Effects of Nicotine-Free Hookah Smoking on Blood Flow to the Heart, Muscle and Skin

Study Overview
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Brief Summary
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This is a pilot study on the acute effects of nicotine-free hookah (herbal/steam stones) smoking on the sympathetic neural control of the human cardiovascular system. Hookah smoking is known to transiently increase blood pressure and heart rate while decreasing heart rate variability suggesting - but not proving - sympathetic mediation. The contribution of nicotine to these effects is unknown. Here the investigators will directly measure the acute effects of nicotine-free Hookah smoking on sympathetic nerve activity with microneurography (intraneural microelectrodes) and quantify associated regional changes in vasomotor tone.

Official Title
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Effects of Nicotine-Free Hookah Smoking on Blood Flow to the Heart, Muscle and Skin

Conditions
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Nicotine-free Hookah Smoking

Intervention / Treatment
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* Other: Nicotine free hookah smoking


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 to 39 years of age Habitual Hookah smoker defined as having smoked Hookah >=12 times in the past 12 months Have not smoked cigarettes within the past 12 months Exclusion Criteria: Exhaled carbon monoxide level greater than 10 ppm* as evidence of current or recent cigarette (excluded if smoked cigarette within 12 months) or Hookah smoking (excluded if smoked Hookah within past 72 hours) History of cardiopulmonary disease Use of any prescription medication with exception of oral contraceptive pills History of psychiatric illness History of neurologic disease BMI ≥ 35 Evidence of any of the above by physical examination, ECG or echocardiogram Smoked cigarette in the past 12 months History of illicit drug use Pregnant Any other condition(s) deemed by the physician investigators that put subjects at risk for participating in the study

Ages Eligible for Study
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Minimum Age: 18 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Nicotine free hookah (herbal/steam stones) smoking<br>Healthy habitual Hookah smokers will undergo microneurography, myocardial contrast echocardiogram or venous occlusion plethysmography before and after nicotine free hookah smoking. | Other: Nicotine free hookah smoking<br>* Subjects will smoke waterpipe in a controlled research environment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in sympathetic nerve activity | Multi-unit recordings of sympathetic nerve activity will be obtained with single-use sterile tungsten microelectrodes inserted selectively into muscle or skin nerve fascicles of the peritoneal nerve. | Change from baseline in sympathetic nerve activity at 1 hr | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in regional myocardial perfusion | Myocardial contrast echocardiography will be used to measure regional myocardial perfusion (i.e. capillary blood volume) and coronary flow reserve. | Change from baseline in regional myocardial perfusion at 1 hr | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Smoking, Nicotine-free hookah, Waterpipe, Sympathetic