Electronic Hookah and Endothelial Cell Function

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

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.

Study Overview

• Status: Completed
• Conditions: Smoking; Endothelial Dysfunction
• Intervention / Treatment: Other: Electronic hookah vaping with nicotine; Other: Electronic hookah vaping without nicotine

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90024
      • University of California, Los Angeles

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 39 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: e-hookah vaping with nicotine; 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; Participants will be invited to vape a 30-minute session of e-hookah containing nicotine; Other: Electronic hookah vaping without nicotine; Participants will be invited to vape a 30-minute session of e-hookah without containing nicotine
Experimental: e-hookah vaping without nicotine; 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; Participants will be invited to vape a 30-minute session of e-hookah containing nicotine; Other: Electronic hookah vaping without nicotine; Participants will be invited to vape a 30-minute session of e-hookah without containing nicotine

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: University of California, Los Angeles
• Collaborators: Tobacco Related Disease Research Program
• Investigators: Principal Investigator: Mary Rezk-Hanna, PhD, University of California, Los Angeles

Study record dates

Study Major Dates

• Study Start (Actual): January 16, 2020
• Primary Completion (Actual): November 29, 2022
• Study Completion (Actual): May 29, 2023

Study Registration Dates

• First Submitted: October 17, 2019
• First Submitted That Met QC Criteria: October 17, 2019
• First Posted (Actual): October 21, 2019

Study Record Updates

• Last Update Posted (Actual): March 12, 2026
• Last Update Submitted That Met QC Criteria: March 10, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Behavior; Smoking; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Alkaloids; Solanaceous Alkaloids; Nicotine
• Other Study ID Numbers: T30IP1013

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No