Controlled Exposure of Healthy Nonsmokers to Secondhand and Thirdhand Cigarette Smoke

NCT04013256 | Suspended

• 1 other identifier: 28PT-0081
• Study Type: interventional
• Target: 66
• Locations: 1 country
• Sites: 1

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.

Conditions

Pollution; Exposure; Smoke Inhalation; Exposure to Pollution

Outcome Measures

Primary Outcomes (1)

• 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.

  Baseline (before exposure) 30 minutes (after 30 minutes exposure) and 3 hours.

Secondary Outcomes (1)

• Changes in trans-epidermal water loss caused by pollution exposures, comparing intact skin to tape-stripped skin

  Baseline, 30 minutes, 3 hours, 2 days, 5 days

Study Arms (4)

Dermal Exposure to Thirdhand Cigarette Smoke

EXPERIMENTAL

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

Inhalational Exposure to Thirdhand Cigarette Smoke

ACTIVE COMPARATOR

Participants will breathe cigarette smoke aerosol that has been aged for 22 hours, for 3 hours while wearing clean clothing.

Other: Cigarette Smoke

Inhalational Exposure to Secondhand Cigarette Smoke

ACTIVE COMPARATOR

Participants will breathe cigarette smoke aerosol that has been aged for 30 minutes, for 3 hours while wearing clean clothing.

Other: Cigarette Smoke

Clean Air Exposure

SHAM COMPARATOR

Participants will breathe filtered, temperature and humidity controlled air while wearing clean clothing for 3 hours.

Other: Clean Air and Clean Clothing/Sham exposure

Interventions

Cigarette Smoke OTHER

Cigarette smoke, generated by a smoking machine and aged is used to reproduce exposure to secondhand and thirdhand cigarette smoke.

Dermal Exposure to Thirdhand Cigarette Smoke; Inhalational Exposure to Secondhand Cigarette Smoke; Inhalational Exposure to Thirdhand Cigarette Smoke

Clean Air and Clean Clothing/Sham exposure OTHER

Clean air, created by high-efficiency particulate air (HEPA) and charcoal filtration and temperature and humidity control. Clean cotton clothing.

Clean Air Exposure

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• University of California, San Francisco: lead
• Tobacco Related Disease Research Program: collaborator

Study Sites (1)

Zuckerberg San Francisco General Hospital

San Francisco, California, 94110, United States

Location

MeSH Terms

Conditions

Smoke Inhalation Injury

Condition Hierarchy (Ancestors)

Burns, Inhalation; Burns; Wounds and Injuries

Study Officials

• Suzaynn F Schick, PhD

  University of California, San Francisco

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Crossover assignment

Study Record Dates

• First Submitted: June 25, 2019
• First Posted: July 9, 2019
• Study Start: January 20, 2020
• Primary Completion: October 31, 2024
• Study Completion: October 31, 2024
• Last Updated: August 28, 2023

Record last verified: 2023-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: 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.

Locations

US (1)