Exclusive Electronic Nicotine Delivery Systems Use Research Articles

Effects of Electronic Nicotine Delivery Systems Substitution on Body Weight Status: Protocol for a Systematic Review and Meta-Analysis.

Weight gain following smoking cessation is a well-documented concern, often attributed to the absence of nicotine's metabolic influence. The adoption of Electronic Nicotine Delivery Systems (ENDS) has been used to achieve smoking cessation, with claims of aiding weight control. However, existing reviews present conflicting conclusions on ENDS' impact on weight status, necessitating a rigorous evaluation. We aim to conduct a systematic review with meta-analysis to assess the actual impact of ENDS on weight status in individuals who have ceased or reduced conventional smoking. The primary goal is to provide clinicians with evidence-based insights into the potential effects of ENDS use as a smoking substitute on weight control. Adhering to PRISMA-P (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols) guidelines, our systematic review will analyze randomized and nonrandomized controlled trials, clinical trials (quasi-experimental), and prospective or retrospective cohort studies on the weight status effects of ENDS among individuals who have either quit or reduced smoking. Searches will include PubMed, Scopus, and Cochrane Library, covering the period from 2010 to January 2024. A gray literature search and supplementary searches will be performed. Data will be extracted independently by 2 reviewers and quality assessments will be conducted concurrently. Quality assessments will use Joanna Briggs Institute tools, 2020 version, along with bias assessments for internal validity and reporting bias based on the Catalogue of Bias. The included studies will be examined for any internal data reporting discrepancies by using Puljak's checklist. Meta-analysis and subgroup analyses (ie, general ENDS usage, ENDS use coupled with a reduction in smoking exceeding 50%, and exclusive ENDS use for achieving smoking cessation) are planned. Certainty of evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. The protocol has been registered in PROSPERO (CRD42023494974) and the entire systematic review is expected to be completed by April 2024. The main goal of this review is to retrieve all current human research studies investigating the influence of ENDS on weight management among individuals who have quit or reduced smoking. Furthermore, the review will assess the quality of these studies and examine potential biases to identify the most dependable evidence available. Dissemination strategies will include traditional journal publications, social media announcements, and a white paper. The latter, available for download and distributed at conferences, aims to reach a broad audience, including clinicians and ENDS users. The review will address the importance of informing health care professionals and patients about the current and robust evidence regarding the effects of transitioning to ENDS for smoking cessation on weight status. PROSPERO CRD42023494974; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=494974. PRR1-10.2196/56324.

Assessment of Electronic Nicotine Delivery Systems With Cigarette Use and Self-reported Wheezing in the US Adult Population

The prevalence of electronic nicotine delivery systems (ENDS) use has increased, leading to a concern about their respiratory health outcomes. It is unclear whether ENDS use increases the risk of wheezing, a common symptom of respiratory conditions. To provide an analysis of the longitudinal association between ENDS and cigarette use and self-reported wheezing among US adults. The US nationally representative Population Assessment of Tobacco and Health (PATH) Study was used. Longitudinal data for adults 18 years or older from wave 1 (2013-2014) to wave 5 (2018-2019) were analyzed. Data were analyzed from August 2021 to January 2023. The prevalence of self-reported wheezing (waves 2-5) was estimated for 6 strata of tobacco product use (never cigarette and noncurrent ENDS use, never cigarette and current ENDS use, current cigarette and noncurrent ENDS use, current cigarette and current ENDS use, former cigarette and noncurrent ENDS use, and former cigarette and current ENDS use). A generalized estimating equations framework evaluated the association between cigarette and ENDS use and self-reported wheezing at the subsequent wave. An interaction term between cigarette and ENDS use was added to estimate the association between joint cigarette and ENDS use categories and the association of ENDS within strata of cigarette use. The analytical sample consisted of 17 075 US adults with a mean (SD) age of 45.4 (17) years, of whom 8922 (51%) were female and 10 242 (66%) were Non-Hispanic White. When compared with never cigarette and noncurrent ENDS use, the greatest association in reporting wheezing was for current cigarette and current ENDS use (adjusted odds ratio [AOR], 3.26; 95% CI, 2.82-3.77), which was similar to current cigarette and noncurrent ENDS use (AOR, 3.20; 95% CI, 2.91-3.51) and substantially greater than former cigarette and current ENDS use (AOR, 1.94; 95% CI, 1.57-2.41). Associations were small and not statistically significant for the odds of self-reported wheezing among never cigarette and current ENDS use when compared with never cigarette and noncurrent ENDS use (AOR, 1.20; 95% CI, 0.83-1.72), and for odds of wheezing and current cigarette and current ENDS use when compared with current cigarette and noncurrent ENDS use (AOR, 1.02; 95% CI, 0.91-1.15). In this cohort study, exclusive ENDS use was not associated with an increase in the risk of self-reported wheezing. However, a small increase in risk between ENDS use and wheezing was reported by individuals who use cigarettes. This study adds to the literature about the potential health effects associated with ENDS use.

Socio-temporal contextual and community factors associated with daily exclusive ENDS use and dual use with tobacco cigarettes among adolescent vapers: an ecological momentary assessment study

BackgroundAdolescents who dual use ENDS with tobacco cigarettes are more likely to have an increased risk of developing dependence. Yet, little is understood about the factors driving dual use among adolescents. The current study sought to reveal the day-to-day socio-temporal contextual and community factors associated with adolescents’ use of electronic nicotine delivery systems (ENDS), and how these factors predict dual use with tobacco cigarettes.MethodsWe collected ecological momentary assessments (EMA) from a sample of 50 adolescent past two-week vapers (ages 14–17 years old) over 14 days. Daily EMA data were collected on ENDS and tobacco cigarette use, as well as a range of contextual (i.e., motivations to vape, location of vaping, who with when vaping) and community factors (i.e., exposure to peers vaping, to adults vaping, to ENDS advertising, to ENDS warning messages). Our primary analyses were multilevel regressions, accounting for daily observations nested within individuals (N = 700 observations).ResultsParticipants used ENDS exclusively on 44% of days and dual used ENDS and tobacco cigarettes on 8% of the days. Dual use days (versus exclusive ENDS use days) were associated with “vaping because tobacco use was prohibited” (OR = 34.65, p < .05). Also, dual use days (versus no use days) were associated with greater exposure to adults vaping (OR = 5.59, p < .05), peers vaping (OR = 7.48, p < .05), and (c) ENDS advertisements or promotions (OR = 2.12, p < .01), whereas exclusive use days (versus no use days) were only associated with greater exposure to peers vaping (OR = 2.58, p < .01).ConclusionsResults showed that exposure to peers and adults vaping and exposure to ENDS marketing were associated with same day dual use behaviors. And, that adolescents who dual used were motivated to use ENDS because they were easy to conceal. Findings support stricter regulation of ENDS marketing and for smoke-free air laws that include ENDS. In addition, these findings support prioritizing family- and school-based prevention programming that effectively communicates risk associated with ENDS use, including heightened risk of dual use and dependence. Such efforts can reduce the number of adolescents who use ENDS as well as the number who transition to tobacco cigarette use.

A Qualitative Analysis of the Experiences of People Who Resumed Smoking Following Exclusive Electronic Nicotine Delivery Systems Use.

For electronic nicotine delivery systems (ENDS) to reduce harms caused by smoking, people who smoke must be able to switch to exclusive ENDS use without subsequently returning to smoking. Identifying factors prompting a return to smoking among former exclusive ENDS users is crucial, yet few qualitative studies have probed experiences of this process. We conducted in-depth, semi-structured interviews with 20 people (seven indigenous Māori and 13 non-Māori) who smoked tobacco at least weekly, had smoked at least 100 cigarettes in their lifetime, and reported using ENDS to stop smoking cigarettes for at least 30 days (ideally, within the preceding 6 months). We explored their experiences of ENDS use, probed critical return-to-smoking settings and triggers, and analyzed strategies that could promote sustained smoking abstinence. We managed data using NVivo12 and used a reflexive thematic analysis approach to interpret the transcripts. We identified three themes that explained participants' experiences. ENDS performed a functional role by mimicking some aspects of smoking. Yet participants experienced ENDS as inauthentic and unsatisfying across physical, social, and affectual domains, including in the most common return-to-smoking situations. Furthermore, fewer constraints on ENDS usage led participants to feel they could perpetuate addiction and risk of harm. Return to smoking reflected two factors: ENDS' failure to replicate core smoking attributes that remained appealing, and the burden of self-regulation required when using ENDS. Understanding and informing people about the challenges involved in transitioning to ENDS, beyond obtaining sufficient nicotine, could help support informed ENDS use and may potentially prevent people returning to smoking. Our study extends our understanding of the satisfaction people seek when attempting to transition from smoking to exclusive ENDS use, and how ENDS' failure to replicate that satisfaction, in addition to uncertainty about ENDS-related risks, contributes to smoking resumption. Satisfaction went beyond nicotine delivery, and included affective experiences, maintenance of rituals, rewards, and social connections. Conceptualizing satisfaction more broadly could support a richer understanding of factors that prompt return to smoking. People might manage challenges more effectively if they understood these before attempting to switch from smoking to ENDS, and if they are advised to monitor and regulate their ENDS use. Educational resources and behavioral support could provide more guidance on these points.

Longitudinal Associations Between Exclusive and Dual Use of Electronic Nicotine Delivery Systems and Cigarettes and Self-Reported Incident Diagnosed Cardiovascular Disease Among Adults.

The cardiovascular health effects of electronic nicotine delivery systems (ENDS) use are not well characterized, making it difficult to assess ENDS as a potential harm reduction tool for adults who use cigarettes. Using waves 1-5 of the Population Assessment of Tobacco and Health Study (2013-2019), we analyzed the risk of self-reported incident diagnosed myocardial infarction (MI; 280 incident cases) and stroke (186 incident cases) associated with ENDS and/or cigarette use among adults aged 40 + using discrete time survival models. We employed a time-varying exposure lagged by one wave, defined as exclusive or dual established use of ENDS and/or cigarettes every day or some days, and controlled for demographics, clinical factors, and past smoking history. The analytic samples (MI = 11 031; stroke = 11 076) were predominantly female and non-Hispanic White with a mean age of 58 years. At baseline, 14.2% of respondents exclusively smoked cigarettes, 0.6% exclusively used ENDS, and 1.0% used both products. Incident MI and stroke were rare during follow-up (< 1% at each wave). Compared to no cigarette or ENDS use, exclusive cigarette use increased the risk of MI (aHR 1.99, 95% CI = 1.40-2.84) and stroke (aHR 2.26, 95% CI = 1.51-3.39), while exclusive ENDS use (MI: aHR 0.61, 95% CI = 0.12-3.04; stroke: aHR 1.74, 95% CI = 0.55-5.49) and dual use (MI: aHR 1.84, 95% CI = 0.64-5.30; stroke: aHR 1.12, 95% CI = 0.33-3.79) were not significantly associated with the risk of either outcome. Compared to non-use, exclusive cigarette use was associated with an increased risk of self-reported incident diagnosed cardiovascular disease over a 5-year period, while ENDS use was not associated with a statistically significant increase in the outcomes. Existing literature on the health effects of ENDS use has important limitations, including potential reverse causation and improper control for cigarette smoking. We accounted for these issues by using a prospective design and adjusting for current and former smoking status and cigarette pack-years. In this context, we did not find that ENDS use was associated with a statistically significant increase in self-reported incident diagnosed myocardial infarction or stroke over a 5-year period. While more studies are needed, this analysis provides an important foundation and key methodological considerations for future research on the health effects of ENDS use.

Changes in Biomarkers of Tobacco Exposure among Cigarette Smokers Transitioning to ENDS Use: The Population Assessment of Tobacco and Health Study, 2013-2015.

Limited data are available for how biomarkers of tobacco exposure (BOE) change when cigarette smokers transition to using electronic nicotine delivery systems (ENDS). Using biomarker data from Waves 1 (2013–2014) and 2 (2014–2015) of the PATH Study, we examined how mean BOE concentrations, including metabolites of nicotine, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC) and metals, changed when 2475 adult smokers transitioned to using ENDS or quit tobacco products. Exclusive smokers who transitioned to dual use had a significant decrease in NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), but not nicotine metabolites, most PAHs, metals, or VOCs. Exclusive smokers who became dual users had significant reductions in total nicotine equivalents, NNAL, and 2CyEMA (acrylonitrile metabolite), but only in those who reduced cigarettes per day (CPD) by >=50%. Smokers who transitioned to exclusive ENDS use had significant reductions in most TSNAs, PAHs, and VOCs; however, nicotine metabolites did not decrease in dual users who became exclusive ENDS users. Smokers who quit tobacco use had significant decreases in nicotine metabolites, all TSNAs, most PAHs, and most VOCs. Cigarette smokers who became dual users did not experience significant reductions in most BOEs. Reductions were impacted by changes in CPD. However, transitioning from smoking to no tobacco or exclusive ENDS use was associated with reduced exposure to most BOEs measured. Future analyses could incorporate additional waves of PATH data and examine changes in biomarker exposure by ENDS device type and CPD.

"When I Don't Have a Cigarette It's Helpful, but It Really Don't Satisfy:" Qualitative Study of Electronic Nicotine Delivery Systems (ENDS) Use among Low-Income Smokers.

Background: Little is known about the use of electronic nicotine delivery systems (ENDS) among low-income adult cigarette smokers, who experience severe tobacco-related health disparities. Methods: This study conducted interviews to examine experiences and perceptions associated with ENDS use among predominantly low-income adult smokers (n = 30; mean age 30.2 ± 12.9; 60% male, 46.7% African American, 30% white, 10% more than one race; 76.7% annual household income ≤USD 24,000). Interviews were transcribed verbatim and coded in NVivo 11. Results: Overall, participants reported complementing rather than substituting their smoking with ENDS use (e.g., using ENDS only when smoking is not allowed). Predominant reasons for vaping were convenience, smoking reduction/cessation, stress management, social acceptability, lower long-term costs than smoking, and appealing flavors. Common reasons for not switching to exclusive vaping were that ENDS did not satisfy cigarette cravings and concerns about ENDS health effects. Participants indicated higher likelihood of switching to exclusive ENDS use if the products were more affordable, perceived as substantially less harmful, tasted and felt more like smoking a cigarette, and more effective for reducing cravings. Conclusions: Continued research is needed to maximize any harm reduction potential of ENDS and ensure that these products do not contribute to worsening health disparities.

Trends in Exclusive, Dual and Polytobacco Use among U.S. Adults, 2014-2019: Results from Two Nationally Representative Surveys.

Although increases in the variety of tobacco products available to consumers have led to investigations of dual/polytobacco use patterns, few studies have documented trends in these patterns over time. We used data from the 2014/2015 and 2018/2019 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) and the 2015–2019 National Health Interview Survey (NHIS) to estimate trends in the following use patterns: exclusive use of cigarettes, electronic nicotine delivery systems (ENDS), other combustibles (cigars/cigarillos/little filtered cigars and traditional pipes/hookah), and smokeless tobacco (four categories); dual use (two product groups) of each product group with cigarettes (three categories); polyuse with cigarettes (all four product groups; one category); and dual/polyuse without cigarettes (one category). We estimated trends in product use patterns overall and by age, sex, and race/ethnicity using two-sample tests for differences in linear proportions. From 2014/2015 to 2018/2019, exclusive ENDS use increased, whereas cigarettes and ENDS dual use decreased. Furthermore, polyuse with cigarettes decreased, whereas dual/polyuse without cigarettes increased, with trends varying by age, sex, and race/ethnicity. Our findings suggest that patterns of dual/polyuse with and without cigarettes have changed in recent years, indicating the need for further surveillance of concurrent tobacco product use patterns.

Sociodemographic Patterns of Exclusive and Dual Use of ENDS and Menthol/Non-Menthol Cigarettes among US Youth (Ages 15-17) Using Two Nationally Representative Surveys (2013-2017).

The use of electronic nicotine delivery systems (ENDS) among youth in the United States has increased rapidly in the past decade. Simultaneously, while youth cigarette smoking has declined considerably, youth are still more likely to use menthol cigarettes than any other age group. We used nationally representative data on 15–17-year-olds from the Population Assessment of Tobacco and Health (PATH) Study and the National Youth Tobacco Survey (NYTS) (2013–2017) to better understand current cigarette (by menthol flavoring) and ENDS use in the US. We calculated weighted population prevalence estimates across years for multiple patterns of current cigarette and ENDS use (i.e., exclusive menthol cigarette, exclusive non-menthol cigarette, exclusive ENDS, dual ENDS and menthol cigarette, and dual ENDS and non-menthol cigarette) by sex, race/ethnicity, parental education level, household income, and homeownership. Overall, both exclusive menthol and non-menthol cigarette use declined from 2013–2017. Exclusive ENDS use increased, particularly among youth who were non-Hispanic White or had a higher socioeconomic status (measured by parental education, household income, and homeownership). Dual use of ENDS with either menthol or non-menthol cigarettes did not change significantly. Monitoring changes in these sociodemographic patterns will help inform future youth tobacco prevention strategies.

Electronic Nicotine Delivery Systems (ENDS) Use and Pregnancy I: ENDS Use Behavior During Pregnancy.

This review examines Electronic Nicotine Delivery Systems (ENDS) use behavior during pregnancy, including the prevalence of and transitions in use during pregnancy. Twenty-two papers addressed the prevalence of and/or transitions in ENDS use during pregnancy. Findings show a complex landscape of ENDS use. A minority (0.4%-7.0%) of pregnant persons use ENDS; most commonly this occurs in the form of dual use (ENDS and combustible cigarettes (CC); 75%). Many pregnant persons report using ENDS because they perceive them to be a lower-risk alternative and/or potential cessation aide for CC smoking. However, while a subset of those who use ENDS do quit all tobacco product use during pregnancy, only a small proportion switch from exclusive CC smoking to exclusive ENDS use. ENDS are a somewhat new addition to the tobacco product landscape. The perception of ENDS as a lower-risk alternative may contribute to ENDS use in pregnancy. There is insufficient evidence to support the notion that ENDS facilities the cessation of tobacco product use during pregnancy.

Use of electronic nicotine delivery systems (ENDS) among U.S. women of reproductive age: Prevalence, reported reasons for use, and toxin exposure

Given the rapidly expanding marketplace for Electronic Nicotine Delivery Systems (ENDS), it is important to monitor patterns of use, particularly among vulnerable populations. This study examined ENDS prevalence, reasons for use (i.e., to help quit smoking and for appealing flavors), and toxin exposure among U.S. women of reproductive age using data from the Population Assessment of Tobacco and Health (PATH) Study (2013–17). Exclusive ENDS users, dual users of ENDS and cigarettes, and exclusive cigarette smokers were compared within and between pregnant and not-pregnant women. Among pregnant women, prevalence of exclusive ENDS and dual use was similar (0.8%; 95%CI = 0.4–1.2% vs. 1.4%; 95%CI = 0.9–2.0%, respectively), but exclusive ENDS use was less prevalent than dual use among not-pregnant women (1.1%; 95%CI = 0.9–1.4% vs. 3.7%; 95%CI = 3.3–4.0%, respectively). Most women reported ENDs were used to help quit smoking (66.5–90.0%) and for appealing flavors (57.6–87.4%), and endorsement rates did not differ by use pattern or pregnancy status. Except for metals, toxin exposure was substantially lower for exclusive ENDS users relative to dual users and exclusive cigarette smokers regardless of pregnancy status. Pregnant and not-pregnant U.S. women regularly report using ENDS for help with quitting smoking and for appealing flavors. Although no type or pattern of tobacco/nicotine use is safe, especially during pregnancy, using ENDS exclusively is consistent with lower overall toxin exposure for pregnant and not-pregnant women. This study advances understanding of ENDS use and toxin exposure in women of reproductive age, a population highly vulnerable to the effects of nicotine/tobacco consumption.

Sociodemographic Patterns of Exclusive, Dual, and Polytobacco Use Among U.S. High School Students: A Comparison of Three Nationally Representative Surveys

PurposeThis study examines sociodemographic patterns of exclusive/dual/polytobacco use among U.S. high school students using multiple national surveys. MethodsUsing three national youth surveys (Population Assessment of Tobacco and Health [PATH] Wave 4 [2016–2017], 2017 Youth Risk Behavior Survey, and 2017 National Youth Tobacco Survey), we classified tobacco products into four groups: (1) electronic nicotine delivery systems (ENDS), (2) conventional cigarettes (CCs), (3) other combustible tobacco products, and (4) smokeless tobacco products. We created 16 categories of non/exclusive/dual/polytobacco use within the past 30 days using the four product groups and calculated weighted population prevalence by sex and race/ethnicity (all surveys) and parental education and income (PATH), based on variable availability. ResultsThe results from 9,331, 12,407, and 9,699 high school students in PATH, Youth Risk Behavior Survey, and National Youth Tobacco Survey, respectively, largely agreed and pointed to similar conclusions. ENDS was the most prevalent exclusive use product (3.8%–5.2% across surveys), with CCs falling to second or third (1.2%–2.0% across surveys). By sex, exclusive, dual, and poly smokeless tobacco product use were more common for males, whereas exclusive CC use was more common for females. By race/ethnicity, non-Hispanic Whites had a higher prevalence of exclusive ENDS use and ENDS/CC dual use than non-Hispanic Blacks. As income and parental education levels increased from low to high, the prevalence of exclusive CC use decreased, whereas the prevalence of exclusive ENDS use increased. ConclusionUnderstanding sociodemographic patterns of tobacco use can help identify groups who may be at greater risk for tobacco-related health outcomes.

What Motivates Smokers to Switch to ENDS? A Qualitative Study of Perceptions and Use.

Switching completely from cigarettes to electronic nicotine delivery systems (ENDS) may reduce health risks for addicted smokers. This paper provides information about perceptions and other factors that may influence smokers’ ENDS use and substitution for cigarettes. We conducted 12 online focus groups (N = 61) among smokers who had never tried using ENDS (Never Users, N = 11), currently used both cigarettes and ENDS (Dual Users, N = 21), used but discontinued ENDS (Rejectors, N = 14), and switched completely to ENDS use (Switchers, N = 15). Thematic analysis was used to interpret the transcripts. Participants described initial interest in trying ENDS in hopes of quitting smoking and because of convenience (i.e., due to rules, regulations, or social norms). Risk perceptions and higher prices relative to cigarettes were reported as disadvantages of ENDS that discouraged initiation. Dual Users and Rejectors reported product problems (e.g., products breaking) and dissatisfaction (i.e., inability to satisfy cravings for cigarettes) as factors that lowered their substitutability for cigarettes or led to discontinuing ENDS use. Switchers indicated that satisfaction, lack of product problems, and perceived safety facilitated successfully switching from cigarette smoking to exclusive ENDS use. However, Switchers reported trying many products before they found ones that satisfied their needs. We recommend that policymakers consider the potential impact of tobacco control policies on smokers’ motivation and ability to switch completely from cigarettes to ENDS.

Metabolomic Analysis Identified Reduced Levels of Xenobiotics, Oxidative Stress, and Improved Vitamin Metabolism in Smokers Switched to Vuse Electronic Nicotine Delivery System.

IntroductionSwitching to noncombustible tobacco products presents an opportunity for cigarette smokers to potentially reduce the health risks associated with smoking. Electronic Nicotine Delivery Systems (ENDS) are one such product because the vapor produced from ENDS contains far fewer toxicants than cigarette smoke. To investigate the biochemical effects of switching from smoking to an ENDS, we assessed global metabolomic profiles of smokers in a 7-day confinement clinical study.MethodsIn the first 2 days of this clinical study, the subjects used their usual brand of cigarettes and then switched to exclusive ENDS ad libitum use for 5 days. Urine and plasma samples were collected at baseline and 5 days after switching. The samples were analyzed using a mass spectrometry-based metabolomic platform.ResultsRandom forest analyses of urine and plasma metabolomic data revealed excellent predictive accuracy (>97%) of a 30-metabolite signature that can differentiate smokers from 5-day ENDS switchers. In these signatures, most biomarkers are nicotine-derived metabolites or xenobiotics. They were significantly reduced in urine and plasma, suggesting a decreased xenobiotic load on subjects. Our results also show significantly decreased levels of plasma glutathione metabolites after switching, which suggests reduced levels of oxidative stress. In addition, increased urinary and plasma levels of vitamins and antioxidants were identified, suggesting enhanced bioavailability due to discontinuation of cigarette smoking and switching to Vuse ENDS use.ConclusionsOur results suggest reduced toxicant exposure, reduced oxidative stress, and potential beneficial changes in vitamin metabolism within 5 days in smokers switching to Vuse ENDS.ImplicationsSwitching from smoking to exclusive ENDS use in clinical confinement settings results in significant reduction of nicotine metabolites and other cigarette-related xenobiotics in urine and plasma of subjects. Significantly decreased oxidative stress-related metabolites and increased urinary and plasma levels of vitamin metabolites and antioxidants in 5-day short-term ENDS switchers suggest less toxic physiological environment for consumers of ENDS products and potential health benefits if such changes persist.