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Active, Not Recruiting

NCT Number: NCT04661683

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

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Hookah Smoking Behavior Pipe Smoking Secondhand Aerosol Smoking Vaping Vascular Stiffness Water Pipe Smoking

Age range

21 year–49 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of California, Los Angeles

Los Angeles, California, 90095-8361, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Combustible Hookah Smoke

Other

Exposure to combustible hookah smoke for a duration of 60 minutes.

Electronic Hookah Aerosol

Other

Exposure to electronic hookah aerosol for a duration of 60 minutes.

Clean Room Air

Other

Exposure to room air for a duration of 60 minutes.

Primary outcomes

  1. Flow-Mediated Dilation (FMD)

    Time frame: Pre- and post- the 60-minute exposure sessions

    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.

  2. Arterial stiffness

    Time frame: Pre- and post- the 60-minute exposure sessions

    Using applanation tonometry, pulse wave velocity will be used to measure cebtral arterial stiffness.

Sponsors and collaborators

Lead sponsor

University of California, Los Angeles

Other

Registry information

Official study title

Investigating the Secondhand Effects of Hookah Smoking and Vaping

Important dates

Study start
2021
Primary completion
2026
Study completion
2027
First posted
Dec 10, 2020
Registry last updated
Apr 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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