Association between the use of electronic cigarettes and myocardial infarction in U.S. adults.

BACKGROUND: Compared with conventional cigarettes, electronic cigarettes are less harmful in some studies. However, recent research may indicate the opposite. This study aimed to determine whether e-cigarette use is related to myocardial health in adults in the U.S. METHODS: This study used data from the 2020 Behavioral Risk Factor Surveillance System (BRFSS), a cross-sectional survey of adult US residents aged 18 years or older. We examined whether e-cigarette use was related to myocardial infarction byapplying a logistic regression model to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The final analytical sample included 198,530 adults in the U.S. Logistic regression indicated that U.S. adults who reported being former and some days of e-cigarette use had 23% and 52% greater odds of ever having an MI, respectively, than did those who reported never using e-cigarettes (OR = 1.23, 95% CI 1.08-1.40, p = 0.001; OR = 1.52, 95% CI 1.10-2.09, p = 0.010). CONCLUSIONS: The results suggest that former and someday users of e-cigarettes probably have increased odds of myocardial infarction in adults in the U.S. Further research is needed, including long-term follow-up studies on e-cigarettes, since it is still unknown whether they should be discouraged.

E-Cigarette Characteristics and Cigarette Cessation Among Adults Who Use E-Cigarettes.

Importance: Population-level health outcomes associated with e-cigarettes depend in part on the association between e-cigarettes and combustible cigarette cessation. The US Food and Drug Administration has authority to regulate e-cigarette characteristics, including flavor and device type. Objective: To investigate whether e-cigarette characteristics are associated with cigarette cessation behaviors among adults in the US population who use e-cigarettes. Design, Setting, and Participants: This cohort study was conducted using longitudinal data collected in 2014 to 2021 by the Population Assessment of Tobacco and Health Study, a population-based, US nationally representative study. Participants were sampled from the civilian noninstitutionalized population using a 4-staged, stratified sampling design. Data were weighted and analyzed from 1985 adults ages 21 or older who smoked cigarettes daily and had used e-cigarettes in the past 30 days. Data were analyzed in May 2021 to May 2024. Exposures: The following e-cigarette characteristics were assessed: use frequency (daily and nondaily), flavor type (tobacco, menthol or mint, sweet, and combination), device type (disposable, cartridge, and tank), and year of data collection as a proxy for the evolving e-cigarette marketplace. Main Outcomes and Measures: The following cigarette cessation behaviors were assessed: making a cigarette quit attempt, cigarette cessation among individuals who made a quit attempt, and overall cigarette discontinuation regardless of quit attempts. Associations were evaluated between e-cigarette characteristics (assessed at baseline in 1 approach and assessed at follow-up in another approach) and cigarette cessation outcomes, controlling for demographic, cigarette smoking, and other e-cigarette use characteristics. Results: The study sample consisted of 1985 participants representing adults in the population (mean age, 40.0 years [95% CI, 39.2-40.9 years]; 49.4% [95% CI, 46.3%-52.6%] male; 11.4% [95% CI, 9.6%-13.4%] Black, 80.7% [95% CI, 77.8%-83.3%] White, and 8.0% [95% CI, 6.3%-10.0%] other race; 9.2% [95% CI, 7.5%-11.2%] Hispanic). Daily vs nondaily e-cigarette use was associated with greater overall cigarette discontinuation rates (12.8% [95% CI, 9.1%-17.7%] vs 6.1% [95% CI, 4.8%-7.7%]; adjusted odds ratio [aOR], 2.26 [95% CI, 1.34-3.81]), and use of e-cigarettes in 2019 to 2021 vs 2014-2015 to 2015-2016 was also associated with greater overall cigarette discontinuation rates (12.0% [95% CI, 8.8%-16.0%] vs 5.3% [95% CI, 2.9%-9.3%]; aOR, 2.75 [95% CI, 1.13-6.67]). Use of menthol or mint vs tobacco flavor e-cigarettes was associated with greater overall cigarette discontinuation rates (9.2% [95% CI, 6.6%-12.8%] vs 4.7% [95% CI, 3.0%-7.1%]; aOR, 2.63 [95% CI, 1.32-5.27]) only when assessing e-cigarette use at baseline. E-cigarette device type was not associated with cigarette discontinuation rates in adjusted analyses. Conclusions and Relevance: In this study, daily e-cigarette use and use of e-cigarettes in 2019 to 2021 were consistently associated with greater cigarette discontinuation rates. These findings suggest that research focused on e-cigarettes marketed in recent years is needed to inform product regulation and public health policy decisions.

E-Cigarette Nicotine Delivery Among Young Adults by Nicotine Form, Concentration, and Flavor: A Crossover Randomized Clinical Trial.

Importance: Concerns have been raised about the abuse liability of modern e-cigarettes that use acidic additives to form nicotine salts, making the inhalation of nicotine smoother than freebase nicotine. Objective: To examine the effects of nicotine form and concentration and e-liquid flavor on subjective effects ratings, vaping behavior, and nicotine uptake among young adults who use e-cigarettes. Design, Setting, and Participants: In this single-blind, within-participant, crossover randomized clinical trial, a convenience sample of young adults aged 21 to 25 years who currently used e-cigarettes was recruited from December 2021 to August 2023, for in-person research laboratory visits in Columbus, Ohio. Interventions: Participants completed up to 9 vaping sessions, starting with their usual e-cigarette brand in the first session followed by 1 of 8 laboratory-prepared e-liquids in a randomly assigned order in each subsequent session. Prepared e-liquids varied by nicotine form (salt-based vs freebase), nicotine concentration (5% vs 1% weight per weight), and flavor (menthol vs tobacco). Each session included a 5-minute, 10-puff standardized vaping period followed by 30 minutes of ad libitum vaping. Main Outcomes and Measures: At 4 time points (0, 5, 10, and 35 minutes) during each vaping session, plasma samples were collected for assessing nicotine uptake, and self-reports of urges, craving, and withdrawal were collected via questionnaires. Positive subjective effects were self-reported after 35 minutes of vaping using a visual analog scale; urges and cravings were reported using the Questionnaire of Smoking Urges (QSU). Puff topography data were collected throughout each vaping session. Results: Seventy-two participants (mean [SD] age, 22.4 [1.4] years; 42 [58.3%] female) who sampled at least 1 laboratory-prepared e-liquid composed the analytic sample. Salt-based (vs freebase) nicotine e-liquids increased nicotine intake, with 5% salt-based e-liquids delivering the highest mean plasma levels of nicotine (11.2 ng/mL [95% CI, 9.3-13.2 ng/mL] at 5 minutes; 17.2 ng/mL [95% CI, 14.3-20.1 ng/mL] at 35 minutes) irrespective of flavors. Higher positive subjective effect ratings (eg, for liking) were received by salt-based (42.8; 95% CI, 39.4-46.1) vs freebase (32.0; 95% CI, 28.6-35.3) nicotine, 1% (43.4; 95% CI, 40.2-46.6) vs 5% (31.2; 95% CI, 27.7-34.6) nicotine, and menthol-flavored (43.2; 95% CI, 39.7-46.7) vs tobacco-flavored (31.5; 95% CI, 28.4-34.7) e-liquids. Salt-based and 1% but not menthol-flavored nicotine elicited more intense puffing (eg, 25% [95% CI, 12%-40%] more total puffs for nicotine salts vs freebase). All study e-liquids reduced urges and cravings, with 5% vs 1% nicotine being more effective (mean [SE] QSU-Desire score at 35 minutes, 15.4 [0.5] vs 16.7 [0.5]). Conclusions and Relevance: In this crossover randomized clinical trial among young adult e-cigarette users, salt-based (vs freebase) nicotine e-liquids increased nicotine intake and yielded more positive subjective effects ratings and intense puffing behaviors, suggesting higher abuse potential. Restricting the level of acidic additives and menthol flavoring may reduce the addictiveness of e-cigarettes. Trial Registration: ClinicalTrials.gov Identifier: NCT05458895.

Longitudinal associations between exclusive, dual and polytobacco use and respiratory illness among youth.

BACKGROUND: The health consequences of polytobacco use are not well understood. We evaluated prospective associations between exclusive, dual, and polytobacco use and diagnosed bronchitis, pneumonia, or chronic cough among US youth. METHODS: Data came from Waves 1-5 of the Population Assessment of Tobacco and Health Study. We categorized time-varying past 30-day tobacco use into seven categories: (1) non-current use; exclusive use of 2) cigarettes, 3) e-cigarettes, and 4) other combustible products (OC; pipes, hookah, and cigars); dual use of 5) e-cigarettes + cigarettes or e-cigarettes + OC, and 6) cigarettes + OC; and 7) polyuse of all three products. The outcome was parent-reported diagnosis of bronchitis, pneumonia, or chronic cough among youth. We conducted weighted multilevel Poisson models (person n = 17,517, 43,290 observations) to examine the longitudinal exposure-outcome relationship, adjusting for covariates: sex, age, race and ethnicity, parental education, body mass index, secondhand smoke exposure, and household use of combustible products. RESULTS: Compared to nonuse, exclusive cigarette use (Risk Ratio (RR) = 1.83, 95% CI 1.25-2.68), exclusive e-cigarette use (RR = 1.53, 95% CI 1.08-2.15), combustible product + e-cigarette dual use (RR = 1.90, 95% CI 1.18-3.04), cigarettes + OC dual use (RR = 1.96, 95% CI 1.11-3.48), and polytobacco use (RR = 3.06 95% CI 1.67-5.63) were associated with a higher risk of bronchitis, pneumonia, or chronic cough. In additional analyses, we found that the risk ratio for polytobacco use was higher compared to exclusive e-cigarette use (RR 2.01 CI 95% 1.02-3.95), but not higher compared to exclusive cigarette use (RR 1.67 CI 95% 0.85-3.28). CONCLUSION: We found that exclusive, dual, and poly tobacco use were all associated with higher risk of bronchitis, pneumonia, or chronic cough compared to non-current use.

Direct health implications of e-cigarette use: a systematic scoping review with evidence assessment.

Background: E-cigarettes are often marketed as a less harmful alternative to traditional tobacco cigarettes. Despite their popularity, the evidence regarding their effects on human health remains unclear and is filled with complexities. Objectives: This systematic review aims to elucidate the direct effects of electronic cigarette use on human health, carefully distinguishing between the specific characteristics of the populations studied. Methodology: Adhering to the PRISMA guidelines, we conducted a comprehensive search in PubMed/Medline, Web of Science, Scopus, and Google Scholar databases without date restrictions, including articles in both Spanish and English. This approach enabled the identification and analysis of primary studies to understand the direct effect of electronic cigarettes on human health. Results: A total of 33 studies were included that evaluated cardiovascular, pulmonary, renal, weight and fertility effects. Only five studies analyzed e-cigarettes in healthy populations and seven studies compared healthy individuals against smokers. The effects evaluated on smokers or former tobacco smokers were apparently positive, however, among healthy individuals, increased heart rate, mean arterial pressure, oxidative stress, alteration of respiratory epithelial cells and increased airflow resistance were found. Conclusion: Smokers or former smokers who switch to e-cigarettes may reduce their exposure to carcinogens and lower their risk of developing severe health issues associated with conventional smoking. However, in healthy individuals who have never smoked traditional cigarettes, the use of e-cigarettes introduces several cardiovascular and respiratory adverse effects. These findings suggest that while e-cigarettes can be a strategic harm reduction tool for smokers, they are not a safe option for non-smokers.

Increased e-cigarette use prevalence is associated with decreased smoking prevalence among US adults.

BACKGROUND: If US adults who smoke cigarettes are switching to e-cigarettes, the effect may be observable at the population level: smoking prevalence should decline as e-cigarette prevalence increases, especially in sub-populations with highest e-cigarette use. This study aimed to assess such effects in recent nationally-representative data. METHODS: We updated a prior analysis with the latest available National Health Interview Survey data through 2022. Data were cross-sectional estimates of the yearly prevalence of smoking and e-cigarette use, respectively, among US adults and among specific age, race/ethnicity, and sex subpopulations. Non-linear models were fitted to observed smoking prevalence in the pre-e-cigarette era, with a range of 'cut-off' years explored (i.e., between when e-cigarettes were first introduced to when they became widely available). These trends were projected forward to predict what smoking prevalence would have been if pre-e-cigarette era trends had continued uninterrupted. The difference between actual and predicted smoking prevalence ('discrepancy') was compared to e-cigarette use prevalence in each year in the e-cigarette era to investigate whether the observed decline in smoking was statistically associated with e-cigarette use. RESULTS: Observed smoking prevalence in the e-cigarette era was significantly lower than expected based on pre-e-cigarette era trends; these discrepancies in smoking prevalence grew as e-cigarette use prevalence increased, and were larger in subpopulations with higher e-cigarette use, especially younger adults aged 18-34. Results were robust to sensitivity tests varying the analysis design. CONCLUSIONS: Population-level data continue to suggest that smoking prevalence has declined at an accelerated rate in the last decade in ways correlated with increased uptake of e-cigarette use.

Secondhand Nicotine Absorption From E-Cigarette Vapor vs Tobacco Smoke in Children.

Importance: With the prevalence of e-cigarette use (vaping) increasing worldwide, there are concerns about children's exposure to secondhand vapor. Objective: To compare nicotine absorption among children who are (1) exposed to secondhand tobacco smoke only or (2) exposed to secondhand vapor only with (3) those exposed to neither. Design, Setting, and Participants: The US Continuous National Health and Nutrition Examination Survey (NHANES) is a repeat cross-sectional survey. Participants are interviewed in their homes and, several days after, visit a mobile examination center to provide biological specimens. This study uses data from a nationally representative sample of US households from 2017 to 2020. Participants were children aged 3 to 11 years with serum cotinine levels incompatible with current firsthand nicotine use (ie, <15 µg/L). The final analysis was conducted on January 9, 2024. Exposures: Reported exposure to secondhand smoke or vapor indoors in the past 7 days (only secondhand smoke, only secondhand vapor, or neither). Covariates included age, sex, ethnicity, family income, body weight, and height. Main Outcomes and Measures: The primary outcome was serum cotinine concentration, an objective biomarker of nicotine absorption. Geometric mean cotinine levels and 95% CIs were calculated using log-normal tobit regression, accounting for the complex survey design and weights. Results: The mean (SD) age of the 1777 children surveyed was 7.4 (2.6) years, 882 (49.6%) were female, and 531 (29.9%) had family incomes below the poverty level. Nicotine absorption, as indexed by serum cotinine level, was highest among children only exposed to secondhand smoke (0.494 µg/L µg/L; 95% CI, 0.386-0.633 µg/L), followed by those exposed only to secondhand vapor (0.081 µg/L; 95% CI, 0.048-0.137 µg/L), equating to 83.6% (95% CI, 71.5%-90.5%; P < .001) lower nicotine absorption. Among children with no reported secondhand exposure, the geometric mean cotinine level was 0.016 µg/L (95% CI, 0.013-0.021 µg/L), or 96.7% (95% CI, 95.6%-97.6%; P < .001) lower than for those with exposure to secondhand smoke. Results were similar after covariate adjustment. Conclusions and Relevance: In this cross-sectional study of US children, nicotine absorption was much lower in children who were exposed to secondhand vapor vs secondhand smoke, but higher than in those exposed to neither. These findings suggest that switching from smoking to vaping indoors may substantially reduce, but not eliminate, children's secondhand exposure to nicotine and other noxious substances.

Trends in long term vaping among adults in England, 2013-23: population based study.

OBJECTIVE: To examine trends in long term (>6 months) vaping among adults in England. DESIGN: Population based study. SETTING: England. PARTICIPANTS: 179 725 adults (≥18 years) surveyed between October 2013 and October 2023. MAIN OUTCOME MEASURES: Time trends in prevalence of long term vaping using logistic regression, overall and by vaping frequency (daily or non-daily), and main type of device used (disposable, refillable, or pod). RESULTS: The proportion of adults reporting long term vaping increased non-linearly, from 1.3% (95% confidence interval 1.1% to 1.5%) in October 2013 to 10.0% (9.2% to 10.9%) in October 2023, with a particularly pronounced rise from 2021. This rise included an increase in long term daily vaping, from 0.6% (0.5% to 0.8%) to 6.7% (6.0% to 7.4%). Absolute increases in long term vaping were larger among people with a history of regular smoking (current smokers: 4.8% (4.0% to 5.8%) to 23.1% (20.4% to 25.9%); recent former smokers: 5.7% (3.4% to 9.2%) to 36.1% (27.6% to 45.4%); long term former smokers: 1.4% (1.0% to 1.9%) to 16.2% (14.2% to 18.4%)), but an increase also occurred among people who had never regularly smoked (0.1% (0.0% to 0.2%) to 3.0% (2.3% to 3.8%)). Growth was also more pronounced in young adults (eg, reaching 22.7% (19.2% to 26.5%) of 18 year olds v 4.3% (3.6% to 5.2%) of 65 year olds), including among those who had never regularly smoked (reaching 16.1% (11.1% to 22.7%) of 18 year olds v 0.3% (0.1% to 0.6%) of 65 year olds). Between October 2013 and March 2021, most long term vapers mainly or exclusively used refillable electronic cigarettes (2.5% to 3.3% of adults) and few (0.1% of adults) used disposable devices. However, prevalence of long term vaping using disposable devices subsequently rose rapidly, and by October 2023 similar proportions of adults mainly or exclusively used disposable and refillable devices (4.9% (4.2% to 5.7%) and 4.6% (4.0% to 5.3%), respectively). CONCLUSIONS: The prevalence of long term vaping increased substantially among adults in England during 2013-23. Much of this increase occurred from 2021, coinciding with the rise in popularity of disposable e-cigarettes. Half of long term vapers now mainly or exclusively use disposable devices. The growth was concentrated among people with a history of regular smoking, but an increase also occurred among people who never regularly smoked, especially young adults.

A decomposition analysis of sociodemographic factors and non-cigarette tobacco use as contributors to the change in smoking rates in South Africa between 2017/18 and 2021.

BACKGROUND: Trends data up to 2018 suggest that tobacco smoking was increasing in South Africa (SA), but only limited information is available on the impact of the COVID-19 pandemic on the current pattern of use of tobacco and nicotine products (TNPs). OBJECTIVES: To assess trends in sociodemographic patterns in the use of TNPs and the extent to which sociodemographic factors and non-cigarette tobacco use may explain possible changes in rates of TNP use between 2017/18 and 2021. METHODS: Data from three waves (2017, 2018 and 2021) of the South African Social Attitudes Survey (total N=8 140) were analysed. The sociodemographic correlates of current daily and non-daily use of factory-manufactured cigarettes (FMCs), roll-your-own (RYO) cigarettes, waterpipe/hubbly, electronic cigarettes (ECigs), snuff (a smokeless tobacco) and any combination of FMCs, RYO cigarettes and waterpipe/hubbly ('current smoking') in 2017/18 (pre-pandemic) were compared with those for 2021 (during the pandemic). Chi-square analyses and generalised linear models were used to compare the prevalence of TNP use between the two periods. A Blinda-Oaxaca decomposition analysis was also used to explore the roles of various sociodemographic factors, including any differences in the use of TNPs, that may explain any observed differences in smoking rates between 2017/18 and 2021. RESULTS: Current smoking increased significantly from 22.4% (95% confidence interval (CI) 20.4 - 24.5) in 2017/18 to 27.6% (95% CI 24.3 - 31.1) in 2021 (p=0.009). Smoking of FMCs did not change significantly overall between these two periods (20.1% v. 22.1%; p=0.240), except for a significant increase among those who self-identified as black African and a decrease among those who self-identified as coloured and those currently employed. However, the use of waterpipe/hubbly, ECigs, RYO cigarettes and snuff increased significantly. Women, individuals aged <35 years and black Africans had the largest increase in waterpipe/hubbly and ECig use. A decomposition analysis showed that increased waterpipe/hubbly and RYO use explained 52% and 15%, respectively, of the increase in smoking rates, while lower employment during 2021 compared with 2017/18 explained 15% of the increase in smoking rates during 2021. CONCLUSION: The use of all TNPs continued to increase in SA, particularly among women and unemployed people. These findings have policy and practice implications for addressing socioeconomic disparities in tobacco-related diseases.

E-Cigarette Use and Lung Cancer Screening Uptake.

This cross-sectional study examines e-cigarette use and lung cancer screening uptake among individuals in the US.

Prevalence, perception, and attitude regarding electronic cigarettes usage among young adults in Riyadh, Saudi Arabia. A cross-sectional study.

OBJECTIVES: To determine the prevalence of electronic cigarette (e-cigarette) usage among young adults in Riyadh, Saudi Arabia; their perceptions of its harm and legal age, and the reasons and factors influencing their use. METHODS: This cross-sectional study was carried out within the general community of Riyadh, Saudi Arabia, between December 2023 and April 2024. Participants aged 18-25 years were included. A self-administered online questionnaire was used to gather demographic data, perceptions, and attitudes toward e-cigarettes and reasons for their use. RESULTS: The majority of the 476 participants were female (n=378, 79.4%) and Saudi nationals (n=451, 94.7%). Current e-cigarette usage was 10.5% (n=50), being more prevalent among males (n=46, 46.9%) and non-Saudis (n=12, 48%). Respondents living alone (n=11, 34.4%) or with friends (n=4, 80%), those who perceived e-cigarettes as safer than cigarettes (n=38, 42.2%), or were unsure of age restrictions demonstrated high usage. Key motivators included flavors available, stress relief, and curiosity. CONCLUSION: Eelectronic cigarette use among Riyadh's youth was remarkable, especially among males. Reducing the e-cigarette usage prevalence in Saudi Arabia should be prioritized.

Unintended exposure to e-liquids and subsequent health outcomes among US youth and adults.

This study aimed to determine the prevalence and predictors of oral, ocular, or dermal e-liquid exposure and subsequent outcomes (becoming sick, going to the hospital) in the US. We examined survey data from the Population Assessment of Tobacco and Health Study Wave 5 (2018-2019). The analytic sample included US youth (aged 12-17 years), young adults (aged 18-24 years), and older adults (aged ≥ 25 years) who reported e-cigarette use in the past 12 months. We first determined the prevalence of self-reported e-liquid exposure (in the mouth, skin, or eyes), subsequently "becoming sick" from the exposure, and "going to the hospital" after the exposure. We also examined associations between these outcomes and the device type used (refillable tank /mod system, replaceable prefilled cartridges, disposable/ other device type). E-liquid exposure was reported by 25% of youth (aged 12-17 years), 25% of young adults (aged 18-24 years), and 19% of older adults (aged≥ 25 years). Among individuals reporting e-liquid exposure, subsequent sickness was reported by 10% of youth11% of young adults, and 14% of older adults, and "going to the hospital" was reported by 3.5% of youth, 2.7% of young adults, and 6.8% of older adults. Among young adults, the use of a refillable tank /mod system was associated with higher odds of e-liquid exposure (aOR = 2.2, 95% CI = 1.2, 4.1) than the use of other device types, including disposables. The findings suggest that, at a minimum, e-cigarettes/e-liquids may need warning labels that state the risks of e-liquid exposure and packaging regulations that promote device and bottle designs that minimize e-liquid spills.

Susceptibility to e-cigarette among high school students: a study based on the ecological model of health behavior.

Introduction: Youth e-cigarette (EC) use has rapidly increased in the last few years. It is crucial to identify the susceptible youth and prevent them from EC uptake. This study was conducted to investigate factors that affect youth susceptibility to EC use. Methods: This study employed a cross-sectional survey design, utilizing multi-center stratified cluster sampling method to select two junior high schools and two senior high schools in Shanghai, Guangzhou, and Chengdu. One-third of classes of each grade in the selected schools were involved in this survey. After obtaining the informed consent of parents, an anonymous and self-administered questionnaire was distributed to students. Questionnaire was designed based on the Ecological Models of Health Behavior. Associations between EC susceptibility and covariates were identified using multivariate logistic regression. Results: Among 2,270 students who had never vaped, 38.0% were susceptible to ECs. Logistic regression analysis identified factors on different levels affecting the susceptibility. Individual factors included senior high school students (OR = 1.34, 95% CI: 1.08-1.65), sensation seeker (OR = 1.11, 95%CI: 1.08-1.14), poor academic performance (OR = 1.24, 95% CI: 1.01-1.54), ever cigarette user (OR = 2.27, 95% CI: 1.29-4.01), unaware of the second-hand smoke from vaping (OR = 1.56, 95% CI: 1.25-1.96), agreeable with "I do not want to hang around vapers" (OR = 0.79, 95% CI: 0.64-0.97), agreeable with "ECs are more fashionable than cigarette" (OR = 2.50, 95% CI: 1.72-3.62) and favorable attitudes toward vaping (OR = 5.09, 95% CI: 3.78-6.85) were significantly associated with susceptibility to ECs. At interpersonal level, students who believe they would not be punished by parents for vaping increased susceptibility (OR = 1.27, 95% CI:1.01-1.59). At community level, exposure of EC advertising (OR = 1.81, 95% CI:1.46-2.25), exposure to hazard information (OR = 0.76, 95% CI: 0.59-0.97) and seeing vaping in daily life (OR = 2.11, 95% CI: 1.62-2.74), were statistically significantly associated with youth susceptibility to ECs. Conclusion: EC susceptibility was observed in a substantial proportion of adolescents who had never vaped, influenced by factors on different levels. This research underscores the urgent need for comprehensive intervention strategies to prevent the youth susceptibility to ECs.

Popularity of Zyn and other nicotine pouch brands among U.S. adolescents, young adults, and adults in 2021.

OBJECTIVE: This study identifies brands of nicotine pouches used in 2021, just before the surge in popularity of Zyn use. METHODS: We conducted a national, cross-sectional online survey of a general U.S. population (November to December 2021; N = 6131; age 13-40) via Qualtrics panels. Descriptive analyses and chi-squared tests (alpha = 0.05) were performed to assess ever and past-30-day use of nicotine pouch brands across adolescents (13-20), young adults (21-24), and adults (25-40), and to assess frequency of popular brands used among peers. RESULTS: The top brands ever used were Zyn (overall: 30.9%; adolescents: 31.9%; young adults: 33.2%; adults: 28.3%) and Lyft (overall: 28.8%; adolescents: 28.4%; young adults: 32.9%; adults: 26.3%), with no differences in ever-use by age group (p's > 0.095). The top brands used in the past-30-days were Zyn (overall: 26.4%; adolescents: 24.5%; young adults: 24.3%; adults: 30.0%) and Rush (overall: 24.2%; adolescents: 21.0%; young adults: 22.7%; adults: 28.6%). Adults (vs. adolescents, young adults) were more likely to report past-30-day use of Lyft (p = 0.004). Participants indicated Zyn (18.5%) and Lyft (18.2%) to be the most popular brands among peers. CONCLUSIONS: Even in 2021, Zyn was the most popular brand of nicotine pouches. Findings will help regulate and reduce impact of marketing of Zyn.

Use of ENDS devices and modifications to vape cannabis among adolescents and young adults who also vape nicotine.

BACKGROUND: Electronic nicotine delivery systems (ENDS) are the most used tobacco product among adolescents and young adults (AYAs) and are increasingly used to vape cannabis. It is unclear what vaping devices and ENDS modifications are used most frequently by AYAs who vape both nicotine and cannabis. METHODS: AYAs (aged 14-29) reporting ENDS use in the past 30 days were recruited via Qualtrics (N = 1,011). We conducted three multivariable logistic regression models examining differences in likelihood of: 1) vaping cannabis in the past 30 days; 2) mixing cannabis and nicotine liquids; and 3) using nicotine devices to vape cannabis; based on type of vaping device used most often, controlling for age, socio-economic status, gender, race, frequency of ENDS use, and other cannabis use. RESULTS: 40 % (n = 405) of AYAs reported vaping both nicotine and cannabis in the past 30 days. AYAs who used vape pens most often were more likely to have vaped cannabis concentrates in the past 30 days compared to individuals using disposable vapes (aOR = 2.72, 95 %CI = 1.75-4.21, p < 0.001). AYAs who used open systems most often (i.e., vape pens, mods, or e-hookah) were more likely than individuals using closed systems (i.e., disposable vapes, rechargeable pods or cigalikes) to combine nicotine and cannabis e-liquids (aOR = 2.03, 95 %CI = 1.43-2.89, p < 0.001) or use a nicotine device to vape cannabis (aOR = 1.66, 95 %CI = 1.17-2.34, p = 0.005). IMPLICATIONS: Co-use of cannabis and nicotine via similar devices, particularly vape pens and other open-systems, warrants collaborative regulatory efforts to mitigate co-use of both substances, with a particular need for increased regulation of cannabis vaping products.

Measures of youth e-cigarette use: strengths, weaknesses and recommendations.

This perspective discusses how to best define "e-cigarette use" among youth in a way that is relevant to individual and human health. Commonly-used definitions of youth e-cigarette use have been adapted from measures validated for tobacco cigarette smoking among adults, but may not carry the same meaning for a different product (with a much lower risk profile and very different patterns of use) and a different population (whose use is more often transient and experimental, rather than frequent and persistent). We discuss strengths and weaknesses of different definitions, and recommend improvements in defining youth e-cigarette use. We find that current literature employs a range of definitions of e-cigarette use, from lifetime use ("even a puff") to daily use. More lenient measures capture more potentially at-risk youth, but much of this is transient experimentation that has negligible risks in and itself, if not persistent. More stringent measures such as daily use are more relevant to individual and public health. Future research should examine possible improvements to definitions which include intensity of use (e.g., number of puffs per day) and persistence/duration of use, either via self-report or technology-assisted data capture.

The prospective relationship between a-priori intentions for and patterns of e-cigarette use among adults who smoke cigarettes.

BACKGROUND: Electronic (e-)cigarettes may help adult cigarette smokers achieve cigarette cessation, depending on patterns of e-cigarette use. Among cigarette smokers who do not use e-cigarettes, it is unclear if and how a-priori intentions for use are related to uptake patterns. Longitudinal studies have focused on established e-cigarette users or adolescent and young adult populations exclusively. METHODS: Within a nationwide randomized clinical trial (N = 638), adult cigarette smokers not currently using e-cigarettes were randomized (2:1) to receive (or not) one-month sampling of e-cigarettes. An exploratory factor analysis (EFA) was performed on an established 15-item measure assessing a-priori intentions for e-cigarette use to identify latent variables. Among those receiving e-cigarette products, regression models examined relationships between intentions and: 1) uptake (yes/no), 2) frequency (number of days per week), and 3) amount (puffing episodes per day) of e-cigarette use at one-month follow-up. RESULTS: Two factors emerged from the EFA: 1) cigarette-related intentions (e.g., cigarette cessation, no smell) and 2) novel appeal of e-cigarettes (e.g., flavors). Three items remained and were treated as separate intentions: "feels like cigarette smoking", "curiosity", and "affordability". In the final multivariable models, "feel like cigarette smoking" predicted more frequent e-cigarette use (ß = 0.187, SE = 0.086, p = 0.03); however, none of the five factors/intentions were significantly associated with uptake or amount of use. CONCLUSIONS: For adult cigarette smokers not currently using e-cigarettes, a-priori intentions for using e-cigarettes might not be predictive of if or how these products will be used in the future, suggesting that motives may not drive use behavior.