Secondhand Effects of Hookah (i.e., Waterpipe) Smoke and Aerosol

Study Overview
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Brief Summary
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In the United States, secondhand smoke is the third leading preventable cause of death. Flavored hookah (waterpipe) tobacco smoking, a highly social activity common in hookah bars, is a key source of SHS exposure. While smoke-free air laws have decreased exposure to secondhand smoke, the majority of laws do not include hookah smoking. Thus, as a social outlet for youth and young adults, hookah smoke exposure may harm non-smokers, including women of reproductive age or pregnant, hookah bar workers, children, and individuals with heart and lung disease. While more is known on the acute effects of active hookah smoking and the literature is emerging on active e-hookah vaping, little is known about the acute vascular effects of secondhand exposure to hookah smoke and aerosol. The study aims to examine the acute effects of secondhand exposure of hookah smoke and aerosol on endothelial and vascular function. Eligible volunteers will be invited to participate in a total of 3 study visits (2-3 hours each): e-hookah aerosol exposure, charcoal-heated hookah smoke exposure and smoke-free room air. Non-invasive blood pressure and blood flow measurements will be taken before and after the exposure sessions.

Official Title
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Investigating the Secondhand Effects of Hookah Smoking and Vaping

Conditions
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Hookah Smoking, Secondhand Aerosol, Vascular Stiffness, Vaping

Intervention / Treatment
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* Other: Combustible Hookah Smoke
* Other: Electronic Hookah Aerosol
* Other: Clean Room Air


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 21-49 years old Never a smoker: do not use any tobacco products or nicotine delivery systems, including cigarettes, cigars (traditional and filtered), cigarillos, hookah, smokeless tobacco (i.e., loose snus, moist snuff, dip, spit, or chewing tobacco), pipe tobacco, snus pouches, dissolvable tobacco or vaping. no evidence of cardiopulmonary disease by history/physical blood pressure (BP) < 140/90 mmHg resting heart rate (HR) < 100 bpm BMI >18 or < 30kg•m2 no prescription medication No exposure to environmental tobacco smoke for at least one week prior to the study date. Exclusion Criteria: exhaled carbon monoxide >6 ppm (+) pregnancy test other conditions deemed unsafe to participate, such as breastfeeding

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 49 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exposure to Combustible Hookah Smoke<br>Participants will be exposed to combustible hookah smoke. To mitigate the impact of carryover effects, the exposure sessions will be separated by a minimum of 7-days. | Other: Combustible Hookah Smoke<br>* Exposure to combustible hookah smoke for a duration of 60 minutes.<br>|
| Experimental: Exposure to Electronic Hookah Aerosol<br>Participants will be exposed to electronic hookah aerosol. To mitigate the impact of carryover effects, the exposure sessions will be separated by a minimum of 7-days. | Other: Electronic Hookah Aerosol<br>* Exposure to electronic hookah aerosol for a duration of 60 minutes.<br>|
| Experimental: Exposure to Clean Air<br>Participants will be exposed to Clean Room Air. To mitigate the impact of carryover effects, the exposure sessions will be separated by a minimum of 7-days. | Other: Clean Room Air<br>* Exposure to room air for a duration of 60 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flow-Mediated Dilation (FMD) | Using ultrasound, FMD of the brachial artery induced by reactive hyperemia, will be used to measure endothelium-dependent vasodilator function. Baseline diameter and velocity will be recorded for 45 seconds and resumed 30 seconds before cuff deflation and continuously for 2 minutes after deflation to obtain true peak vasodilatory response. | Pre- and post- the 60-minute exposure sessions | 
| Arterial stiffness | Using applanation tonometry, pulse wave velocity will be used to measure cebtral arterial stiffness. | Pre- and post- the 60-minute exposure sessions |