Comparison of Electronic Cigarettes and Tobacco Cigarettes on Cardiovascular Function and Oxidative Stress

Study Overview
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Brief Summary
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Background: Electronic cigarettes (e-cigarettes) are battery-powered devices heating a liquid (e-liquid) composed of propylene glycol and/or vegetable glycerin, and most commonly, nicotine to form an aerosol (vapor) that is inhaled (i.e. vaped). Scarce and conflicting data are available regarding the cardiovascular toxicity of e-cigarettes. We wish to determine the acute effects of propylene glycol/vegetable glycerin and nicotine vaporization at high temperature in comparison to tobacco cigarette smoking on several advanced cardiovascular parameters in healthy chronic e-cigarettes users and tobacco smokers. Furthermore, a large range of plasma, urine and respiratory oxidative stress markers will be quantified. By this way, we aim to demonstrate that e-cigarettes-induced systemic oxidative stress could be linked to cardiovascular toxicity. To the best of our knowledge, this is the first project that evaluates the effects of e-cigarettes vaping in comparison to tobacco cigarette smoking on the cardiovascular system in relation to vaporization temperature, nicotine delivery and oxidative stress. Aims of the study: This study tests the following hypotheses: 1) acute high temperature vaporization of propylene glycol and vegetable glycerin has no deleterious effects on cardiovascular parameters in comparison to tobacco smoking; 2) Tobacco smoking rises plasma and urine oxidative stress biomarkers. On the contrary, acute and chronic e-cigarettes vaping don't rise these biomarkers. At a cellular level, plasma of smokers but not vapers increases superoxide anion production.

Official Title
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Effects of Electronic Cigarette Vaporization at High Temperature in Comparison to Tobacco Smoking on Cardiovascular Function and Oxidative Stress in Electronic Cigarette Users and Regular Tobacco Smokers

Conditions
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Cardiovascular Risk Factor

Intervention / Treatment
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* Device: e-cigarette (PG+VG without nicotine; low temperature)
* Device: e-cigarette (PG+VG with nicotine; low temperature)
* Device: e-cigarette (PG+VG without nicotine; high temperature)
* Device: e-cigarette (PG+VG with nicotine; high temperature)
* Other: tobacco cigarette


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy subjects Exclusion Criteria: Any form of cardiovascular disease Any form of pulmonary disease like asthma or COPD Any form of systemic or chronic disorder Active allergy within 4 weeks of the study Symptoms of infection or inflammation within 4 weeks of the study Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: e-cigarette nic_O LT<br>e-cigarette (without nicotine; low temperature) | Device: e-cigarette (PG+VG without nicotine; low temperature)<br> <br> |
| Experimental: e-cigarette Nic_1 LT<br>e-cigarette (with nicotine; low temperature) | Device: e-cigarette (PG+VG with nicotine; low temperature)<br> <br> |
| Experimental: e-cigarette Nic_0 HT<br>e-cigarette (without nicotine; high temperature) | Device: e-cigarette (PG+VG without nicotine; high temperature)<br> <br> |
| Experimental: e-cigarette NIC_1 HT<br>e-cigarette (with nicotine; high temperature) | Device: e-cigarette (PG+VG with nicotine; high temperature)<br> <br> |
| Active Comparator: Tobacco cigarette<br>Tobacco cigarette | Other: tobacco cigarette<br> <br> |
| Placebo Comparator: Placebo<br>No E-cigarettes, Nor tobocco cigarettes | Device: e-cigarette (PG+VG without nicotine; low temperature)<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in subcutaneous flux |  | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Plasma and urine oxidative stress markers |  | 1 hour | 
| Change in aortic stiffness |  | 10 minutes | 
| Change in heart rate variability |  | 10 minutes | 
| Change in baroreflex sensitivity |  | 10 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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electronic cigarette, e-cigarette, oxidative stress, tobacco smoking