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Introduction: The current study sought to examine trends in indicators of dependence for youth vaping and smoking during a period of rapid evolution in the e-cigarette market., Aims and Methods: Data are from repeat cross-sectional online surveys conducted between 2017 and 2022 among youth aged 16-19 in Canada, England, and the United States (US). Participants were 23 145 respondents who vaped and/or smoked in the past 30 days. Four dependence indicators were assessed for smoking and vaping (perceived addiction, frequent strong urges, time to first use after waking, days used in past month) and two for vaping only (use events per day, e-cigarette dependence scale). Regression models examined differences by survey wave and country, adjusting for sex, age, race, and exclusive/dual use., Results: All six indicators of dependence increased between 2017 and 2022 among youth who vaped in the past 30 days (p < .001 for all). For example, more youth reported strong urges to vape at least most days in 2022 than in 2017 (Canada: 26.5% to 53.4%; England: 25.5% to 45.4%; US: 31.6% to 50.3%). In 2017, indicators of vaping dependence were substantially lower than for smoking; however, by 2022, youth vaping was associated with a greater number of days used in the past month (Canada, US), shorter time to first use (all countries), and a higher likelihood of frequent strong urges (Canada, US) compared to youth smoking., Conclusions: From 2017 to 2022, indicators of vaping dependence increased substantially. By 2022, vaping dependence indices were comparable to those of smoking., Implications: Indicators of vaping dependence among youth have increased substantially since 2017 to levels that are comparable to cigarette dependence among youth who smoke. Future research should examine factors underlying the increase in dependence among youth who vape, including changes to the nicotine profile and design of e-cigarette products., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.)

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.

Waterpipe tobacco (WPT) smoking is a public health concern, particularly among youth and young adults. The global spread of WPT use has surged since the introduction of pre-packaged flavored and sweetened WPT, which is widely marketed as a safer tobacco alternative. Besides flavorants and sugars, WPT additives include humectants, which enhance the moisture and sweetness of WPT, act as solvents for flavors, and impart smoothness to the smoke, thus increasing appeal to users. In the United States (U.S.), unlike cigarette tobacco flavoring (with the exception of menthol), there is no FDA product standard or policy in place prohibiting sales of flavored WPT. Research has shown that the numerous fruit, candy, and alcohol flavors added to WPT entice individuals to experience those flavors, putting them at an increased risk of exposure to WPT smoke-related toxicants. Additionally, burning charcoal briquettes-used as a heating source for WPT-contributes to the harmful health effects of WPT smoking. This review presents existing evidence on the potential toxicity resulting from humectants, sugars, and flavorants in WPT, and from the charcoal used to heat WPT. The review discusses relevant studies of inhalation toxicity in animal models and of biomarkers of exposure in humans. Current evidence suggests that more data are needed on toxicant emissions in WPT smoke to inform effective tobacco regulation to mitigate the adverse impact of WPT use on human health., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Toxicology.)

Introduction: Oral nicotine pouches (ONPs) are a new class of nicotine products. This scoping review summarizes evidence on ONPs and explores their potential public health impact., Aims and Methods: We conducted a structured literature search for empirical studies across three electronic databases through January 10, 2024. Outcomes included ONP product characteristics, use patterns, beliefs and perceptions, toxicity, and marketing and sales., Results: Sixty-two studies were included, 17 were industry-funded. Most studies were from the United States. While large variations across studies were observed in ONP youth prevalence estimates, nationally representative U.S. studies find current use at 1.5% and lifetime use below 2.5% through 2023. Between 35% and 42% of U.S. adolescents and young adults have heard of ONPs, and 9-21% of tobacco-naïve youth were susceptible to trying them. U.S. adult-use estimates varied widely (0.8%-3% current; 3%-16% lifetime use) and were limited to populations with a history of tobacco use. The chemical composition of ONPs suggests fewer harmful/potentially harmful compounds at lower levels than cigarettes and smokeless tobacco (SLT), except formaldehyde. Industry-funded studies find substantially less cytotoxicity compared to cigarettes and suggest that higher nicotine-strength ONPs can deliver nicotine at levels comparable to or higher than SLT or cigarettes, although with slower nicotine release than cigarettes. Evidence on the cytotoxicity of ONPs relative to SLT is mixed., Conclusions: ONPs appear to be less toxic than cigarettes and deliver comparable nicotine, presenting an alternative for combustible product users, although key data are mainly available from industry-funded studies. Data from independent research is critically needed. Industry marketing of ONPs may encourage initiation in youth and situational and dual use in adults., Implications: The review provides an initial assessment of the potential role of ONPs in harm reduction and aims to determine unintended consequences of their use (youth uptake and dual-use) and identify populations that disproportionately use the product. This information is essential for tobacco regulatory bodies in determining the net public health impact of nicotine pouches., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.)

Introduction: Some firms and marketers of electronic cigarettes (e-cigarettes; a type of electronic nicotine delivery system (ENDS)) and refill liquids (e-liquids) have made claims about the safety of ingredients used in their products based on the term "GRAS or Generally Recognized As Safe" (GRAS). However, GRAS is a provision within the definition of a food additive under section 201(s) (21 U.S.C. 321(s)) of the U.S. Federal Food Drug and Cosmetic Act (FD&C Act). Food additives and GRAS substances are by the FD&C Act definition intended for use in food, thus safety is based on oral consumption; the term GRAS cannot serve as an indicator of the toxicity of e-cigarette ingredients when aerosolized and inhaled (i.e., vaped). There is no legal or scientific support for labeling e-cigarette product ingredients as "GRAS". This review discusses our concerns with the GRAS provision being applied to e-cigarette products and provides examples of chemical compounds that have been used as food ingredients but have been shown to lead to adverse health effects when inhaled. The review provides scientific insight into the toxicological evaluation of e-liquid ingredients and their aerosols to help determine the potential respiratory risks associated with their use in e-cigarettes., Implications: The rise in prevalence of e-cigarette use and emerging evidence of adverse effects, particularly on lung health, warrant assessing all aspects of e-cigarette toxicity. One development is manufacturers' stated or implied claims of the safety of using e-cigarette products containing ingredients determined to be "Generally Recognized As Safe" (GRAS) for use in food. Such claims, typically placed on e-cigarette product labels and used in marketing, are unfounded, as pointed out by the United States Food and Drug Administration (FDA)1 and the Flavor and Extract Manufacturers Association (FEMA)2. Assessment of inhalation health risks of all ingredients used in e-liquids, including those claimed to be GRAS, is warranted., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.)

E-liquids contain combinations of chemicals, with many enhancing the sensory attractiveness of the product. Studies are needed to understand and characterize e-liquid ingredients, particularly flavorings, to inform future research and regulations of these products. We identified common flavor ingredients in a convenience sample of commercial e-liquids using gas chromatography-mass spectrometry. E-liquid flavors were categorized by flavor descriptors provided on the product packaging. A Flavor Ingredient Wheel was developed to link e-liquid flavor ingredients with flavor categories. An analysis of 109 samples identified 48 flavor ingredients. Consistency between the labeled flavor and ingredients used to produce such flavor was found. Our novel Flavor Ingredient Wheel organizes e-liquids by flavor and ingredients, enabling efficient analysis of the link between ingredients and their flavor profiles and allowing for quick assessment of an e-liquid ingredient's flavor profile. Investigating ingredient profiles and identifying and classifying commonly used chemicals in e-liquids may assist with future studies and improve the ability to regulate these products.

Background: The global market share for cigarettes with flavor capsules has grown exponentially over the last decade, particularly in Latin America. When smoking, consumers crush a liquid capsule in the filter that flavors the smoke. Little is known about the chemical constituents of the liquids in capsules or their potential health risks., Methods: Based on consumer data and availability in Mexico and Guatemala, 31 flavor capsule brands were purchased (19 and 12, respectively) in 2020. Since some cigarettes included multiple capsules in a stick (up to 2) or pack (up to 4), the final analytic sample included 50 capsules. We conducted qualitative and quantitative analyses using gas chromatography with mass spectrometry (GC-MS, Agilent Technologies, Inc)., Results: The qualitative analysis detected 296 compounds (range = 9-67 per capsule), and all capsules contained menthol. Among the compounds detected in more than half the sample were limonene, menthone, benzaldehyde, eucalyptol, and triacetin. Traces of nicotine were found in 22% of the capsules. In the quantitative analysis, menthol concentrations were 33 times greater than the next most common compound (limonene). Benzyl alcohol and vanillin were also found in high concentrations. Comparing same-brand varieties across countries showed substantial variability in the concentration of menthol and other compounds., Conclusions: Menthol is an omnipresent constituent in capsule cigarettes, perhaps because of its anesthetizing and reinforcing addictive properties. Other compounds found are toxic, potentially carcinogenic, and may enhance addictiveness. Variance in the presence and concentrations of such compounds highlights the importance of product standards to regulate capsule content., Implications: This study evaluated the chemical content of capsule cigarettes from two Latin American countries that have two of the highest market shares for capsule cigarettes worldwide. Compared to other studies, our assessment included brand varieties from two countries to compare the differences in chemical content by country. Our results yield that menthol is found in all capsules, and that other chemicals found may prolong nicotine exposure and therefore reinforce the addictive properties of cigarettes., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: There is limited long-term and independent research on heated tobacco products (HTPs). We compared people who used HTPs with those who used nicotine vaping products (NVP) or cigarettes on smoker identity, indicators of effectiveness and, among NVP/HTP users, perceptions of these products., Methods: Adults exclusive cigarette smokers (N = 45) and ex-smokers with medium/long-term (>3months) NVP (N = 46) or HTP use (N = 45) were recruited in London, UK. Participants completed a questionnaire assessing socio-demographics, smoking characteristics, smoker identity, dependence, intention to stop and attitudes towards HTP/NVP., Results: In adjusted analysis, people who used cigarettes (Mean Difference (MD) = 1.4, 95%Confidence Intervals (CI) 0.7,2.0) and HTPs (MD = 0.8, 95%CI 0.1, 1.5) reported stronger smoker identities than those who used NVPs. Compared with smokers, HTP/NVP users had lower cravings for cigarettes (MD = 3.0, 95%CI 1.6, 4.3; MD = 3.1, 95%CI 1.9, 4.3, respectively), and higher intention to stop product use (MD = -0.8, 95%CI -1.7,-0.01; MD = -1.2, 95%CI -2.0, -0.3, respectively). People using HTPs or NVPs reported similar perceived product satisfaction (HTP:M = 3.4, 95%CI 2.8, 3.9; NVP:M = 3.0, 95%CI 2.5, 3.5), efficacy for smoking cessation (HTP:M = 4.5, 95%CI 4.2, 4.9; NVP:M = 4.6, 95%CI 4.3, 4.9) and safety (HTP:M = 2.1, 95%CI 2.0, 2.2; NVP:M = 2.0, 95%CI 1.8, 2.1). HTP users reported greater perceived addictiveness than NVPs (MD = 0.3, 95%CI 0.2, 0.6)., Conclusions: HTP and NVP users perceived products to be similarly acceptable and effective suggesting that HTPs, like NVPs, may support smoking cessation. However, since HTP use appears to maintain a stronger smoker identity and perceived addiction, this may suggest a more limited role of HTP for a permanent transition away from cigarettes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: Cannabis use may introduce risks and/or benefits among people living with cancer, depending on product type, composition, and nature of its use. Patient knowledge of tetrahydrocannabinol (THC) or cannabidiol (CBD) concentration could provide information for providers about cannabis use during and after treatment that may aide in risk and benefit assessments. This study aimed to examine knowledge of THC or CBD concentration among patients living with cancer who consume cannabis, and factors associated with knowledge of cannabinoid concentrations., Methods: People living with cancer who consumed cannabis since their diagnosis (n = 343) completed an anonymous, mixed-mode survey. Questions assessed usual mode of delivery (MOD), knowledge of THC/CBD concentration, and how source of acquisition, current cannabis use, and source of instruction are associated with knowledge of THC/CBD concentration. Chi-square and separate binary logistic regression analyses were examined and weighted to reflect the Roswell Park patient population., Results: Less than 20% of people living with cancer had knowledge of THC and CBD concentration for the cannabis products they consumed across all MOD (smoking- combustible products, vaping- vaporized products (e-cigarettes), edibles-eating or drinking it, and oral- taking by mouth (pills)). Source of acquisition (smoking-AOR:4.6, p < 0.01, vaping-AOR:5.8, p < 0.00, edibles-AOR:2.6, p < 0.04), current cannabis use (edibles-AOR:5.4, p < 0.01, vaping-AOR: 11.2, p < 0.00, and oral-AOR:9.3, p < 0.00), and source of instruction (vaping only AOR:4.2, p < 0.05) were found to be variables associated with higher knowledge of THC concentration., Conclusion: Self-reported knowledge of THC and CBD concentration statistically differed according to MOD, source of acquisition, source of instruction, and current cannabis use., (© 2024. The Author(s).)

Heated Tobacco Products (HTPs) purport to reduce exposure to tobacco-related toxicants compared to combustible cigarettes. This cross-sectional study examined the content of nicotine, two humectants (propylene glycol (PG) and vegetable glycerin (VG)), and four tobacco-specific nitrosamines (TSNAs: NNN, NNK, NAT, and NAB) in the tobacco filler of a popular HTP brand (IQOS). Non-menthol and menthol IQOS sticks were purchased from nine countries between 2017 and 2020 and were classified into two versions ("Bold" and "Light") using Philip Morris's flavor descriptors. The average nicotine concentration was 4.7 ± 0.5 mg/stick, and the highest nicotine concentration was found in products from Japan (5.1 ± 0.2 mg/stick). VG was the dominant humectant found in all sticks, with an average concentration of (31.5 ± 2.3 mg/stick). NNN, NNK, and NAT were substantially higher in the "Bold" sticks than the "Light" sticks. Significant differences between countries for TSNAs were also observed: the NAT and NAB contents were the highest in the "Light" products from Canada (192.5 ± 24.1 and 22.9 ± 1.0 ng/stick, respectively); the NNK concentration was the highest in the "Bold" products from Poland (64.8 ± 7.9 ng/stick); and the highest NNN concentrations were observed in the "Bold" products from South Africa (488.9 ± 26.7 ng/stick). As NNN and NNK are known human carcinogens, and as humectants like PG and VG can degrade into toxic carbonyl compounds upon heating, monitoring the concentration of these chemicals in HTPs is important for protecting users' health and ensuring compliance with regulations.

Background: Availability of flavours and potential modified risk tobacco product (MRTP) claims may influence young adults' (YAs') perceptions of and intentions to use nicotine pouches ('pouches')., Methods: YAs aged 21-34 years (N=47, M age =24.5, SD =3.1) with past-month nicotine/tobacco use (10.6% cigarette-only, 51.1% e-cigarette-only, 38.3% dual use) and no intention to quit were randomised to self-administer four Zyn 3 mg nicotine pouches in a 4 (flavour; within-subjects: smooth, mint, menthol, citrus) × 2 (MRTP claim on packaging; between subjects: present or absent) mixed-factorial design. After self-administering each pouch, participants reported appeal, use intentions and perceived harm compared with cigarettes and e-cigarettes. Three mixed-factorial analysis of variances (ANOVAs) examined main and interactive effects of flavour and MRTP claim on appeal, use intentions and comparative harm perceptions., Results: Mint ( M =55.9, SD =26.4), menthol ( M =49.7, SD =26.8) and citrus ( M =46.6, SD =24.8) flavours were significantly more appealing than smooth ( M =37.6, SD =25.4; p<0.001). MRTP claim did not significantly affect product appeal (p=0.376). Use intentions were greater for mint ( M =2.6, SD =1.3) and menthol ( M =2.0, SD =1.1) flavours than smooth ( M =1.8, SD =1.0; p=0.002). Flavour did not affect comparative harm perceptions (p values>0.418). MRTP claims increased use intention (p=0.032) and perceptions of pouches as less harmful than cigarettes (p=0.011), but did not affect perceived harm relative to e-cigarettes (p=0.142). Flavour × MRTP claim interactions were not significant., Conclusions: Flavoured (vs smooth) pouches were more appealing to YAs. MRTP claims reduced perceived harm of pouches compared with cigarettes; however, intentions to switch were low. To protect YAs' health, regulatory restrictions could target flavours and MRTP claims., Competing Interests: Competing interests: No, there are no competing interests., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Nicotine vaping products (NVPs) and heated tobacco products (HTPs) are designed to replicate the sensory and behavioural aspects of smoking cigarettes while avoiding combustion. The success of these products as harm reduction tools will partially depend on their ability to satisfy smokers and alleviate nicotine-related withdrawal symptoms. This study aims to compare short-term effects of NVPs (Juul and Aspire PockeX) versus HTPs (IQOS) on smoking-related withdrawal relief, product satisfaction, intention to switch to NVP/HTP, perceptions and attitudes in UK adult cigarette smokers naïve to these products. In a randomized cross-over study, 45 participants visited the lab twice, at each visit trying one of the two products (NVP/HTP) and completing a questionnaire. Responses were normalized on a 0-100% scale and mean differences (MD) between NVP and HTP scores computed, with positive and negative MD values indicating greater endorsement for NVP and HTP, respectively. Cigarette cravings were reduced similarly (~ 20.0%) by both products (MD = 4.5%, 95%Confidence Interval (CI) - 4.8, 13.8). Direct positive effects (MD = - 3.5%, 95%CI - 7.2, 0.2) and adverse side effects (MD = 1.8%, 95%CI - 0.3, 3.8) were comparable after each product use, though marginally favouring HTPs. HTPs were perceived as more satisfying overall (MD = - 13.2%, 95%CI - 20.3 - 6.1) than NVPs but both were perceived as similarly addictive (MD = 3.6%, 95%CI - 4.6, 11.8), relative to cigarettes. Intention to switch to either product was comparable (MD = 4.0%, 95%CI - 5.7, 13.8). Comparison of acute use of NVP versus HTP in a sample of UK smokers naïve to these products suggests that HTPs are perceived as more satisfying than NVPs, though still less satisfying than cigarettes.Registration: The analysis plan was pre-registered, and it is available at https://osf.io/6ymdu., (© 2023. The Author(s).)

Importance: Pregnant adolescents sometimes use cigarettes; however, little is known about e-cigarette use among pregnant adolescents, a population with increased health vulnerability., Objective: To examine yearly trends, sociodemographic and pregnancy-related determinants, and the association with small-for-gestational-age (SGA) birth of e-cigarette and/or cigarette use during late pregnancy among adolescents., Design, Setting, and Participants: This cohort study used existing data from the 2016-2021 Pregnancy Risk Assessment Monitoring System on 10 428 US adolescents aged 10 to 19 years who had a singleton birth with complete data on e-cigarette or cigarette use and SGA birth., Exposure: Adolescents reported e-cigarette and cigarette use during the last 3 months of pregnancy., Main Outcomes and Measures: SGA birth (birth weight below the 10th percentile for the same sex and gestational duration) was determined from birth certificates. Multivariable logistic regression was used to compare the odds of SGA birth across pregnant adolescents who exclusively used e-cigarettes, exclusively used cigarettes, used e-cigarettes and cigarettes, or did not use either., Results: Of the 10 428 pregnant adolescents, 72.7% were aged 18 or 19 years; 58.9% self-identified as White and 23.3% as Black; and 69.8% were non-Hispanic. The weighted prevalence of exclusive e-cigarette use during late pregnancy increased from 0.8% in 2016 to 4.1% in 2021, while the prevalence of exclusive cigarette use decreased from 9.2% in 2017 to 3.2% in 2021. The prevalence of dual use fluctuated, ranging from 0.6% to 1.6%. White pregnant adolescents were more likely than those who self-identified as another race and ethnicity to use e-cigarettes (2.7% vs 1.0% for American Indian or Alaska Native adolescents, 0.8% for Asian or other race adolescents, 0.6% for Black adolescents, and 0.7% for multiracial adolescents). Compared with those who did not use either product, adolescents who exclusively used e-cigarettes (16.8% vs 12.9%; confounder-adjusted odds ratio [AOR], 1.68 [95% CI, 0.89-3.18]) or who used cigarettes and e-cigarettes (17.6% vs 12.9%; AOR, 1.68 [95% CI, 0.79-3.53]) had no statistically significant difference in risk of SGA birth. However, adolescents who exclusively used cigarettes had a more than 2-fold higher risk of SGA birth (24.6% vs 12.9%; AOR, 2.51 [95% CI, 1.79-3.52])., Conclusions and Relevance: This cohort study suggests that pregnant adolescents increasingly used e-cigarettes, with the highest use among White adolescents. Results from this analysis found that, unlike cigarette use, e-cigarette use during late pregnancy was not statistically significantly associated with an increased risk of SGA birth among adolescents. Due to the uncertainty of this nonsignificant association, future research could benefit from a larger sample size.

Background: This clinical experiment tested the effects of exposure to e-cigarettes with WS-23 or menthol cooling additives on user appeal and sensory attributes, and, secondarily, whether WS-23 effects generalised across base characterising flavour, nicotine concentration, or nicotine/tobacco product use status., Methods: In this within-participant double-blind experiment, adult tobacco/nicotine users administered standardised puffs of 18 different e-cigarette solutions in randomised sequences using a pod-style device. Each of three base characterising e-cigarette flavour solutions ('bold tobacco', 'mango,' 'wintergreen') in both 2% and 4% concentrations of nicotine benzoate salt were manipulated by adding either: (1) Menthol (0.5%), (2) WS-23 (0.75%) or (3) No cooling agent. After each administration, participants rated 3 appeal and 5 sensory attributes (0-100 scales)., Results: Participants (n=84; M(SD)=38.6 (13.6) years old) were either exclusive e-cigarette (25.0%), cigarette (36.9%) or dual (38.1%) users. WS-23 versus no coolant products produced higher liking, willingness to use again, smoothness, and coolness and lower disliking, bitterness, and harshness ratings (|B| difference range: 4.8 to 20.1; ps<0.005). Menthol (vs no coolant) increased willingness to use again and reduced harshness and coolness (ps<0.05). Flavours with WS-23 (vs menthol) were rated as smoother, cooler and less harsh (ps<0.05). Coolant effects did not differ by base flavour, nicotine concentration, or tobacco use status., Conclusions: Adding synthetic coolant WS-23 to e-cigarettes appears to make the vaping user experience more appealing, regardless of characterising base flavour. Regulatory agencies should be aware that the manufacturing process of adding synthetic coolants may increase the attractiveness of various e-cigarette products.Cite Now., Competing Interests: Competing interests: MLG has served as a member of the Scientific Advisory Board to Johnson & Johnson; he has also consulted with both the WHO and Campaign for TobaccoFree Kids on toxicity of tobacco products and tobacco control products; MLG is also a Member of the IASLC Tobacco Control and Smoking Cessation Committee; and a leadership role with the American Association for Cancer Research., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Rationale: Due to the relatively short existence of alternative tobacco products, gaps exist in our current understanding of their long-term respiratory health effects. We therefore undertook the first-ever side-by-side comparison of the impact of chronic inhalation of aerosols emitted from electronic cigarettes (EC) and heated tobacco products (HTP), and combustible cigarettes (CC) smoke., Objectives: To evaluate the potential differential effects of alternative tobacco products on lung inflammatory responses and efficacy of vaccination in comparison to CC., Methods: Mice were exposed to emissions from EC, HTP, CC, or air for 8 weeks. BAL and lung tissue were analyzed for markers of inflammation, lung damage, and oxidative stress. Another group was exposed for 12 weeks and vaccinated and challenged with a bacterial respiratory infection. Antibody titers in BAL and sera and pulmonary bacterial clearance were assessed., Main Results: EC- and HTP-aerosols significantly augmented lung immune cell infiltrates equivalent to that achieved following CC-exposure. HTP and CC significantly increased neutrophil numbers compared to EC. All products augmented numbers of B cells, T cells, and pro-inflammatory IL17A + T cells in the lungs. Decreased lung antioxidant activity and lung epithelial and endothelial damage was induced by all products. EC and HTP differentially augmented inflammatory cytokines/chemokines in the BAL. Generation of immunity following vaccination was impaired by EC and HTP but to a lesser extent than CC, with a CC > HTP > EC hierarchy of suppression of pulmonary bacterial clearance., Conclusions: HTP and EC-aerosols induced a proinflammatory pulmonary microenvironment, lung damage, and suppressed efficacy of vaccination., (© 2023. The Author(s).)

Importance: Smoking cigarettes during pregnancy can impair maternal and child health, and pregnant individuals have increasingly used electronic cigarettes (e-cigarettes) for various reasons, including quitting smoking., Objective: To assess smoking abstinence rates among pregnant individuals who used e-cigarettes compared with those who used nicotine replacement therapy (NRT)., Design, Setting, and Participants: This cohort study is a secondary data analysis of phase 8 of the US Pregnancy Risk Assessment Monitoring System, conducted between 2016 and 2020. Eligible participants included pregnant individuals who smoked combustible cigarettes within the 3 months before pregnancy and either used e-cigarettes or NRT during pregnancy. Data analysis was conducted from March 2022 to April 2023., Exposures: Combustible cigarette use within 3 months before pregnancy and use of either e-cigarettes or NRT during pregnancy., Main Outcomes and Measures: The primary outcome was the individual's self-reported smoking abstinence status during the last 3 months of pregnancy. Weighted percentages were reported and weighted multivariable logistic regression models were used to examine the association of e-cigarette use vs NRT with smoking abstinence. A propensity score was used to control for confounding by sociodemographics, pregnancy characteristics, prepregnancy smoking intensity, depression, behavioral support, and hookah use., Results: The cohort included 1329 pregnant individuals (759 ≥25 years [60.2%]; 766 non-Hispanic White individuals [79.8%]) of whom 781 had an education level of high school or lower (61.4%), and 952 had an annual household income of $48 000 or less (81.5%). Of the 1329 individuals, 890 (unweighted percentage, 67.0%) were existing e-cigarette users, 67 (unweighted percentage, 5.0%) were new e-cigarette users, and 372 (unweighted percentage, 28.0%) were NRT users. Compared with individuals who used NRT during pregnancy, individuals who used e-cigarettes had a higher rate of smoking abstinence in late pregnancy (456 individuals [50.8%] vs 67 individuals [19.4%]; propensity score adjusted odds ratio [OR], 2.47; 95% CI, 1.17-5.20; P = .02). In the secondary analysis stratified by the timing of e-cigarette use initiation, existing users of e-cigarettes who initiated before pregnancy had a higher smoking abstinence rate than NRT users (446 users [53.1%] vs 67 users [19.4%]; adjusted OR, 2.61; 95% CI, 1.23-5.51; P = .01). However, new e-cigarette users who initiated use during pregnancy had a similar smoking abstinence rate in late pregnancy when compared with NRT users (10 users [20.6%] vs 67 users [19.4%]; adjusted OR, 1.13; 95% CI, 0.22-5.87; P = .88)., Conclusions and Relevance: These findings suggest that individuals who used e-cigarettes during pregnancy had a higher smoking abstinence rate in late pregnancy than individuals who used NRT, especially for those who initiated e-cigarette use before pregnancy, indicating that replacement of cigarettes with e-cigarettes during pregnancy may be a viable strategy for harm reduction.

Background: Sex and racial/ethnic identity-specific cut-points for validating tobacco use using Wave 1 (W1) of the Population Assessment of Tobacco and Health (PATH) Study were published in 2020. The current study establishes predictive validity of the W1 (2014) urinary cotinine and total nicotine equivalents-2 (TNE-2) cut-points on estimating Wave 4 (W4; 2017) tobacco use., Methods: For exclusive and polytobacco cigarette use, weighted prevalence estimates based on W4 self-report alone and with exceeding the W1 cut-point were calculated to identify the percentage missed without biochemical verification. Sensitivity and specificity of W1 cut-points on W4 self-reported tobacco use status were examined. ROC curves were used to determine the optimal W4 cut-points to distinguish past 30-day users from non-users, and evaluate whether the cut-points significantly differed from W1., Results: Agreement between W4 self-reported use and exceeding the W1 cut-points was high overall and when stratified by demographic subgroups (0.7%-4.4% of use was missed if relying on self-report alone). The predictive validity of using the W1 cut-points to classify exclusive cigarette and polytobacco cigarette use at W4 was high (>90% sensitivity and specificity, except among polytobacco Hispanic smokers). Cut-points derived using W4 data did not significantly differ from the W1-derived cut-points [e.g., W1 exclusive = 40.5 ng/mL cotinine (95% confidence interval, CI: 26.1-62.8), W4 exclusive = 29.9 ng/mL cotinine (95% CI: 13.5-66.4)], among most demographic subgroups., Conclusions: The W1 cut-points remain valid for biochemical verification of self-reported tobacco use in W4., Impact: Findings from can be used in clinical and epidemiologic studies to reduce misclassification of cigarette smoking status., (©2023 American Association for Cancer Research.)

Rationale: Vaping has become a popular method of inhaling various psychoactive substances. While evaluating respiratory effects of vaping have primarily focused on nicotine-containing products, cannabidiol (CBD)-vaping is increasingly becoming popular. It currently remains unknown whether the health effects of vaping nicotine and cannabinoids are similar., Objectives: This study compares side by side the pulmonary effects of acute inhalation of vaporised CBD versus nicotine., Methods: In vivo inhalation study in mice and in vitro cytotoxicity experiments with human cells were performed to assess the pulmonary damage-inducing effects of CBD or nicotine aerosols emitted from vaping devices., Measurements and Main Results: Pulmonary inflammation in mice was scored by histology, flow cytometry, and quantifying levels of proinflammatory cytokines and chemokines. Lung damage was assessed by histology, measurement of myeloperoxidase activity and neutrophil elastase levels in the bronchoalveolar lavage fluid and lung tissue. Lung epithelial/endothelial integrity was assessed by quantifying BAL protein levels, albumin leak and pulmonary FITC-dextran leak. Oxidative stress was determined by measuring the antioxidant potential in the BAL and lungs. The cytotoxic effects of CBD and nicotine aerosols on human neutrophils and human small airway epithelial cells were evaluated using in vitro air-liquid interface system. Inhalation of CBD aerosol resulted in greater inflammatory changes, more severe lung damage and higher oxidative stress compared with nicotine. CBD aerosol also showed higher toxicity to human cells compared with nicotine., Conclusions: Vaping of CBD induces a potent inflammatory response and leads to more pathological changes associated with lung injury than vaping of nicotine., Competing Interests: Competing interests: MLG reports research grant from Pfizer and personal fees from Johnson & Johnson, outside of this work., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: As summarised in the most recent Cochrane review, the few clinical trials on e-cigarettes are largely focused on smoking cessation. We aimed to determine the naturalistic uptake, use, and impact of e-cigarettes among adults who may or may not want to stop smoking., Methods: In this naturalistic, randomised, controlled clinical trial, adult smokers, across the motivational spectrum and with minimal history of e-cigarette use, were recruited online from the general community within 11 cities across the USA. Participants were randomly assigned (2:1) to either receive either a free 4-week supply of flavoured, tank-style e-cigarette, or not. E-cigarette group participants received a battery and device with up to 30 pre-filled tanks, offered among five flavours, with minimal instructions on use. The study's primary purpose was to descriptively assess naturalistic uptake and usage of the e-cigarette, and to secondarily assess its impact on smoking behavior. The latter, assessed through six months of follow-up, included: a) self-reported 7-day point prevalence abstinence, b) incidence of quit attempts, and c) smoking reduction. This trial is registered at ClinicalTrials.gov, NCT03453385., Findings: Between 5/2018 and 3/2022, 638 adult smokers were enrolled and randomly assigned (427 in the e-cigarette group and 211 in the no-product control group). Uptake of e-cigarettes was robust: approximately 70% of participants used the product, with average usage exceeding 4 days per week during the initial 30 days. Based on an intent-to-treat approach where missing data is imputed as smoking, almost all behavioral outcomes favored the e-cigarette group relative to no-product control, including point prevalence abstinence at six months (Odds Ratio [OR] = 1.8; 95% Confidence Interval [CI] = 1.0-3.1), cumulative incidence of 24-hr quit attempts (OR = 1.5; 95% CI = 1.0-2.2), and having reduced smoking by at least 50% since baseline (OR = 1.8; 95% CI = 1.2-2.7). Results were similar under an alternative imputation., Interpretation: Complementing cessation-focused trials, results suggest that unguided e-cigarette use also leads to smoking cessation, allaying the notion that causal effects of e-cigarettes on cessation are not reflective of real-world scenario of self-determined use. For smokers who may not be able to quit using existing pharmacologic approaches, e-cigarettes may be considered to achive that purpose., Funding: National Cancer Institute., Competing Interests: KMC has served as a paid expert witness in litigation filed against the tobacco industry. KMG has provided consultation to Jazz Pharmaceuticals and has received research funding from Aelis Farma. MLG has served as a member of the Scientific Advisory Board to Johnson & Johnson; he has also consulted with both the World Health Organization and Campaign for Tobacco Free Kids on toxicity of tobacco products and tobacco control products; MLG is also a Member of the IASLC Tobacco Control and Smoking Cessation Committee; and a leadership role with the American Association for Cancer Research. JD is a co-owner of Behavioral Activation Tech LLC, a small business that develops digital interventions for behavioral health treatment. E-cigarette products (tanks and liquids) were purchased directly from NJoy; no study support provided from industry. All other authors declare no competing interests., (© 2023 The Author(s).)

Introduction: In December 2022, California (CA) enforced a voter-approved regulation restricting the retail sale of flavoured tobacco products, including menthol cigarettes. Shortly after, new products emerged on the market containing similar blue and green package colours yet with 'non-menthol' descriptors. Using chemical analyses, we measured the content of menthol and 15 other cooling chemicals in Californian cigarettes with 'non-menthol' descriptors and compared concentrations to similar 'menthol'-labelled counterparts available in New York State (NY)., Methods: A convenience sample of 10 brands and types of cigarettes in CA were purchased based on package colours suggesting a cooling effect and/or 'non-menthol' descriptors. The exact brand and type of cigarettes (with menthol descriptors) were purchased in NY. Cigarettes from CA were compared with equivalent cigarettes from NY on package design and colours, cigarette physical characteristics and the presence of cooling additives., Results: Menthol was not detected in any CA cigarette, except for Maverick-green box type, while its presence was confirmed in most NY counterpart products. A synthetic cooling chemical WS-3 was not detected in any NY cigarettes but was detected in four CA brands and types with implied cooling effect, ranging from 1.24±0.04 to 1.97±0.05 mg/cigarette., Conclusion: While manufacturers have removed menthol descriptors from CA packaging and the menthol ingredient from cigarettes, synthetic cooling chemicals detected in several CA brands suggest that cooling sensory effects may still be sustained. Policymakers must consider both the chemical ingredients themselves and sensory effects in future regulatory approaches., Competing Interests: Competing interests: MLG received a research grant from and served as an advisory board member to pharmaceutical companies that manufacture smoking cessation drugs., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: MLG received a research grant from Pfizer and served as a member of a scientific advisory board to Johnson & Johnson. All other authors have no competing interests to declare.

Introduction: Electronic nicotine delivery systems (ENDS) are known to contain heavy metals such as lead (Pb), nickel (Ni) and chromium (Cr). The presence of heavy metals in ENDS may be due to contamination of e-liquids or leaching from elements of the ENDS device. This study investigates differences in ENDS metal concentrations between product type, year of purchase, country of purchase and e-liquid flavour., Methods: Various open-system (refill e-liquids; n=116) and closed-system (prefilled with e-liquid; n=120) products were purchased in 2017 and 2018 from the USA, England, Canada and Australia. Electrothermal atomic absorption spectroscopy was used to analyse each product for Pb, Ni and Cr. Multiple linear regression and Kruskal-Wallis non-parametric statistical tests were conducted using GraphPad., Results: Linear regression showed system type, year of purchase (not supported by Kruskal-Wallis), country of purchase and flavour type each had significant impacts on heavy metal concentrations. Open-system e-liquid samples showed no quantifiable levels of heavy metals. Closed-system samples contained concerningly high concentrations of Pb, Ni and Cr. Closed-system samples from the USA commonly displayed higher average heavy metal concentrations than those from England. Some fruit and mint-flavoured closed-system products showed higher heavy metal concentrations than tobacco-flavoured products., Conclusion: The presence of heavy metals only in closed-system products suggests that metals may be leaching from ENDS device parts. Highly variable heavy metal concentrations between ENDS products demonstrate that various product characteristics may affect the degree of leaching and that there is a need for further regulation of these products., Competing Interests: Competing interests: MLG reports grants from and served as an advisory board member to pharmaceutical companies that manufacture smoking cessation drugs. Other authors declare no conflict of interest., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

This perspective summarizes available evidence on biomarkers of exposure in electronic nicotine delivery system (ENDS) users to aid the overall assessment of the health consequences of using ENDS. Identification of novel biomarkers of exposure specific to ENDS use remains challenging because chemicals emitted from ENDS devices have many familiar sources. The biomarker levels of many tobacco-related toxicants measured in biological samples collected from ENDS users did not differ significantly from non-users, except for nicotine metabolites and a small number of biomarkers of exposure to volatile organic compounds and tobacco-specific tobacco nitrosamines. Several studies have shown that while exposed to nicotine, long-term exclusive ENDS users showed significantly lower levels of toxicant biomarkers than cigarette smokers. Studies have also shown that concurrent users of ENDS and combustible cigarettes ('dual users') are not reducing overall exposure to harmful toxicants compared to exclusive cigarette smokers. Because of an absence of validated ENDS-specific biomarkers, we recommend combining several biomarkers to differentiate tobacco product user groups in population-based studies and monitor ENDS compliance in randomized controlled trials. Using a panel of biomarkers would provide a better understanding of health effects related to ENDS use.

South Korea is the world's second-largest heated tobacco product (HTP) market after Japan. HTP sales in South Korea have increased rapidly since May 2017, accounting for 10.6% of the total tobacco market in 2020. Despite this, little is known as to why HTP consumers who were current and former smokers started using HTPs and used them regularly. We analyzed cross-sectional data for 1815 adults (aged 19+) who participated in the 2020 International Tobacco Control (ITC) Korea Survey, of whom 1650 were HTP-cigarette consumers (those who reported smoking cigarettes and using HTPs ≥ weekly) and 165 were exclusive HTP consumers (using HTPs ≥ weekly) who were former or occasional smokers (smoking cigarette < weekly). Respondents were asked to report the reason(s) they used HTPs, with 25 possible reasons for HTP-cigarette consumers and 22 for exclusive HTP consumers. The most common reasons for initiating HTP use among all HTP consumers were out of curiosity (58.9%), family and friends use HTPs (45.5%), and they like the HTP technology (35.9%). The most common reasons for regularly using HTPs among all HTP consumers were that they were less smelly than cigarettes (71.3%), HTPs are less harmful to own health than cigarettes (48.6%), and stress reduction (47.4%). Overall, 35.4% of HTP-cigarette consumers reported using HTPs to quit smoking, 14.7% to reduce smoking but not to quit, and 49.7% for other reasons besides quitting or reducing smoking. In conclusion, several common reasons for initiating and regularly using HTPs were endorsed by all HTP consumers who were smoking, had quit smoking completely, or occasionally smoked. Notably, only about one-third of HTP-cigarette consumers said they were using HTPs to quit smoking, suggesting that most had no intention of using HTPs as an aid to quit smoking in South Korea.

Introduction: This study examines predictors of trajectories of cigarette and e-cigarette use among a cohort of US adolescents transitioning into young adulthood. Comparing trajectories of each tobacco product is important to determine if different intervention targets are needed to prevent progression to daily use., Methods: Latent trajectory class analyses identified cigarette and e-cigarette use (never, ever excluding past 12-month, past 12-month (excluding past 30-day (P30D)), P30D 1-5 days, P30D 6+ days) trajectory classes, separately, among US youth (12-17; N = 10,086) using the first 4 waves (2013-2017) of data from the nationally representative PATH Study. Weighted descriptive analyses described the class characteristics. Weighted multinomial logistic regression analyses examined demographic, psychosocial, and behavioral predictors of class membership., Results: Younger adolescents 12-15 years had lower tobacco use compared to 16-17 year olds and less stable classes. In the 16-17 year group, there were five unique trajectories of cigarette smoking, including a Persistent High Frequency class. Four e-cigarette use trajectories were identified; but not a persistent use class. Shared predictors of class membership for cigarettes and e-cigarettes included mental health problems, other tobacco use, marijuana use, and poorer academic achievement. Male sex and household tobacco use were unique e-cigarette trajectory class predictors., Conclusions: There was no evidence that initiation with e-cigarettes as the first product tried was associated with cigarette progression (nor cigarettes as first product and e-cigarette progression). Interventions should focus on well-established risk factors such as mental health and other substance use to prevent progression of use for both tobacco products., Implications: Using nationally representative data and definitions of use that take into account frequency and recency of use, longitudinal 4-year trajectories of e-cigarette and cigarette use among US adolescents transitioning into young adulthood were identified. Results among 16-17-year olds revealed a class of persistent high frequency cigarette smoking that was not identified for e-cigarette use. Cigarette use progression was not associated with e-cigarettes as the first product tried. Risk factors for progression of use of both products included mental health and other substance use, which are important prevention targets for both tobacco products., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.)

Introduction: POD electronic nicotine delivery systems (ENDS), often containing high concentrations of nicotine salts, have replaced MODs (ie, open/modifiable devices) as the most popular devices. The purpose of this study was to compare device/liquid characteristics, use behavior, and nicotine exposure between POD and MOD users., Methods: Data from the initial visit of a prospective observational study of exclusive ENDS users compared MOD (n = 48) and POD (n = 37) users. Participants completed questionnaires on demographic characteristics, patterns of ENDS use, and ENDS features. A urine sample was collected to test for cotinine and an ENDS liquid sample was collected to test for nicotine and salts. Puff topography was captured during an ad libitum bout at the end of the session., Results: MOD and POD users did not differ on demographic characteristics. MOD users reported purchasing more liquid in the past month than POD users (180.4 ± 28.0 vs. 50.9 ± 9.0 ml, p < .001). Differences in characteristics of devices used by MOD and POD users included flavor type (p = .029), nicotine concentration (liquids used by MOD users contained less nicotine than those used by POD users: 8.9 ± 2.0 vs. 41.6 ± 3.2 mg/ml, p < .001), and presence of the nicotine salt (fewer MOD liquids had salts present than POD liquids: 11.9% vs. 77.4%, p < .001). User groups did not differ on urinary cotinine levels or puff topography (ps > .05)., Conclusions: Despite different characteristics of MOD and POD ENDS, users of those products are exposed to similar amounts of nicotine, likely due to using more liquid among MOD users., Implications: This study directly compares ENDS product characteristics, user behavior, and nicotine exposure between MOD and POD ENDS users. Although POD products contained higher nicotine concentrations compared to MOD products, users of PODs reported consuming less liquid than MOD users. Ultimately, MOD and POD users were exposed to similar levels of nicotine, suggesting users behaviorally compensate for differences in product characteristics., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Most adults who regularly use e-cigarettes or Electronic Nicotine Delivery Systems (ENDS) desire to discontinue use. ENDS use can result symptoms of nicotine withdrawal and dependence which can make it more difficult to discontinue use. Brief, valid assessment of nicotine dependence among adults who use ENDS is needed to guide treatment for nicotine dependence in this group. We sought to develop a brief, valid instrument to measure nicotine dependence among adults seeking to discontinue ENDS in a busy Quitline., Methods: In this cross-sectional design, we examined content, construct, and concurrent validity of the Roswell ENDS Nicotine Dependence Scale (Roswell eND Scale) and the Penn State E-Cigarette Dependence Index (Penn State eCDI). Participants who called the New York Quitline from November 2019 to June 2020 seeking to discontinue ENDS use were invited to participate. Construct validity was examined with exploratory and confirmatory factor analyses. Instrument and factor scores were then correlated with cotinine, a biomarker of nicotine exposure., Results: All participants (n = 209) were highly dependent and co-used combustible cigarettes to varying degrees. Both instruments demonstrated content validity and construct validity, however only the 5-item Roswell eND Scale demonstrated criterion-related validity by showing a significant positive correlation with salivary cotinine levels., Conclusions: The 5-item Roswell eND Scale can briefly and effectively assess nicotine dependence among treatment-seeking adults who co-use ENDS and cigarettes. These preliminary psychometric findings have the potential to be generalizable to other adults seeking to discontinue ENDS use, many of whom currently or formerly smoked cigarettes., Competing Interests: Conflict of interest statement Jonathan Foulds has been paid for consulting for pharmaceutical companies who market smoking cessation medication including Pfizer and Johnson & Johnson. Maciej L. Goniewicz served as a member of a scientific advisory board to Johnson & Johnson and has received a research grant from Pfizer. The other authors have no potential or actual conflicts of interest to disclose., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: The e-cigarette market has rapidly evolved, with a shift towards higher nicotine concentration and salt-based products, such as JUUL ; however, the implications for youth vaping remain unclear., Methods: Repeat cross-sectional online surveys were conducted in 2017, 2018 and 2019, with national samples of youth aged 16-19 years recruited from commercial panels in Canada (n=12 018), England (n=11 362) and the USA (n=12 110). Regression models examined differences between countries and over time in the types of e-cigarette products used (design and nicotine content), reasons for using brands and differences in patterns of use, sociodemographics and dependence symptoms by brand/nicotine content., Results: In 2019, the use of pod- or cartridge-style e-cigarettes was greater in Canada and the USA than England, with Smok and JUUL the leading brands in all countries. In 2019, youth vapers in England were less likely to report using e-cigarettes with ≥2% nicotine (12.8%) compared with Canada (40.5%; adjusted OR (AOR)=4.96; 95% CI 3.51 to 7.01) and the USA (37.0%; AOR=3.99, 95% CI 2.79 to 5.71) and less likely to report using nicotine salt-based products (12.3%) compared with Canada (27.1%; AOR=2.77, 95% CI 1.93 to 3.99) and the USA (21.9%; AOR=2.00, 95% CI 1.36 to 2.95). In 2019, self-reported use of products with higher nicotine concentration was associated with significantly greater frequency of vaping, urges to vape and perceived vaping addiction (p<0.05 for all)., Conclusions: The use of high-nicotine salt-based products is associated with greater symptoms of dependence, including JUUL and other higher-nicotine brands. Greater use of high-nicotine salt-based products may account for recent increases in the frequency of vaping among youth in Canada and the USA., Competing Interests: Competing interests: DH and JT have served as paid expert witnesses in legal challenges against tobacco and vaping companies. MLG has received research grants from Pfizer and served as a member of a scientific advisory board to Johnson&Johnson. The other authors have no competing interests relevant to this article to disclose., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Flavored electronic nicotine delivery systems (ENDS) and tobacco products are associated with the initiation and progression of tobacco use. With recent restrictions around flavored products, it is critical to measure both the product and the flavor being used. The Tobacco Centers of Regulatory Science (TCORS) Flavored Tobacco Products Measurement Subcommittee (FTPMS) was established to develop core measures to assess flavored tobacco and ENDS product usage, facilitate data harmonization, replicability, and comparisons across studies., Aims and Methods: The FTPMS used a mixed-method approach to inform the development of recommended measures (first use, current use, reasons for use) to assess tobacco and ENDS product flavors. This included reviewing existing surveys, identifying priority areas, developing new measures, cognitive testing, and finalization of recommended measures., Results: Recommended measures were selected from national surveys (e.g. PATH study) and survey items used in TCORS studies to evaluate first use, current use, and reasons for use of tobacco and ENDS products. Response options were expanded for questions about specific flavors and adapted to allow for assessments relevant to recent federal policies. Supplemental measures were developed for researchers conducting more in-depth research around flavored products., Conclusions: Using an expert consensus process supplemented with cognitive testing, the FTPMS developed recommendations for core and supplemental measures for flavored tobacco and ENDS products. Harmonizing data on these factors for flavored tobacco and ENDS products are critical for researchers and may provide actionable evidence to federal, state, and local regulators and policymakers, as well as support evaluations of policies restricting flavors in these products., Implications: The development of core measures to assess first use, current use, and reasons for use of flavored tobacco and ENDS products will facilitate data harmonization, replicability, and comparisons across studies conducted in different samples or across communities with varying levels of regulation for these products. Use of these standardized measures will allow for a greater understanding of the role of flavors and helps to build a more robust evidence base to inform regulatory decisions to reduce tobacco and ENDS use at the population level., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.)

E-cigarette or vaping product use-associated lung injury (EVALI) is a severe pulmonary illness associated with the use of e-cigarettes or vaping products that was officially identified and named in 2019. This American Thoracic Society workshop was convened in 2021 to identify and prioritize research and regulatory needs to adequately respond to the EVALI outbreak and to prevent similar instances of disease associated with e-cigarette or vaping product use. An interdisciplinary group of 26 experts in adult and pediatric clinical care, public health, regulatory oversight, and toxicology were convened for the workshop. Four major topics were examined: 1 ) the public health and regulatory response to EVALI; 2 ) EVALI clinical care; 3 ) mechanisms contributing to EVALI; and 4 ) needed actions to address the health effects of EVALI. Oral presentations and group discussion were the primary modes used to identify top priorities for addressing EVALI. Initiatives including a national EVALI case registry and biorepository, integrated electronic medical record coding system, U.S. Food and Drug Administration regulation and enforcement of nicotine e-cigarette standards, regulatory authority over nontobacco-derived e-cigarettes, training in evaluating exogenous exposures, prospective clinical studies, standardized clinical follow-up assessments, ability to more readily study effects of cannabinoid e-cigarettes, and research to identify biomarkers of exposure and disease were identified as critical needs. These initiatives will require substantial federal investment as well as changes to regulatory policy. Overall, the workshop identified the need to address the root causes of EVALI to prevent future outbreaks. An integrated approach from multiple perspectives is required, including public health; clinical, basic, and translational research; regulators; and users of e-cigarettes. Improving the public health response to reduce the risk of another substantial disease-inducing event depends on coordinated actions to better understand the inhalational toxicity of these products, informing the public of the risks, and developing and enforcing regulatory standards for all e-cigarettes.

Objectives: This study presents an analysis of vaping products (VPs) purchased in the USA, Canada, England and Australia and assesses whether differences in regulations were associated with differences in the chemical composition of the VPs., Methods: April-September 2017, a total of 234 VP refill liquids and prefilled cartridges were purchased in convenience samples of retail locations in each country. Products were chosen from brands and styles most commonly reported by current VP users in the 2016 ITC Four Country Smoking and Vaping Survey. All products were tested for nicotine, tobacco-specific nitrosamines (TSNAs), minor tobacco alkaloids, organic acids and flavouring chemicals., Results: Consistent with the laws in Canada and Australia at the time of product purchase, nicotine was not detected in any of the VPs (n=10 in Canada; n=15 in Australia). US liquids (n=54) had a mean nicotine concentration of 16.2 mg/mL, (range=0.0-58.6) and English liquids (n=166) had a mean concentration of 11.9 mg/mL ((range=0.0-31.2) F(3244)=12.32, p<0.001). About 5% of English samples exceeded the UK's 20 mg/mL nicotine limit. Substantial country differences were observed in levels ofTSNAs, with the USA being higher than elsewhere. Of all products tested, 18.8% contained at least one organic acid. Liquids purchased in England contained far more identifiable flavouring chemicals than those in the other countries., Conclusions: VP composition, particularly with respect to nicotine and flavouring, varies by country, likely reflecting both marketplace preferences and country-specific regulations. There are differences between nicotine levels claimed on the package and actual levels, particularly in England., Competing Interests: Competing interests: MC and DH have each served as paid expert witnesses in legal challenges against cigarette companies. GTF has served as a paid expert witness on behalf of governments in litigation involving the tobacco industry. MLG reports research grant from Pfizer and membership in scientific advisory board to Johnson & Johnson, outside the scope of this paper., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Novel tobacco-free oral nicotine products are not combusted, easy to conceal, available in flavors, and do not contain tobacco leaf. Since 2016, oral nicotine product sales have increased and may be gaining popularity among youth. This study aims to examine the trends in the prevalence and correlates of oral nicotine product use among U.S. youth., Methods: Data from participants aged 16-19 years in the U.S. International Tobacco Control Policy Evaluation Project Youth Tobacco and Vaping Survey were analyzed cross-sectionally from August 2019, February 2020, August 2020, February 2021, and August 2021. Weighted descriptive statistics and logistic regressions were used to describe the use and correlates of oral nicotine products., Results: Oral nicotine product use significantly increased from 3.5% in August 2019 to 4.1% in August 2021. Oral nicotine product use was most prevalent among those aged 18 years, male, and non-Hispanic White. Those who used cigarettes (AOR=2.18, 95% CI=19.37, 40.88), nicotine vaping products (AOR=4.27, 95% CI=3.02, 6.04), and smokeless tobacco (AOR=28.14, 95% CI=19.37, 40.88) in the past 30 days were more likely to report recent use of oral nicotine products., Conclusions: Although oral nicotine products are less popular among U.S. youth than cigarettes, nicotine vaping products, and smokeless tobacco, their prevalence of use significantly increased. Oral nicotine product users are more likely to use other nicotine products, but the availability of flavors and easy-to-conceal design may be appealing to those who may not use nicotine products. Researchers should continue to observe the behaviors associated with oral nicotine product use to inform the need for future regulatory efforts., (© 2023 The Authors.)

Competing Interests: Competing interests: MLG reports grants from and served as an advisory board member to pharmaceutical companies that manufacture smoking cessation drugs.

Introduction: On 18 May 2020, New York State enacted legislation banning the sale of vaping products with distinguishable flavours (other than tobacco). According to this new statute, vaping products are deemed flavoured if they include a statement, whether expressed or implied, that have distinguishable tastes or aromas other than tobacco. This study aimed to determine how manufacturers responded., Methods: We collected 555 vaping products from daily vapers (238 preban and 317 postban). We compared preban and postban labelling of products for expressed and implied flavour descriptions, graphics and colours. Flavouring chemicals and concentrations were identified using chromatography methods and were compared preban and postban., Results: Analysis of the labels preban and postban did not reveal a change in products with expressed flavoured descriptors (45.8% vs 44.2%) and a minimal decrease in implied descriptors (22.3% vs 14.5%). An increase in products without any descriptors was observed (28.2% vs 37.2%) notably within products from a popular pod brand. The average concentration of eight popular flavourings identified preban was 1.4±2.7 compared with 2.3±3.5 mg/mL (p<0.001) postban. No significant changes between individual flavouring concentrations in the most popular refill solutions and pods were found., Conclusion: While a majority of products appeared to remain non-compliant, this study suggests that enactment of legislation on vaping products making expressed or implied flavour claims may result in some manufacturer changes to product labelling including removal of flavour descriptors. However, use of flavouring additives in vaping products appeared not to be impacted by the ban., Competing Interests: Competing interests: MLG reports grants from and served as an advisory board member to pharmaceutical companies that manufacture smoking cessation drugs. Other authors declare no conflict of interest., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: While risk factors for cigarette smoking among youth and young adults are well-documented, less is known about the correlates of initiation of other tobacco products. This study aims to provide estimates and correlates of initiation among U.S. youth and young adults., Methods: Data on youth aged 12-17 (n = 10,072) and young adults aged 18-24 (N = 5,727) who provided information on cigarettes, electronic nicotine delivery systems (ENDS), cigars, pipe, hookah and smokeless tobacco use in Wave 1 (W1: 2013-2014)-Wave 4 (W4: 2016-2018) of the nationally-representative PATH Study were used to calculate ever use initiation and correlates of initiation by W4., Results: Nearly 6 million youth and 2.5 million young adults used tobacco for the first time between W1-W4. Approximately one quarter of youth and young adult ENDS never users initiated ENDS between W1-W4 of the PATH Study. Among youth, use of other tobacco products, ever substance use, and high externalizing problems were associated with initiation of most products. Among young adults, use of other tobacco products and ever substance use were associated with initiation of most products. In both youth and young adults, Hispanics were more likely to initiate hookah use than their non-Hispanic White counterparts. While male sex was a risk factor for most tobacco product initiation across both age groups, it was not associated with hookah initiation., Conclusions: Cigarette and non-cigarette products shared many correlates of initiation, although there are noteworthy demographic differences. Findings can help tailor product specific interventions to reach populations at risk during preliminary stages of use., (Published by Elsevier Ltd.)

Introduction: Juul is a leading electronic cigarette (e-cigarette) brand in the USA. By November 2019, Juul pre-emptively limited online and in-store sales of non-tobacco or menthol-flavoured pods ahead of impending flavour bans. Since this removal, sale of mango-flavoured Juul-compatible pods was introduced to the market by smaller companies. The aim of this study was to compare chemical constituents of original Juul mango pods with mango-flavoured Juul-compatible pods., Methods: Juul and 16 brands of Juul-compatible mango-flavoured pods were purchased online in May 2018 (original Juul) and November 2019 (Juul-compatible), after Juul voluntarily removed their flavoured pods from the market. Liquid was extracted from pods and analysed using chromatography and mass spectrometry methods for nicotine concentration, solvent ratios, nicotine salt identification, as well as flavouring identification and quantitation., Results: Juul-compatible pods had a significantly lower average nicotine concentration compared with original Juul pod (42.8±8.9 vs 57.2±0.9 mg/mL, p<0.0001). Nicotine benzoate was used in original Juul pod and all Juul-compatible pods. The propylene glycol to vegetable glycerin volumetric ratio of Juul-compatible pods averaged 55:45, while the original Juul pod was 35:65 (p<0.0001). Total number of flavouring chemicals detected was significantly higher in Juul-compatible pods as compared with Juul (p<0.0001). In Juul-compatible pods, average concentrations of benzyl alcohol (fruity flavouring) were 0.8±1.3 mg/mL, approximately 27 times higher than in original Juul pod (p<0.0001)., Conclusions: Adulterated Juul-compatible products may expose e-cigarette consumers to more chemical constituents at higher concentrations than previously found in the original product, despite similarity in product design., Competing Interests: Competing interests: MLG reports grants from and served as an advisory board member to pharmaceutical companies that manufacture smoking-cessation drugs. Other authors declare no conflict of interest., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: We examined the relationship between current tobacco use and functionally important respiratory symptoms., Methods: Longitudinal cohort study of 16 295 US adults without COPD in Waves 2-3 (W2-3, 2014-2016) of the Population Assessment of Tobacco and Health Study. Exposure-Ten mutually exclusive categories of tobacco use including single product, multiple product, former, and never use (reference). Outcome-Seven questions assessing wheezing/cough were summed to create a respiratory symptom index; cutoffs of ≥2 and ≥3 were associated with functional limitations and poorer health. Multivariable regressions examined both cutoffs cross-sectionally and change over approximately 12 months, adjusting for confounders., Results: All tobacco use categories featuring cigarettes (>2/3's of users) were associated with higher risk (vs. never users) for functionally important respiratory symptoms at W2, for example, at symptom severity ≥ 3, risk ratio for exclusive cigarette use was 2.34 [95% CI, 1.92, 2.85] and for worsening symptoms at W3 was 2.80 [2.08, 3.76]. There was largely no increased symptom risk for exclusive use of cigars, smokeless tobacco, hookah, or e-cigarettes (adjustment for pack-years and marijuana attenuated the cross-sectional e-cigarette association from 1.53(95% CI 0.98, 2.40) to 1.05 (0.67, 1.63); RRs for these products were also significantly lower compared to exclusive use of cigarettes. The longitudinal e-cigarette-respiratory symptom association was sensitive to the respiratory index cutoff level; exclusive e-cigarette use was associated with worsening symptoms at an index cutoff ≥ 2 (RR = 1.63 [1.02, 2.59]) and with symptom improvement at an index cutoff of ≥ 3 (RR = 1.64 [1.04, 2.58])., Conclusions: Past and current cigarette smoking drove functionally important respiratory symptoms, while exclusive use of other tobacco products was largely not associated. However, the relationship between e-cigarette use and symptoms was sensitive to adjustment for pack-years and symptom severity., Implications: How noncigarette tobacco products affect respiratory symptoms is not clear; some studies implicate e-cigarettes. We examined functionally important respiratory symptoms (wheezing/nighttime cough) among US adults without COPD. The majority of adult tobacco users smoke cigarettes and have higher risk of respiratory symptoms and worsening of symptoms, regardless of other products used with them. Exclusive use of other tobacco products (e-cigarettes, cigars, smokeless, hookah) was largely not associated with functionally important respiratory symptoms and risks associated with their use was significantly lower than for cigarettes. The association for e-cigarettes was greatly attenuated by adjustment for cigarette pack-years and sensitive to how symptoms were defined., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.)

Introduction: Tobacco-free oral nicotine products are an emerging class of noncombustible nicotine products. Oral nicotine product sales have increased since 2016, although little research has investigated consumer awareness, use, or correlates of oral nicotine product use. The purpose of this analysis was to assess the prevalence and correlates of oral nicotine product awareness and use., Methods: This paper is a cross-sectional analysis of 2,507 U.S. participants from Wave 3 (February-June 2020) of the International Tobacco Control Four Country Smoking and Vaping Survey, a population-based survey of current and former cigarette smokers and nicotine vaping product users in the U.S. Oral nicotine product awareness and use prevalence were compared with those of heated tobacco products. Analyses conducted in late 2021 assessed the correlates of oral nicotine product awareness and use such as demographic characteristics, tobacco use (cigarettes, nicotine vaping products, smokeless tobacco), and tobacco quit attempts., Results: Almost 1 in 5 respondents claimed to have heard of oral nicotine products, 3.0% reported ever use, and 0.9% were current users, all of which were lower than for heated tobacco products. Ever use of oral nicotine products was more common among younger adults (e.g., aged 18-24 years), males, and current users of smokeless tobacco. Oral nicotine product prevalence was higher among those who reported having made attempts to stop smoking or vaping., Conclusions: Oral nicotine product use was low among current and former smokers and nicotine vaping product users. Oral nicotine product users were demographically similar to use among individuals who smoke/vape and also use smokeless tobacco. Future studies are needed to understand emerging oral nicotine products, particularly whether they are being used as product supplements (dual use), replacements (switching), or cessation aids (quitting)., (Copyright © 2022 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

RNA-seq is a high-throughput sequencing technology widely used for gene transcript discovery and quantification under different biological or biomedical conditions. A fundamental research question in most RNA-seq experiments is the identification of differentially expressed genes among experimental conditions or sample groups. Numerous statistical methods for RNA-seq differential analysis have been proposed since the emergence of the RNA-seq assay. To evaluate popular differential analysis methods used in the open source R and Bioconductor packages, we conducted multiple simulation studies to compare the performance of eight RNA-seq differential analysis methods used in RNA-seq data analysis (edgeR, DESeq, DESeq2, baySeq, EBSeq, NOISeq, SAMSeq, Voom). The comparisons were across different scenarios with either equal or unequal library sizes, different distribution assumptions and sample sizes. We measured performance using false discovery rate (FDR) control, power, and stability. No significant differences were observed for FDR control, power, or stability across methods, whether with equal or unequal library sizes. For RNA-seq count data with negative binomial distribution, when sample size is 3 in each group, EBSeq performed better than the other methods as indicated by FDR control, power, and stability. When sample sizes increase to 6 or 12 in each group, DESeq2 performed slightly better than other methods. All methods have improved performance when sample size increases to 12 in each group except DESeq. For RNA-seq count data with log-normal distribution, both DESeq and DESeq2 methods performed better than other methods in terms of FDR control, power, and stability across all sample sizes. Real RNA-seq experimental data were also used to compare the total number of discoveries and stability of discoveries for each method. For RNA-seq data analysis, the EBSeq method is recommended for studies with sample size as small as 3 in each group, and the DESeq2 method is recommended for sample size of 6 or higher in each group when the data follow the negative binomial distribution. Both DESeq and DESeq2 methods are recommended when the data follow the log-normal distribution., Competing Interests: The authors have declared that no competing interests exist.

Heterogeneity in the clinical presentation of SARS-CoV-2 infection and COVID-19 progression underscores the urgent need to identify individual-level susceptibility factors that affect infection vulnerability and disease severity. Tobacco product use is a potential susceptibility factor. In this Personal View, we provide an overview of the findings of peer-reviewed, published studies relating tobacco product use to SARS-CoV-2 infection and COVID-19 outcomes, with most studies focusing on cigarette smoking in adults. Findings pertaining to the effects of tobacco product use on the incidence of SARS-CoV-2 infection are inconsistent. However, evidence supports a role for cigarette smoking in increasing the risk of poor COVID-19 outcomes, including hospital admission, progression in disease severity, and COVID-19-related mortality. We discuss the potential effects of tobacco use behaviour on SARS-CoV-2 transmission and infection, and highlight the pathophysiological changes associated with cigarette smoking that could promote SARS-CoV-2 infection and increased disease severity. We consider the biological mechanisms by which nicotine and other tobacco product constituents might affect immune and inflammatory responses to SARS-CoV-2 infection. Finally, we identify current knowledge gaps and suggest priorities for research to address acute and post-acute health outcomes of COVID-19 during and after the pandemic., Competing Interests: Declaration of interests NLB reports honoraria from McGraw Hill (for a chapter on “Antihypertensive agents” in Basic and Clinical Pharmacology) and Wolters Kluwer (for a chapter on the “Cardiovascular effects of nicotine” in UpToDate), payment for expert testimony against tobacco companies, and consulting fees from Pfizer and Achieve Life Sciences. NLB and MLG were speakers at the 2017 Global Nicotine Forum; they received no reimbursement from the tobacco industry for this role and the conference received no sponsorship from tobacco companies, e-cigarette companies, or the pharmaceutical industry. MLG reports ad-hoc consultancy fees from WHO, the US Food and Drug Administration (FDA), the Campaign for Tobacco-Free Kids, the University of South Carolina, and the University of North Carolina; honoraria for lectures from the University of Rochester, Memorial Sloan Kettering Cancer Center, and the University of South Carolina; reimbursement for travel from WHO and the International Association for the Study of Lung Cancer; and consultancy fees from Johnson & Johnson. MLG has a leadership role as a member of the Tobacco Products and Cancer Subcommittee of the American Association for Cancer Research and is a member of the Tobacco Control and Cessation Committee of the International Association for the Study of Lung Cancer. SK-S is the President of the Society for Research on Nicotine and Tobacco. PML is a member of the California Tobacco Education and Research Oversight Committee. BH-F reports payment for expert testimony in e-cigarette litigations and volunteer membership on the board for Parents Against Vaping E-cigarettes. RJO'C reports consultancy fees from the National Institutes of Health, WHO, Georgetown University, and the FDA; he also reports payment from the British Medical Journal for his work as Senior Editor, and support for travel and meeting attendance from WHO, the FDA, and Georgetown University. MAP, RMR, and AB declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: Regulation of nicotine vaping products (NVPs) varies between countries, impacting the availability and use of these products. This study updated the analyses of O'Connor et al on types of NVPs used and examined changes in NVP features used over 18 months in four countries with differing regulatory environments., Design: Data are from 4734 adult current vapers in Australia, Canada, England and the USA from Waves 1 (2016) and 2 (2018) of the International Tobacco Control Four Country Smoking and Vaping Survey. NVP characteristics included device description, adjustable voltage, nicotine content and tank size. Longitudinal analyses (n=1058) assessed movement towards or away from more complex/modifiable NVPs. A logistic regression was used to examine factors associated with changes in device description from 2016 to 2018., Results: Like 2016, box-tanks were the most popular NVP (37.3%) in all four countries in 2018. Over 80% of vapers continued using the same NVP and nicotine content between waves, though movement tended towards more complex/modifiable devices (14.4% of vapers). Box-tank users, exclusive daily vapers and older vapers were most likely to continue using the same device description. Certain NVPs and features differed by country, such as higher nicotine contents in the USA (11.5% use 21+ mg/mL) and greater device stability over time in Australia (90.8% stability)., Conclusions: Most vapers continued using the same vaping device and features over 18 months. Differences in NVP types and features were observed between countries, suggesting that differing NVP regulations affect consumer choices regarding the type of vaping device to use., Competing Interests: Competing interests: AM is a UK National Institute for Health Research (NIHR) Senior Investigator. MC has received payment as a consultant to Pfizer, Inc. for service on an external advisory panel to assess ways to improve smoking cessation delivery in health care settings. MC and DH also have served as a paid expert witness in litigation filed against cigarette manufacturers. MLG has received a research grant from Pfizer and served as a member of scientific advisory board to Johnson & Johnson. DH and GTF have served as expert witnesses on behalf of governments in litigation involving the tobacco industry and vaping industry (DH)., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: The relation between respiratory symptoms and the range of tobacco product use among US adolescents/young adults is not yet clear. This cross-sectional analysis examines tobacco product use and respiratory symptoms in a nationally representative sample of 21,057 adolescents/young adults aged 12-24 years from Wave 4 (2016-17) of the Population Assessment of Tobacco and Health Study., Methods: Presence of functionally important respiratory symptoms was defined by questions regarding wheezing and nighttime cough at a cutoff score associated with poorer functional health status. Past-30-day tobacco use was analyzed 2 ways: never-tobacco users (reference) versus combustible users, noncombustible-only users, and former users; or frequency of use of cigarettes and/or e-cigarettes. Weighted Poisson regression adjusted for past-30-day marijuana use, secondhand smoke exposure, and asthma., Results: Functionally important respiratory symptoms were present in 10.0% overall: 13.8% of combustible users, 9.0% of noncombustible users, 8.2% of noncurrent users and 9.7% of never users. Functionally important respiratory symptoms were associated with combustible tobacco use (relative risk [RR] = 1.52[95% CI 1.29, 1.80]), marijuana use (RR = 1.54[1.34, 1.77]) and secondhand smoke exposure (RR = 1.04[1.03, 1.05]). Higher cigarette smoking frequency was also associated with functionally important respiratory symptoms for frequency categories >14 days/month (eg, RR = 1.93[1.50, 2.49] for 15-29 days/month). Frequency of e-cigarette use was not associated with functionally important respiratory symptoms., Conclusions: During 2016-17, smoking cigarettes, marijuana use, and secondhand smoke exposure were cross-sectionally associated with functionally important respiratory symptoms in adolescents/young adults. Risk increased with increased frequency of cigarette use but not e-cigarette use. Given changes to contemporary e-cigarettes and use, findings may not generalize to newer products., (Copyright © 2022 Academic Pediatric Association. All rights reserved.)

The health benefits of switching from tobacco to electronic cigarettes (ECs) are neither confirmed nor well characterized. To address this problem, we used RNA-seq analysis to compare the nasal epithelium transcriptome from the following groups ( n = 3 for each group): (1) former smokers who completely switched to second generation ECs for at least 6 months, (2) current tobacco cigarette smokers (CS), and (3) non-smokers (NS). Group three included one former cigarette smoker. The nasal epithelial biopsies from the EC users vs. NS had a higher number of differentially expressed genes (DEGs) than biopsies from the CS vs. NS and CS vs. EC sets (1817 DEGs total for the EC vs. NS, 407 DEGs for the CS vs. NS, and 116 DEGs for the CS vs. EC comparison). In the EC vs. NS comparison, enriched gene ontology terms for the downregulated DEGs included cilium assembly and organization, whereas gene ontologies for upregulated DEGs included immune response, keratinization, and NADPH oxidase. Similarly, ontologies for cilium movement were enriched in the downregulated DEGs for the CS vs. NS group. Reactome pathway analysis gave similar results and also identified keratinization and cornified envelope in the upregulated DEGs in the EC vs. NS comparison. In the CS vs. NS comparison, the enriched Reactome pathways for upregulated DEGs included biological oxidations and several metabolic processes. Regulator effects identified for the EC vs. NS comparison were inflammatory response, cell movement of phagocytes and degranulation of phagocytes. Disease Ontology Sematic Enrichment analysis identified lung disease, mouth disease, periodontal disease and pulmonary fibrosis in the EC vs. NS comparison. Squamous metaplasia associated markers, keratin 10, keratin 13 and involucrin, were increased in the EC vs. NS comparison. Our transcriptomic analysis showed that gene expression profiles associated with EC use are not equivalent to those from non-smokers. EC use may interfere with airway epithelium recovery by promoting increased oxidative stress, inhibition of ciliogenesis, and maintaining an inflammatory response. These transcriptomic alterations may contribute to the progression of diseases with chronic EC use.

Background: Electronic cigarettes (e-cigarettes) are relatively new tobacco products that are attracting public attention due to their unique features, especially their many flavor options and their potential as an alternative to cigarettes. However, uncertainties remain regarding the determinants and consequences of e-cigarette use because current research on e-cigarettes is made more difficult due to the lack of psychometrically sound instruments that measure e-cigarette related constructs. This systematic review therefore seeks to identify the instruments in the field that are designed to assess various aspects of e-cigarette use or its related constructs and analyze the evidence presented regarding the psychometric properties of the identified instruments., Methods: This systematic review utilized six search engines: PubMed, Medline, CINAHL, PsycINFO, Web of Science, and EMBASE, to identify articles published in the peer-reviewed journals from inception to February 2022 that contained development or validation processes for these instruments., Results: Eighteen articles describing the development or validation of 22 unique instruments were identified. Beliefs, perceptions, motives, e-cigarette use, and dependence, were the most commonly assessed e-cigarette related constructs. The included studies reported either construct or criterion validity, with 14 studies reporting both. Most studies did not report the content validity; for reliability, most reported internal consistencies using Cronbach's alpha, with 15 instruments reporting Cronbach's alpha > 0.70 for the scale or its subscales., Conclusions: Twenty-two instruments with a reported development or validation process to measure e-cigarette related constructs are currently available for practitioners and researchers. This review provides a guide for practitioners and researchers seeking to identify the most appropriate existing instruments on e-cigarette use based on the constructs examined, target population, psychometric properties, and instrument length. The gaps identified in the existing e-cigarette related instruments indicate that future studies should seek to extend the validity of the instruments for diverse populations, including adolescents. Instruments that explore additional aspects of e-cigarette use and e-cigarette related constructs to help build a strong theoretical background and expand our current understanding of e-cigarette use and its related constructs, should also be developed., (© 2022. The Author(s).)