter (OTC) medicines Occupational exposure to smoke, dusts and fumes Concurrent participation in another clinical trial Unable to communicate in English No social security number
Sites / Locations
- Zuckerberg San Francisco General Hospital
Arms of the Study
Arm 1
Arm 2
Arm 3
Arm 4
Arm Type
Experimental
Active Comparator
Active Comparator
Sham Comparator
Arm Label
Dermal Exposure to Thirdhand Cigarette Smoke
Inhalational Exposure to Thirdhand Cigarette Smoke
Inhalational Exposure to Secondhand Cigarette Smoke
Clean Air Exposure
Arm Description
Participants will wear clothing that has been exposed to cigarette smoke, for 3 hours while breathing filtered, temperature and humidity controlled air.
Participants will breathe cigarette smoke aerosol that has been aged for 22 hours, for 3 hours while wearing clean clothing.
Participants will breathe cigarette smoke aerosol that has been aged for 30 minutes, for 3 hours while wearing clean clothing.
Participants will breathe filtered, temperature and humidity controlled air while wearing clean clothing for 3 hours.
Outcomes
Primary Outcome Measures
Changes in flow-mediated dilation (FMD) of the brachial artery, caused by pollution exposures, measured by ultrasound
High-resolution ultrasound of right brachial artery is performed 1 cm distal to antecubital fossa with a 10 megahertz (MHz) linear array probe coupled to a General Electric (GE) Vivid 7 Imaging System. To assess endothelium-dependent dilation, after recording baseline B-mode ultrasound images of the brachial artery and spectral Doppler images of flow velocity, a forearm cuff is inflated to 250 mmHg for 5 minutes to induce reactive hyperemia. Immediately after deflation, Doppler images are obtained to measure reactive hyperemia. FMD of brachial artery will be determined every 15 seconds between 30 and 120 seconds after cuff deflation to capture maximal dilation.The % FMD will be calculated as ratio between the maximum post cuff release brachial artery diameter and baseline diameter. By comparing changes in FMD before exposure, after exposure and next day, we will be able to assess effects of exposure on endothelial function and the potential recovery from these effects.
Secondary Outcome Measures
Changes in trans-epidermal water loss caused by pollution exposures, comparing intact skin to tape-stripped skin
We will measure trans-epidermal water loss (TEWL) on the volar forearm using a dermal relative humidity monitor (model IP52, Delfin Technologies Inc.) on adjacent circles of intact skin and skin that has been tape stripped prior to exposure. By comparing changes in TEWL at these two sites, before and after exposure and at day 2 and day 5, we will be able to detect any effects of dermal cigarette smoke exposure on skin barrier function and the rate of barrier function recovery.
Full Information
NCT ID
NCT04013256
First Posted
June 25, 2019
Last Updated
August 24, 2023
Sponsor
University of California, San Francisco
Collaborators
Tobacco Related Disease Research Program
1. Study Identification
Unique Protocol Identification Number
NCT04013256
Brief Title
Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke
Acronym
THS04
Official Title
Controlled Human Exposure and THS Generation Core
Study Type
Interventional
2. Study Status
Record Verification Date
August 2023
Overall Recruitment Status
Suspended
Why Stopped
The human exposure facility was closed by the University.
Study Start Date
January 20, 2020 (Actual)
Primary Completion Date
October 31, 2024 (Anticipated)
Study Completion Date
October 31, 2024 (Anticipated)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
University of California, San Francisco
Collaborators
Tobacco Related Disease Research Program
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No
5. Study Description
Brief Summary
This study compares the health effects of dermal and inhalational exposure to thirdhand cigarette smoke to those of inhalational exposure to secondhand cigarette smoke in healthy, adult nonsmokers. Our hypothesis is that dermal exposure increases exposure to the tobacco specific carcinogen, NNK and may affect both endothelial function and epidermal integrity.
Detailed Description
Thirdhand cigarette smoke is the smoke chemicals that persist in the environment after smoking. Indoors, they can be found both on surfaces and in the air. Thirdhand smoke derives from secondhand smoke and contains the chemicals that stick to surfaces, are re-emitted into the air and that form by chemical reactions both on surfaces and in the air.
Thirdhand smoke can contain higher concentrations of the tobacco-specific nitrosamine and known carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) than secondhand smoke, because nicotine reacts to form NNK in the indoor environment. Dermal exposure to thirdhand smoke includes nicotine, NNK and other tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, and volatile organic compounds. Inhalational exposure to thirdhand smoke includes nicotine, ultrafine particles and volatile organic compounds. Previous studies have shown that inhalational exposure to secondhand cigarette smoke causes endothelial dysfunction, which is a risk factor for heart disease and heart attacks.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Pollution; Exposure, Smoke Inhalation, Exposure to Pollution
7. Study Design
Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Model Description
Crossover assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
66 (Anticipated)
8. Arms, Groups, and Interventions
Arm Title
Dermal Exposure to Thirdhand Cigarette Smoke
Arm Type
Experimental
Arm Description
Participants will wear clothing that has been exposed to cigarette smoke, for 3 hours while breathing filtered, temperature and humidity controlled air.
Arm Title
Inhalational Exposure to Thirdhand Cigarette Smoke
Arm Type
Active Comparator
Arm Description
Participants will breathe cigarette smoke aerosol that has been aged for 22 hours, for 3 hours while wearing clean clothing.
Arm Title
Inhalational Exposure to Secondhand Cigarette Smoke
Arm Type
Active Comparator
Arm Description
Participants will breathe cigarette smoke aerosol that has been aged for 30 minutes, for 3 hours while wearing clean clothing.
Arm Title
Clean Air Exposure
Arm Type
Sham Comparator
Arm Description
Participants will breathe filtered, temperature and humidity controlled air while wearing clean clothing for 3 hours.
Intervention Type
Other
Intervention Name(s)
Cigarette Smoke
Intervention Description
Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.
Intervention Type
Other
Intervention Name(s)
Clean Air and Clean Clothing/Sham exposure
Intervention Description
Clean air, created by high-efficiency particulate air (HEPA) and charcoal filtration and temperature and humidity control.
Clean cotton clothing.
Primary Outcome Measure Information:
Title
Changes in flow-mediated dilation (FMD) of the brachial artery, caused by pollution exposures, measured by ultrasound
Description
High-resolution ultrasound of right brachial artery is performed 1 cm distal to antecubital fossa with a 10 megahertz (MHz) linear array probe coupled to a General Electric (GE) Vivid 7 Imaging System. To assess endothelium-dependent dilation, after recording baseline B-mode ultrasound images of the brachial artery and spectral Doppler images of flow velocity, a forearm cuff is inflated to 250 mmHg for 5 minutes to induce reactive hyperemia. Immediately after deflation, Doppler images are obtained to measure reactive hyperemia. FMD of brachial artery will be determined every 15 seconds between 30 and 120 seconds after cuff deflation to capture maximal dilation.The % FMD will be calculated as ratio between the maximum post cuff release brachial artery diameter and baseline diameter. By comparing changes in FMD before exposure, after exposure and next day, we will be able to assess effects of exposure on endothelial function and the potential recovery from these effects.
Time Frame
Baseline (before exposure) 30 minutes (after 30 minutes exposure) and 3 hours.
Secondary Outcome Measure Information:
Title
Changes in trans-epidermal water loss caused by pollution exposures, comparing intact skin to tape-stripped skin
Description
We will measure trans-epidermal water loss (TEWL) on the volar forearm using a dermal relative humidity monitor (model IP52, Delfin Technologies Inc.) on adjacent circles of intact skin and skin that has been tape stripped prior to exposure. By comparing changes in TEWL at these two sites, before and after exposure and at day 2 and day 5, we will be able to detect any effects of dermal cigarette smoke exposure on skin barrier function and the rate of barrier function recovery.
Time Frame
Baseline, 30 minutes, 3 hours, 2 days, 5 days
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
50 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria:
Healthy on the basis of medical history, blood pressure and test of C-reactive protein, lipids and blood sugar.
Non-smoker not exposed to second-hand smoke (SHS) as determined by saliva cotinine < 10 ng/ml and tetrahydrocannabinol (THC) < 50 ng/ml.
Flow mediated dilation of 4% or greater at screening visit.
Exclusion Criteria:
Age 18 < or > 50 Physician diagnosis of asthma, heart disease, hypertension, thyroid disease, diabetes, renal or liver impairment or glaucoma.
Unstable psychiatric condition (such as current major depression, history of schizophrenia or bipolar disorder) or current use of more than two psychiatric medications Systolic blood pressure > 150 Diastolic blood pressure > 100 Blood glucose > 110 LDL >130 Pregnancy or breastfeeding (by urine Human Chorionic Gonadotropin (hCG) and/or history) Alcohol or illicit drug dependence within the past 5 years BMI > 35 and < 18 Current illicit drug use (by history or urine test) More than 1 pack year smoking history Ever a daily marijuana smoker Smoked anything within the last 3 months Unable to hold allergy or other over-the-counter (OTC) medicines Occupational exposure to smoke, dusts and fumes Concurrent participation in another clinical trial Unable to communicate in English No social security number
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Suzaynn F Schick, PhD
Organizational Affiliation
University of California, San Francisco
Official's Role
Principal Investigator
Facility Information:
Facility Name
Zuckerberg San Francisco General Hospital
City
San Francisco
State/Province
California
ZIP/Postal Code
94110
Country
United States
12. IPD Sharing Statement
Plan to Share IPD
Yes
IPD Sharing Plan Description
We will share the individual participant data (IPD) that underlie the results in our publications.
IPD Sharing Time Frame
9 months after publication
IPD Sharing Access Criteria
Data will be made available to researchers who submit a detailed and well-supported description of their research plans.
Learn more about this trial
Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke
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