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Investigating the Cardiovascular Toxicity of Exposure to Electronic Hookah Smoking

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ClinicalTrials.gov Identifier: NCT03690427
Recruitment Status : Recruiting
First Posted : October 1, 2018
Last Update Posted : March 25, 2019
Sponsor:
Collaborators:
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Mary Rezk-Hanna, PhD, University of California, Los Angeles

Brief Summary:
Hookah (water-pipe) smoking has quickly grown to become a major global tobacco epidemic among youth; with electronic hookahs more recently increasing in popularity especially among young female adults, who endorse marketing claims that these products are a safer alternative to traditional hookah, but scientific evidence is lacking. The study aims to elucidate the comparative effects of traditional hookah smoking vs. electronic hookah inhalation on human vascular and endothelial function; and examine the role of inflammation and oxidative stress as likely mechanisms in hookah-related cardiovascular disease pathogenesis.

Condition or disease Intervention/treatment Phase
Smoking Endothelial Dysfunction Other: Traditional hookah smoking Other: Electronic hookah inhalation Not Applicable

Detailed Description:
Hookah (water-pipe) smoking is rapidly increasing in popularity worldwide. Contributing to this popularity is the unsubstantiated belief that traditional hookah smoke is detoxified as it passes through the water-pipe. More recently, electronic hookah bowls—containing e-liquid that is heated electrically but inhaled through traditional water-pipes—are increasing in popularity in the United States among young female adults, who endorse marketing claims that these products are even safer than traditional hookah. With traditional hookah, in addition to nicotine and tar, smokers are exposed to carbon-enriched fine particles and significant amounts of carbon monoxide (CO), the latter of which has been shown to constitute an endothelial-dependent vasodilator. Though toxicant exposure is much lower than traditional hookah and without any CO exposure, e-hookah bowls deliver nicotine and fine particles that constitute putative vascular toxins. The main objective of this project is to investigate the comparative effects of traditional hookah smoking versus electronic hookah bowl inhalation on endothelial and vascular function and their mechanistic role in the development of cardiovascular disease. Specifically, the investigators will examine the role of oxidative stress and inflammation as potential mechanisms of action in hookah-induced cardiovascular disease. The investigators will test the hypothesis that; 1) in the absence of charcoal briquettes and virtually any CO exposure, e-hookah bowl inhalation acutely impairs endothelial function and evokes acute central stiffness, opposite from the endothelial function augmentation observed after traditional hookah smoking, which is likely mediated by the large CO boost emitted from burning charcoal briquettes used to heat the flavored tobacco; and 2) the processes of oxidative stress and inflammation play a pivotal mechanistic role underlying these vascular changes. In a cross-over study comparing traditional hookah smoking to e-hookah bowl inhalation, the investigators will assess endothelial function measured by brachial artery flow-mediated dilation and aortic stiffness by pulse wave velocity and augmentation index in 18 young healthy hookah smokers 21-39 years old, before and after ad lib 30-minute smoking/ inhalation session. To test for oxidative stress mediation, the investigators will determine if any acute impairment in endothelial function after e-hookah can be prevented by intravenous Vitamin C infusion, a potent anti-oxidant. Antioxidant defensive buffers, such as protective HDL or paraoxonase-1 activity, or an increase in oxidized lipoproteins will be collected. To test for inflammatory mediation, biomarkers including anti-inflammatory cytokine IL-10 and pro-inflammatory cytokines hsCRP, TNF-α, IL-6, IL-8 will be collected before and after the sessions as well as smoking exposure biomarkers (plasma nicotine and expired CO). The results of this proposal: (a) stand to fill in gaps in our mechanistic understanding of the comparative effect of traditional vs. e-hookah bowl on vascular and endothelial function; and (b) help inform policy decisions by the FDA about regulation of hookah products.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 18 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: Charcoal-heated hookah vs. Electronic hookah bowl
Masking: None (Open Label)
Primary Purpose: Other
Official Title: Investigating the Cardiovascular Toxicity of Exposure to Electronic Hookah Smoking
Actual Study Start Date : September 15, 2018
Estimated Primary Completion Date : August 31, 2020
Estimated Study Completion Date : August 31, 2020

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Smoking

Arm Intervention/treatment
Experimental: Endothelial function
Brachial artery flow-mediated dilation will be used to measure endothelial function
Other: Traditional hookah smoking
Charcoal-heated hookah smoking

Other: Electronic hookah inhalation
Electronic hookah bowl

Experimental: Arterial Stiffness
Pulse wave velocity will be used to measure arterial stiffness
Other: Traditional hookah smoking
Charcoal-heated hookah smoking

Other: Electronic hookah inhalation
Electronic hookah bowl

Experimental: Biomarkers of
Prooxidant and inflammatory plasma biomarkers will be used to assess oxidative stress and inflammatory status
Other: Traditional hookah smoking
Charcoal-heated hookah smoking

Other: Electronic hookah inhalation
Electronic hookah bowl




Primary Outcome Measures :
  1. Acute effects of e-hookah bowl inhalation on endothelial function. [ Time Frame: 30 minutes ]
    ∆Flow-Mediated Dilation (FMD), % from pre- to post- cuff occlusion performed before and after each exposure experiment.

  2. Acute effects of e-hookah bowl inhalation on central arterial stiffness. [ Time Frame: 30 minutes ]
    ∆pulse wave velocity, m/s−1 before and after each exposure experiment.

  3. Acute effects of e-hookah bowl inhalation on biomarkers of oxidative stress and inflammation. [ Time Frame: 30 minutes ]
    ∆LDL-ox before and after each exposure experiment.

  4. Acute effects of e-hookah bowl inhalation on biomarkers of oxidative stress and inflammation. [ Time Frame: 30 minutes ]
    ∆hsCRP before and after each exposure experiment.

  5. Acute effects of e-hookah bowl inhalation on biomarkers of oxidative stress and inflammation. [ Time Frame: 30 minutes ]
    ∆TNF-α before and after each exposure experiment.



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Ages Eligible for Study:   21 Years to 39 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • 21-39 years old hookah smokers: smoked hookah >12x in last 12 months
  • no history of illicit drugs or marijuana
  • 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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03690427


Contacts
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Contact: Mary Rezk-Hanna, PhD (310) 206-8654 MRHanna@mednet.ucla.edu

Locations
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United States, California
University of California, Los Angeles Recruiting
Los Angeles, California, United States, 90095-8361
Contact: Elda Solomon    310-562-4348    Easolomon@mednet.ucla.edu   
Sponsors and Collaborators
University of California, Los Angeles
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)

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Responsible Party: Mary Rezk-Hanna, PhD, Principal Investigator, University of California, Los Angeles
ClinicalTrials.gov Identifier: NCT03690427     History of Changes
Other Study ID Numbers: 1R21HL145002-01 ( U.S. NIH Grant/Contract )
1R21HL145002-01 ( U.S. NIH Grant/Contract )
First Posted: October 1, 2018    Key Record Dates
Last Update Posted: March 25, 2019
Last Verified: September 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No