Electronic Hookah and Endothelial Cell Function

Study Overview
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Brief Summary
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Electronic nicotine delivery systems (ENDS) are a rapidly growing global epidemic among adolescents and young adults. Unlike other ENDS such as e-cigarettes, e-hookahs are used through traditional water-pipes, allowing the vapor-containing nicotine, propylene glycol, glycerin, and flavorings-to pass through a water-filled basin, potentially altering the vapor, before it is inhaled through the user's mouth. Contributing to e-hookahs popularity is the belief that the flavored smoke is detoxified as it passes through the water-filled basin, rendering e-hookah a safer tobacco alternative. However, an e-hookahs deliver flavored nicotine by creating a vapor of fine particles and volatile organic compounds that could induce vascular toxicity. While e-hookah vaping acutely reduces endothelial function, the specific role of nicotine and the mechanisms by which it may impairs endothelial function remain understudied. The objective of this project is to investigate the specific role of nicotine in mediating the acute effects of e-hookah vaping on endothelial dysfunction.

Official Title
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The Effects of Electronic Hookah on Endothelial Cell Function: The Role of Nicotine

Conditions
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Smoking, Endothelial Dysfunction

Intervention / Treatment
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* Other: Electronic hookah vaping with nicotine
* Other: Electronic hookah vaping without nicotine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 21-39 years old hookah smokers: smoked hookah >12x in last 12 months 21-39 years old e-cigarette users: vaped >12x in last 12 months no history of illicit drugs no evidence of cardiopulmonary disease by history/ physical no diabetes: fasting blood glucose <100 mg/dl BP<140/90mmHg resting HR<100 bpm BMI<30kg•m2 no prescription medication Exclusion Criteria: exhaled CO>10 ppm (smoking non-abstinence) positive pregnancy test psychiatric illness

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 39 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: e-hookah vaping with nicotine<br>Participants were invited to vape a 30-minute electronic hookah with nicotine vaping session, followed by a 30-minute electronic hookah without nicotine vaping session. To mitigate the impact of carryover effects, the two sessions were separated by a minimum of 7-days. | Other: Electronic hookah vaping with nicotine<br>* Participants will be invited to vape a 30-minute session of e-hookah containing nicotine<br>Other: Electronic hookah vaping without nicotine<br>* Participants will be invited to vape a 30-minute session of e-hookah without containing nicotine<br>|
| Experimental: e-hookah vaping without nicotine<br>Participants were invited to vape a 30-minute electronic hookah without nicotine vaping session, followed by a 30-minute electronic hookah with nicotine vaping session. To mitigate the impact of carryover effects, the two sessions were separated by a minimum of 7-days. | Other: Electronic hookah vaping with nicotine<br>* Participants will be invited to vape a 30-minute session of e-hookah containing nicotine<br>Other: Electronic hookah vaping without nicotine<br>* Participants will be invited to vape a 30-minute session of e-hookah without containing nicotine<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, was used to measure endothelium-dependent vasodilator function. Outcome variable reflecting FMD (brachial artery diameter) was recorded for 45 seconds and resumed 30 seconds before cuff deflation and continuously for 2 minutes after deflation to obtain true peak vasodilatory response. | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| Acetylcholine-stimulated nitric oxide production | Human umbilical vein endothelial cells were cultured with subjects' serum sampled before and after the vaping sessions and acetylcholine-stimulated nitric oxide production was assessed | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| Basal reactive oxygen species bioactivity | Human umbilical vein endothelial cells were cultured with participants' serum sampled before and after the vaping sessions and basal reactive oxygen species bioactivity was assessed | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| Fibrinogen levels | Plasma fibrinogen | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| Heme oxygenase-1 assay | Heme oxygenase-1 concentration assay | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| paraoxonase-1 activity | paraoxonase-1 activity | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| HDL protection assay | HDL protection assay, reflecting the ability of HDL to inhibit oxidation to LDL | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| Nicotine levels | Plasma nicotine | Changes pre- and post- the 30-minute smoking or vaping exposure sessions | 
| Carbon monoxide levels | Exhaled carbon monoxide levels | Changes pre- and post- the 30-minute smoking or vaping exposure sessions |