Background: The understanding of electronic cigarettes (ECs) and their potentially deleterious effects on health outcomes are lacking compared to the increasing use and evolvement of these devices. Research that explores determinants of health effects such as acute physiological responses, individual expectations, social factors, and emotional well-being may address issues that will likely arise with long-term EC use. Examining characteristics, motivations, and health-risk behaviors may also provide valuable insights into behavioral trends and conditions associated with EC use and identify groups in need of targeted interventions. Study Design: there were two separate arms for this study: quasi-experimental pretest-posttest control design involving vascular and pulmonary testing and a cross-sectional, Internet-based survey. Purpose: The purposes of Arm I include 1) to examine baseline vascular and pulmonary health differences between tobacco-na�ive controls and chronic EC users, and 2) to examine the acute vascular and pulmonary health effects of a single vaping session in chronic EC users. The purposes of Arm 2 include 1) to explore associations among EC use, health-related quality of life, and perceived health effects in a diverse sample of adults in the United States, 2) to examine the association between sociodemographic factors and EC use, and 3) to examine motivations and patterns of use within EC users. Methods: Eight healthy EC users and eight age-matched controls recruited from the university campus and the surrounding area participated in Arm 1 of this study. All subjects completed assessments of spirometry and flow-mediated dilation (FMD) of the brachial artery, respectively. EC users wer assessed before and after a single, ad libitum, vaping session. Targeted social media advertising was used to collect a convenience, respondent-driven sample of EC users for for Arm 2. Subjects completed an online questionnaire that included measures of EC use and perceptions, tobacco use, HRQoL assessed using the brief version of World Health Organization Quality of Life, perceived health effects, and sociodemographic factors. A series of t-tests were conducted to assess for signifiant differences in Arm 1. Chi-square Test of Independence, Fisher’s exact test, Man-Whitney U, MANOVA, and ordinal logistic regressions were performed, as appropriate for the level of data, to determine associations between the outcome measures in Arm 2. Results: Arm 1. A single vaping session significantly affected lung function, placing the experimental group into the category of moderate chronic obstructive pulmonary disease. EC users also experienced increased central cardiovascular burden pre- to post-vaping. Microvascular and macrovascular function decreased after a single vaping session in EC users. There were no differences in FMD%, time to peak dilation, or FMD-AUC. Arm 2. Survey respondents were predominantly young adults, 67% of whom identified as former cigarette smokers. Former smokers reported perceiving EC use as less harmful than tobacco cigarettes, compared to 30% of current smokers. The majority of participants reported at least one adverse health effect attributable to EC use. WHOQOL-BREF scores were as follows: overall QOL, physical health, psychological well being, social relationships, and environment. The linear combination of QOL scores was significantly different based on smoking status. Conclusions: The results of this study demonstrate that EC users demonstrate poorer baseline pulmonary and vascular health parameters. Also, a single session of vaping causes decreases in pulmonary and cardiovascular function among regular EC users. Considering the critical role microcirculation plays in modulating vascular tone, these physiological responses may have long-term implications. In addition, the significant associations among EC use, HRQoL, and other health-risk behaviors provide valuable insights into lifestyle factors and conditions linked to EC use. These associations may also identify groups most likely in need of targeted interventions to reduce health-related inequalities.
