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Trial record 20 of 769 for:    Tobacco Smoke

Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke (THS04)

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ClinicalTrials.gov Identifier: NCT04013256
Recruitment Status : Not yet recruiting
First Posted : July 9, 2019
Last Update Posted : July 9, 2019
Sponsor:
Information provided by (Responsible Party):
Suzaynn Schick, University of California, San Francisco

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.

Condition or disease Intervention/treatment Phase
Pollution; Exposure Smoke Inhalation Exposure to Pollution Other: Cigarette Smoke Other: Clean Air and Clean Clothing/Sham exposure Not Applicable

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.


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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 66 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: Crossover assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Controlled Human Exposure and THS Generation Core
Estimated Study Start Date : July 2019
Estimated Primary Completion Date : April 2022
Estimated Study Completion Date : July 2022

Arm Intervention/treatment
Experimental: Dermal Exposure to Thirdhand Cigarette Smoke
Participants will wear clothing that has been exposed to cigarette smoke, for 3 hours while breathing filtered, temperature and humidity controlled air.
Other: Cigarette Smoke
Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Active Comparator: Inhalational Exposure to Thirdhand Cigarette Smoke
Participants will breathe cigarette smoke aerosol that has been aged for 22 hours, for 3 hours while wearing clean clothing.
Other: Cigarette Smoke
Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Active Comparator: Inhalational Exposure to Secondhand Cigarette Smoke
Participants will breathe cigarette smoke aerosol that has been aged for 30 minutes, for 3 hours while wearing clean clothing.
Other: Cigarette Smoke
Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Sham Comparator: Clean Air Exposure
Participants will breathe filtered, temperature and humidity controlled air while wearing clean clothing for 3 hours.
Other: Clean Air and Clean Clothing/Sham exposure

Clean air, created by HEPA and charcoal filtration and temperature and humidity control.

Clean cotton clothing.





Primary Outcome Measures :
  1. Changes in flow-mediated dilation of the brachial artery, caused by pollution exposures, measured by ultrasound [ Time Frame: Baseline (before exposure) 30 minutes (after 30 minutes exposure) and 3 hours. ]
    High-resolution ultrasound of the right brachial artery is performed 1 cm distal to the antecubital fossa with a 10MHz linear array probe coupled to a 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 the 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 the ratio between the maximum post cuff release brachial artery diameter and the baseline diameter. By comparing changes in FMD before exposure, after exposure and the next day, we will be able to assess the effects of exposure on endothelial function and the potential recovery from these effects.


Secondary Outcome Measures :
  1. Changes in trans-epidermal water loss caused by pollution exposures, comparing intact skin to tape-stripped skin [ Time Frame: Baseline, 30 minutes, 3 hours, 2 days, 5 days ]
    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.



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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
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 SHS as determined by saliva cotinine < 10 ng/ml and 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 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 OTC medicines Occupational exposure to smoke, dusts and fumes Concurrent participation in another clinical trial Unable to communicate in English No social security number


Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04013256


Contacts
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Contact: Suzaynn F Schick, PhD 628-206-5904 suzaynn.schick@ucsf.edu
Contact: Abel Huang, BA 415-6286685 abel.huang@ucsf.edu

Sponsors and Collaborators
University of California, San Francisco
Investigators
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Principal Investigator: Suzaynn F Schick, PhD University of California, San Francisco

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Responsible Party: Suzaynn Schick, Associate Professor of Medicine, University of California, San Francisco
ClinicalTrials.gov Identifier: NCT04013256     History of Changes
Other Study ID Numbers: 28PT-0081
First Posted: July 9, 2019    Key Record Dates
Last Update Posted: July 9, 2019
Last Verified: July 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Plan Description: We will share the IPD that underlie the results in our publications.
Supporting Materials: Study Protocol
Time Frame: 9 months after publication
Access Criteria: Data will be made available to researchers who submit a detailed and well-supported description of their research plans.

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Additional relevant MeSH terms:
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Smoke Inhalation Injury
Burns, Inhalation
Burns
Wounds and Injuries