short-term cardiovascular effects of e-cigarettes: influence of device power

Conditions: Cardiovascular Risk Factor; Nicotine Dependence

Summary: this study will examine the short-term cardiovascular (cv) effects of e-cigarette device power in a randomized, crossover clinical and behavioral pharmacology study of experienced adult e-cigarette users (n=21). the specific aim is to determine the impact of e-cigarette power on nicotine pharmacology, systemic exposure to toxic volatile organic compounds (vocs), and short-term cardiovascular effects.

this is a single-site, randomized, crossover study of experienced adult e-cigarette users to assess nicotine exposure, toxicant exposure, and the short-term cv effects of e-cigarette power. three power levels will be assessed on all participants: 10, 15, and 20 watts. hypothesis 1a: systemic nicotine exposure and subjective measures of sensation in the throat, reward, and satisfaction will increase with increasing power in the e-cigarette device. hypothesis 1b: mercapturic acid metabolites of volatile organic compounds (vocs), particularly acrolein, will increase with e-cigarette power. hypothesis 1c: cv effects increase with higher power, and are manifested as changes in hemodynamic parameters, hormonal release, and biomarkers of endothelial function, platelet activation, inflammation, and oxidative stress.

Eligibility criteria:
inclusion criteria: * use e-cigarettes on at least 25 days in the past 30 for at least 3 months and have not used another tobacco product in the past 30 days * healthy on the basis of medical history and limited physical examination (screening visit), as described below: * heart rate \< 105 beats per minute (bpm)\* * systolic blood pressure \ 90\* * diastolic blood pressure \ 50\* * body mass index (bmi) ≤ 38.0 (at investigator's discretion for higher bmi if no other concurrent health issues) \*considered out of range if both machine and manual readings are above/below these thresholds. * any race/ethnicity exclusion criteria: * used tobacco products other than e-cigarettes in past 30 days * expired carbon monoxide of over 5 ppm at screening * the following unstable medical conditions: * heart disease * uncontrolled hypertension * thyroid disease (not hypo or hyper, controlled with medication) * diabetes * hepatitis b or c or liver disease * glaucoma * prostatic hypertrophy * psychiatric conditions: * current or past schizophrenia, and/or current or past bipolar disorder * adult onset attention deficit hyperactivity disorder (adhd) (if being treated) * participants with current or past depression and/or anxiety disorders will be reviewed by the study physician and considered for inclusion * psychiatric hospitalizations are not exclusionary, but study participation will be determined as per study physician's approval * drug/alcohol dependence: * alcohol or illicit drug dependence within the past 12 months with the exception of those who have recently completed an alcohol/drug treatment program * positive toxicology test at the screening visit (thc \& prescribed medications okay) * opioid replacement therapy * positive urine cannabis is not exclusionary but participant must report use of cannabis in any form on not more than 2 times per week to be eligible * psychiatric medications: * current regular use of any psychiatric medications with the exception of selective serotonin reuptake inhibitor (ssri) and serotonin-norepinephrine reuptake inhibitor (snris) and current evaluation by the study physician that the participant is otherwise healthy, stable, and able to participate. * medications * use of medications that are inducers of nicotine metabolizing enzyme cyp2a6 (example: rifampicin, dexamethasone, phenobarbital, and other anticonvulsant drugs). * concurrent use of nicotine-containing medications * other/misc. chronic health conditions * oral thrush * fainting * untreated thyroid disease * other "life threatening illnesses" as per study physician's discretion * pregnancy * pregnancy (self-reported and urine pregnancy test) * breastfeeding (determined by self-report) * concurrent participation in another clinical trial * inability to communicate in english * planning to quit smoking or vaping within the next 60 days

Keywords: e-cigarettes vaping e-cig mods