Electronic cigarettes: an aid in smoking cessation, or a new health hazard?

Stimulus mediation, specificity and impact of menthol in rats trained to discriminate puffs of nicotine e-cigarette aerosol from nicotine-free aerosol

RATIONALE

It is unclear if e-cigarettes have reduced abuse liability relative to traditional cigarettes, especially when considering advanced devices which deliver nicotine more efficiently. Translatable and predictive animal models are needed to addresses this question.

OBJECTIVES

Our goal was to explore the subjective stimulus effects of e-cigarettes by training rats to discriminate puffs of nicotine aerosol from vehicle aerosol using an aerosol delivery system designed to model e-cigarette use patterns in humans.

METHODS

Rats were trained to discriminate between ten, 10 s puffs of aerosol generated from 3 mg/ml nicotine e-liquid and nicotine-free e-liquid using a food-reinforced operant procedure. Following acquisition, tests were conducted to determine the specificity of the nicotine aerosol stimulus as well as the impact to the stimulus effects of nicotine resulting from the addition of menthol to e-liquid.

RESULTS

Rats learned the nicotine aerosol puff vs vehicle puff discrimination in a mean of 25 training sessions. Injected nicotine fully substituted for the stimulus effects of nicotine aerosol. The stimulus effects of nicotine aerosol were blocked by the nicotinic receptor antagonist mecamylamine. The nicotinic receptor partial agonist, varenicline as well as the stimulant d-amphetamine substituted more robustly for nicotine aerosol puffs than did the NMDA antagonist, ketamine. Menthol enhanced the stimulus effects of nicotine aerosol without altering nicotine blood plasma levels.

CONCLUSIONS

Nicotine aerosol puffs can function as a training stimulus in rats. The stimulus effects were CNS-mediated and receptor specific. Menthol appears to enhance the stimulus effects of nicotine aerosol through a pharmacodynamic rather than pharmacokinetic mechanism.

Reasons for using e-cigarettes among adults who smoke: comparing the findings from the 2016 and 2020 ITC Korea Surveys

INTRODUCTION

Dual use of e-cigarettes and cigarettes is a growing usage pattern in adults, but little is known about the motivations underlying this trend. We investigated the reasons for e-cigarette use among adults who smoke, considering variation in sociodemographic subgroups.

METHODS

This repeated cross-sectional study analysed adults who smoked at least weekly and vaped at any frequency. Data were from the International Tobacco Control Korea Surveys conducted in 2016 (n=164) and 2020 (n=1088). Fourteen reasons for e-cigarette use were assessed in both waves. Subgroup analyses were performed by age, sex and educational level.

RESULTS

The top reasons for e-cigarette use in 2020 were curiosity (62.8%), less harmful than smoking (45.4%) and taste (43.2%). Curiosity was the most cited across age, sex and education subgroups. Significant differences were observed in 2020 compared with 2016, with lower percentages in goal-oriented reasons: helping quit smoking (36.3% vs 48.9%; p=0.017), helping cut down smoking (35.3% vs 52.7%; p=0.001), less harmful to others (39.0% vs 54.6%; p=0.003) and more acceptable (31.6% vs 61.2%; p<0.001). By contrast, non-goal-oriented reasons showed higher percentages in 2020, such as curiosity (62.8% vs 27.9%; p<0.001), taste (43.2% vs 22.1%; p<0.001) and enjoyment (26.8% vs 8.6%; p<0.001). In 2020, a majority of adults who smoked and vaped (53.3%) reported no intention to quit or reduce smoking.

CONCLUSIONS

E-cigarette use for curiosity and pleasure predominated among adults who smoked. The reasons for dual use in adults have shifted from goal-oriented to non-goal-oriented.

E-cigarette use among university students in Palestine: Prevalence, knowledge, and determinant factors

BACKGROUND

Recent reports indicated accelerated rates of e-cigarette use, especially among youth in various Middle Eastern countries, including Palestine. Nevertheless, little is known about knowledge, attitudes, and perceptions regarding this topic in Palestine. This study aimed to assess the prevalence of e-cigarette use among Palestinian university students, along with their knowledge, attitudes, and perceptions about e-cigarette use.

METHODS

An observational cross-sectional study, utilizing an online self-administered questionnaire, was conducted on Palestinian students from five universities between 17/04/2023 and 04/11/2023.

RESULTS

A total of 1002 Palestinian university students completed the questionnaire. The prevalence of e-cigarette use among students was 18.1%. The mean knowledge score about e-cigarettes was significantly lower among the users of e-cigarettes compared to non-users. E-cigarette use was significantly associated with the participants' smoking status. Among e-cigarette users, 43.6% were also current traditional cigarette users, and 66.9% were current waterpipe users. E-cigarette use was significantly associated with having a friend who is a smoker and/ or a smoking mother. Binary logistic regression revealed a significant positive effect between the participant's smoking status, the mother's smoking status, knowledge about e-cigarettes, and the use of e-cigarettes (p-value < 0.05). Among e-cigarette users, 18.8% used them in indoor places at the university, and 25% reported using them daily in the past month. Affordability of e-cigarettes was the most reported reason for their use (47.5%).

CONCLUSION

This study concluded that e-cigarette use is prevalent and rapidly rising among university students in Palestine. This is worrisome as it is significantly associated with insufficient knowledge about the adverse health effects of E-cigarette use, and its addictive nature. These findings focus on the importance of improving the students' knowledge about e-cigarette use by implementing educational campaigns and considering age regulations on e-cigarette availability and use.

The potential health effects associated with electronic-cigarette

A good old gateway theory that electronic-cigarettes (e-cigarettes) are widely recognized as safer tobacco substitutes. In actuality, demographics also show that vaping cannibalizes smoking, the best explanation of the data is the "common liability". However, the utilization of e-cigarette products remains a controversial topic at present. Currently, there has been a widespread and substantial growth in e-cigarette use worldwide owing to their endless new flavors and customizable characteristics. Furthermore, e-cigarette has grown widespread among smokers as well as non-smokers, including adolescents and young adults. And some studies have shown that e-cigarette users are at greater risk to start using combustible cigarettes while e-cigarettes use was also observed the potential benefits to people who want to quit smoking or not. Although it is true that e-cigarettes generally contain fewer toxic substances than combustible cigarettes, this does not mean that the chemical composition in e-cigarettes aerosols poses absolutely no risks. While concerns about toxic substances in e-cigarettes and their widespread use in the population are reasonable, it is also crucial to consider that e-cigarettes have been associated with the potential for promoting smoking cessation and the clinically relevant improvements in users with smoking-related pathologies. Meanwhile, there is still short of understanding of the health impacts associated with e-cigarette use. Therefore, in this review, we discussed the health impacts of e-cigarette exposure on oral, nasal, pulmonary, cardiovascular systems and brain. We aspire for this review to change people's previous perceptions of e-cigarettes and provide them with a more balanced perspective. Additionally, we suggest appropriate adjustments on regulation and policy for e-cigarette to gain greater public health benefits.

Comparison of brain nicotine accumulation from traditional combustible cigarettes and electronic cigarettes with different formulations

Rapid brain accumulation is critical for the acute reinforcing effects of nicotine. Although nicotine formulation (free-base vs. protonated or salt) in electronic cigarette (E-cig) liquid affects user satisfaction, its impact on brain nicotine accumulation (BNA) from E-cig use has not been evaluated in comparison with traditional combustible cigarettes (C-cigs) using a within-subjects design. BNA was directly assessed with 29 adult dual users (13 females) of E-cigs and C-cigs, using [11C]nicotine and positron emission tomography (PET). Participants underwent two 15-min upper body (from chest to head) scanning sessions during which they inhaled a single puff of [11C]nicotine-labeled vapor from E-cigs with free-base nicotine or C-cig smoke in a randomized order. Seventeen of them also went through another session during which they inhaled from E-cigs with nicotine salt. A full-body scan was also conducted at each session to measure total absorbed dose of [11C]nicotine. Mean maximum nicotine concentration (Cmax) in brain following inhalation of free-base nicotine E-cig vapor was 19% and 15% lower relative to C-cig smoke and nicotine salt E-cig vapor (ps = 0.014 and 0.043, respectively). The Cmax values did not differ significantly between the C-cig and nicotine salt E-cig. Mean values of time to the maximum concentration (Tmax) were not significantly different between the two types of E-cig, but they were 64% and 40% longer than that for C-cig smoking (ps = 0.0005 and 0.004, respectively). Mean Cmax with C-cigs and free-base nicotine E-cigs were greater in females relative to males and correlated with T1/2 of lung nicotine clearance and participants' pack-years. These results suggest that while E-cigs with free-base nicotine formulation can deliver nicotine rapidly to the brain, those with nicotine salt formulation are capable of even more efficient brain nicotine delivery closely resembling combustible cigarettes. Therefore, nicotine formulation or pH in E-liquid should be considered in evaluation of E-cigs in terms of abuse liability and potential in substituting for combustible cigarettes.

Patterns of flavored e-cigarette use among adult vapers in the USA: an online cross-sectional survey of 69,233 participants

BACKGROUND

Flavored e-cigarettes remain a controversial topic with regulators planning or already implementing restrictions worldwide. In this study, we examined patterns of flavor use in e-cigarettes among a convenience sample of US adult vapers.

METHODS

Participants aged ≥ 18 years who reported ever using an e-cigarette were included in the study (N = 69,233) and responded to an online questionnaire. Their smoking status was recorded as well as patterns of flavor use at e-cigarette use initiation, at the time of the survey and at the time of smoking cessation (for participants who used to smoke and were using e-cigarettes at the time of quitting).

RESULTS

The most popular flavors at e-cigarette use initiation were fruit (82.8%), followed by dessert/pastry/bakery (68.6%) and candy/chocolate/sweet (52.2%). Slightly higher prevalence of using fruit and dessert/pastry/bakery flavors was observed in those who never smoked compared to those who were currently and formerly smoking. Tobacco flavors were used by 20.8% of the participants and was by far the least prevalent among participants who never smoked. Similar patterns were observed with participants' choices at the time of the survey, but tobacco flavor use was substantially reduced (7.7%). Only 2.1% reported tobacco as the single most often used flavor. The most prevalent flavor at the time of quitting smoking was again fruit (83.3%), followed by dessert/pastry/bakery (68.0%) and candy/chocolate/sweet (44.5%). These flavors were considered the most helpful for quitting smoking. Tobacco flavor use at the time of smoking cessation was reported by 15.0%, while 9.3% considered it helpful for quitting smoking.

CONCLUSION

Non-tobacco flavors were popular among the US adult vapers who participated in the study, and were popular choices at the time of quitting smoking for those who formerly smoked. Tobacco flavor use prevalence was low and was further reduced over time. Regulators should consider the flavor choice of adult consumers, especially those who quit smoking, when preparing legislation on flavored e-cigarettes.

Motives for using electronic nicotine delivery systems (ENDS) as a cessation tool are associated with tobacco abstinence at 1-year follow-up: A prospective investigation among young adults in the United States Air Force

Introduction

Smokers use electronic nicotine delivery systems (ENDS), including e-cigarettes, as a harm reduction strategy even though the Food and Drug Administration (FDA) has not approved them for tobacco cessation. The limited literature about ENDS use for cigarette cessation is concerning for the U.S. military, which is largely comprised of young adults at increased risk for tobacco use. Thus, the current study aims to evaluate use of ENDS products as a cessation tool in relation to point-prevalence tobacco abstinence at one-year follow-up in a cohort of 8,901 U.S. Air Force personnel attending entry-level job training from March 2016 to April 2019.

Methods

A propensity-score adjusted multinomial logistic regression model was used to assess the association between the baseline motives for ENDS use (i.e., for cigarette cessation versus alternative reasons) and tobacco use at the one-year follow-up (cigarette use, non-cigarette tobacco product use, and tobacco abstinence) among those reporting history of cigarette use at baseline.

Results

Smokers reporting ENDS use for cigarette cessation were more likely to be abstinent at one-year follow-up (Odds Ratio[OR] = 1.62, 95% CI: 1.06-2.49, P =.03) as well as quit using non-cigarette tobacco products (OR = 2.11, 95% CI: 1.65-2.70, P <.001) than those reporting ENDS use for alternative reasons.

Conclusions

Current tobacco users are recommended to use FDA-approved products for smoking cessation, such as nicotine replacement therapy. However, given the high prevalence of cigarette use among military populations, ENDS may provide a useful alternative harm reduction strategy for this high-risk population.

Misconceptions of Vaping Among Young Adults

Background Vaping is growing in popularity worldwide, especially among young adults. To develop effective tobacco prevention interventions, first, there must be an understanding of the attitudes and perceptions of young adults toward the use of vaping. Highlighting perception discrepancies between races may allow physicians to more effectively counsel their patients regarding the risks of vaping. Methodology We conducted an online survey using Amazon Mechanical Turk (MTurk, https://www.mturk.com/) to identify misconceptions about vaping among adults aged 18 to 24 years who currently vape. The survey consisted of 18 questions evaluating reasons for vaping, history of tobacco use, and thoughts on the adverse effects of vaping. The Penn State Electronic Cigarette Dependence Index was implemented to assess dependence. Exclusion criteria comprised respondents who did not vape and were under the age of 18 or over the age of 24. Results A total of 1,009 responses were received with 66% identifying as male (n = 667) and 33% (n = 332) identifying as female. Sixty-nine percent of patients smoked cigarettes or used another form of tobacco previously (n = 692). Of those respondents, 81% indicated that they had since quit using tobacco products (excluding vaping). Switching to vaping was the most common reason for quitting cigarettes or other forms of tobacco, with health concerns and social purposes being the second and third most common reasons provided, respectively. When asked whether vaping had negative health impacts, only 238 (24%) participants strongly agreed with this statement, while a majority (64%) neither agreed nor disagreed or only somewhat agreed. Most participants were white or Caucasian (n = 777). When asked whether smoking or vaping had more severe health implications, 55% of white or Caucasian participants, 41% of Asian participants, and 32% of black or African American participants indicated that vaping was worse than smoking cigarettes. The average Penn State dependence score was 8.7, suggesting medium dependence. Conclusions Our survey sample of 1,006 young adults who vape indicated that the majority did not perceive vaping as significantly harmful. A comprehensive smoking prevention policy, educational interventions, and quit support are needed to enhance awareness among young adults about the health effects associated with vaping. Such interventions should also consider the novel shift toward the replacement of smoking with vaping.

Comparison of brain nicotine uptake from electronic cigarettes and combustible cigarettes

Brain accumulation rate and magnitude are critical for the acute reinforcing effects of nicotine. Despite electronic cigarettes' (E-cigs) appeal as substitutes for traditional combustible cigarettes (C-cigs), brain nicotine accumulation (BNA) from E-cigs has not been compared with that from C-cigs using a within-subjects design. BNA was directly assessed with 16 adult dual users (10 females) of E-cigs (e-liquid pH 9.4) and C-cigs, using 11C-nicotine and positron emission tomography (PET). Participants went through two 15-min head scanning sessions during which they inhaled a single puff of E-cig vapor or C-cig smoke containing 11C-nicotine in a randomized order. A full-body scan was also conducted at each session to measure total absorbed dose of 11C-nicotine. Mean maximum concentration (Cmax) and area under curve of BNA were 22.1% and 22.7% lower, respectively, following E-cig compared with C-cig inhalation. Meanwhile, T1/2 was 2.7 times longer following inhalation of E-cig vapor relative to C-cig smoke (all ps < 0.005). Whole-body imaging indicated greater nicotine retention in the respiratory tract from vapor versus smoke inhalation (p < 0.0001). Following vapor inhalation, nicotine retention in the respiratory tract was correlated with Cmax values of BNA (rs = -0.59, p < 0.02). Our results confirm that E-cigs with alkaline pH e-liquid can deliver nicotine rapidly to the brain, albeit less efficiently than C-cigs partly due to greater airway retention of nicotine. Since brain nicotine uptake mediates reinforcement, these results help elucidate actions of E-cigs in terms of abuse liability and effectiveness in substituting for combustible cigarettes.

The Impact of Tobacco Cigarettes, Vaping Products and Tobacco Heating Products on Oxidative Stress

Cells constantly produce oxidizing species because of their metabolic activity, which is counteracted by the continuous production of antioxidant species to maintain the homeostasis of the redox balance. A deviation from the metabolic steady state leads to a condition of oxidative stress. The source of oxidative species can be endogenous or exogenous. A major exogenous source of these species is tobacco smoking. Oxidative damage can be induced in cells by chemical species contained in smoke through the generation of pro-inflammatory compounds and the modulation of intracellular pro-inflammatory pathways, resulting in a pathological condition. Cessation of smoking reduces the morbidity and mortality associated with cigarette use. Next-generation products (NGPs), as alternatives to combustible cigarettes, such as electronic cigarettes (e-cig) and tobacco heating products (THPs), have been proposed as a harm reduction strategy to reduce the deleterious impacts of cigarette smoking. In this review, we examine the impact of tobacco smoke and MRPs on oxidative stress in different pathologies, including respiratory and cardiovascular diseases and tumors. The impact of tobacco cigarette smoke on oxidative stress signaling in human health is well established, whereas the safety profile of MRPs seems to be higher than tobacco cigarettes, but further, well-conceived, studies are needed to better understand the oxidative effects of these products with long-term exposure.

Understanding the role of e-cigarette use in smoking cessation based on the stages of change model

Objective

We explored the role of e-cigarette use in smoking cessation based on the stages of change (SOC) model, which is a framework for describing the process of smoking cessation.

Methods

We used nationwide, cross-sectional data on adults (19+ years) from the seventh Korea National Health and Nutrition Examination Survey (KNHANES, 2016–2018) and restricted the participants to 3,929 recent smokers, consisting of current smokers and recent quitters (≤2 years). A multinomial logistic regression analysis was performed to reveal the relationships between e-cigarette use and cigarette quitting behaviors (e.g., current quitting status, past quit attempts, intention to quit, and duration of quitting) and all stages in smoking cessation, with adjustment for sociodemographic and smoking-related factors.

Results

E-cigarette use was positively related to past quit attempts, while not having quit, intention to quit, and longer duration of quitting. Based on the cessation stages, current and former e-cigarette users were significantly more likely to be in the ‘Precontemplation’ and ‘Contemplation’ stages than never users, while not to be in the ‘Preparation’ and ‘Action’ stages. Current users were particularly less likely to be in the ‘Maintenance’ stage compared to never users.

Conclusion

E-cigarette use was closely linked with early-stage behavior than late-stage behavior in the smoking cessation process. E-cigarettes might promote quit attempts and short-term quitting in some smokers, but the negative role of inducing smokers to continue cigarette smoking with no immediate quit-intention for future attempts is dominant in the real world.

E-Cigarette Markets and Policy Responses in Southeast Asia: A Scoping Review

BACKGROUND

The global e-cigarette market has proliferated and is increasingly dominated by transnational tobacco companies. While Southeast Asian countries have received relatively little attention in e-cigarette research, the region represents an area of potentially untapped growth for the industry. We review the e-cigarette situation in Southeast Asia in terms of the e-cigarette markets, advertising and promotion of e-cigarettes, reported health impacts of e-cigarette use, and policy responses in the region.

METHODS

We examined e-cigarette market data from the Euromonitor Global Market Information Database (GMID) Passport database, searched in the academic literature, grey literature and news archives for any reports or studies of e-cigarette related diseases or injuries, e-cigarette marketing, and e-cigarette policy responses in Southeast Asian countries, and browsed the websites of online e-cigarette retailers catering to the region's active e-cigarette markets.

RESULTS

In 2019, e-cigarettes were sold in six Southeast Asian markets with a total market value of $595 million, projected to grow to $766 million by 2023. E-commerce is a significant and growing sales channel in the region, with most of the popular or featured brands in online shops originating from China. Southeast Asian youth are targeted with a wide variety of flavours, trendy designs and point of sale promotions, and several e-cigarette related injuries and diseases have been reported in the region. Policy responses vary considerably between countries, ranging from strict bans to no or partial regulations.

CONCLUSION

Although Southeast Asia's e-cigarette market is relatively nascent, this is likely to change if transnationals invest more heavily in the region. Populous countries with weak e-cigarette regulations, notably Indonesia, Malaysia, Vietnam and the Philippines, are desirable targets for the transnationals. Regulatory action is needed to prevent e-cigarette use from becoming entrenched into these societies, especially among young people.

E-Cigarette Aerosol Deposition and Disposition of [11C]Nicotine Using Positron Emission Tomography: A Comparison of Nicotine Uptake in Lungs and Brain Using Two Different Nicotine Formulations

Smoking is a cause of serious disease in smokers. Electronic cigarettes, delivering aerosolized nicotine, offer adult smokers a potentially less harmful alternative to combustible cigarettes. This explorative PET/CT study investigated the distribution and deposition of inhaled [¹¹C]nicotine using the myblu^TM e-cigarette with two nicotine formulations, freebase and lactate salt. Fifteen healthy adult smokers participated in the two-part study to assess the distribution and accumulation of [¹¹C]nicotine in the respiratory pathways and brain. Time-activity data for the respiratory pathways, lungs, oesophagus and brain were derived. 31–36% of both inhaled tracer formulations accumulated in the lung within 15–35 s. [¹¹C]Nicotine_freebase exhibited higher uptake and deposition in the upper respiratory pathways. For [¹¹C]nicotine_lactate, brain deposition peaked at 4–5%, with an earlier peak and a steeper decline. A different kinetic profile was obtained for [¹¹C]nicotine_lactate with lower tracer uptake and accumulation in the upper respiratory pathways and an earlier peak and a steeper decline in lung and brain. Using nicotine lactate formulations in e-cigarettes may thus contribute to greater adult smoker acceptance and satisfaction compared to freebase formulations, potentially aiding a transition from combustible cigarettes and an acceleration of tobacco harm reduction initiatives.

E-cigarette use among Hispanics: Reducing risk or recruiting new tobacco users?

The prevalence of cigarette smoking in the United States has been declining for over 50 years among all racial/ethnic groups. However, this progress could be stalled or even reversed by the increasing popularity of electronic cigarettes (e-cigarettes). Hispanics have experienced tobacco-related health disparities resulting from early age of cigarette smoking initiation and less success in quitting smoking. The effects of e-cigarettes on tobacco-related health disparities among Hispanics have not been well described. The uptake of e-cigarettes among Hispanic youth could lead to a "tipping point" phenomenon, in which Hispanics disproportionately become nicotine-dependent in adolescence and suffer increased tobacco-related disease in adulthood. Hypothetically, if Hispanic adult cigarette smokers switch to e-cigarettes, they could reduce (but not completely eliminate) their health risks. This article summarizes the research on the use of e-cigarettes among Hispanics. We describe the prevalence and patterns of e-cigarette use among Hispanic adolescents and adults compared with non-Hispanic whites. Findings indicate that e-cigarette use is rare among Hispanic adults, but Hispanic adolescents are at risk of experimenting with e-cigarettes at early ages, potentially leading to early nicotine addiction and exacerbating tobacco-related disparities in the future. Health education and policy interventions are needed to prevent e-cigarette use among Hispanic adolescents, while acknowledging that some Hispanic adult cigarette smokers may benefit from switching to e-cigarettes.

A thematic analysis of smokers' and non-smokers' accounts of E-cigarettes

This study explored smokers' and non-smokers' accounts of E-cigarettes. A total of 51 UK-based participants, 20 men and 31 women, responded to open-ended questions online. Inductive thematic analysis identified that the factors that influence E-cigarette behaviour and opinion in adult smokers and non-smokers are related to social context, informative sources, practical aspects and health implications. Participants presented varying accounts of E-cigarettes, suggesting that individual narratives regarding E-cigarettes are multi-faceted. This is important information for health professionals and policy makers tasked with advising on E-cigarette use.

How do colleges communicate about E-cigarettes? The presentation of risk, policy, and cessation resources on college websites

ObjectivesWe examine colleges' current practices for communicating about e-cigarettes in terms of risk, campus policy, and cessation resources based on the American College Health Association (ACHA)'s and other tobacco-free campus policy guidelines. Methods: Websites of 581 universities prohibiting e-cigarette use on campus were analyzed. The relationship between the presence of e-cigarette information and campus characteristics was examined. Results: There was a lack of e-cigarette risk information. Health and other risks of e-cigarette use were rarely or never mentioned. One fifth did not specify e-cigarettes to be prohibited. While many colleges were promoting the health benefit of a tobacco-free policy, the financial/professional benefits were rarely mentioned. Less than half mentioned on-campus tobacco cessation resources and less than one third listed off-campus resources. A few campus characteristics (e.g., the U.S. census region of campus, campus housing, funding type) were associated with presence of e-cigarette information on websites. Conclusion: Our findings suggest the need for colleges to make e-cigarette risk, policy, and cessation information more accessible via official college websites for students and other campus members. This may increase students' support for vape-free policy and assist successful adoption of complete tobacco-free policies on campus.

Electronic cigarette use and smoking cessation in cohort studies and randomized trials: A systematic review and meta-analysis

INTRODUCTION

The aim of this systematic review and meta-analysis was to assess the association between e-cigarette use and subsequent smoking cessation in cohort studies and randomized controlled trials (RCT).

METHODS

A systematic literature search was finalized 11 November 2019 using EMBASE, Cochrane Library, Scopus, PubMed Health, NICE evidence search, PROSPERO, CRD, PsycInfo, and PubMed including Medline. Inclusion criteria were: reporting empirical results; longitudinal observational design with a minimum of 3 months of follow-up; including general population samples; and allowing for comparison between users and non-users of e-cigarettes. Studies rated as having high risk of bias were excluded. The procedures described by PRISMA were followed, and the quality of evidence was rated using GRADE.

RESULTS

Twenty-eight longitudinal, peer-reviewed publications from 26 cohort studies, and eight publications from seven RCTs assessing the association between e-cigarette use and smoking cessation were included in this review. A random-effects meta-analysis based on 39147 participants in cohort studies showed a pooled unadjusted odds ratio (OR) for smoking cessation among baseline e-cigarette users compared with baseline non-users of 0.97 (95% CI: 0.67-1.40), while the adjusted OR was 0.90 (95% CI: 0.63-1.27). The pooled odds ratio for smoking cessation in RCTs was 1.78 (95% CI: 1.41-2.25). The evidence for cohort studies was graded as very low and for RCTs as low.

CONCLUSIONS

We did not find quality evidence for an association between e-cigarette use and smoking cessation. Although RCTs tended to support a more positive association between e-cigarette use and smoking cessation than the cohort studies, the grading of evidence was consistently low.

Modification of the Peripheral Olfactory System by Electronic Cigarettes

Electronic cigarettes (e-cigs) are used by millions of adolescents and adults worldwide. Commercial e-liquids typically contain flavorants, propylene glycol, and vegetable glycerin with or without nicotine. These chemical constituents are detected and evaluated by chemosensory systems to guide and modulate vaping behavior and product choices of e-cig users. The flavorants in e-liquids are marketing tools. They evoke sensory percepts of appealing flavors through activation of chemical sensory systems to promote the initiation and sustained use of e-cigs. The vast majority of flavorants in e-liquids are volatile odorants, and as such, the olfactory system plays a dominant role in perceiving these molecules that enter the nasal cavity either orthonasally or retronasally during vaping. In addition to flavorants, e-cig aerosol contains a variety of by-products generated through heating the e-liquids, including odorous irritants, toxicants, and heavy metals. These harmful substances can directly and adversely impact the main olfactory epithelium (MOE). In this article, we first discuss the olfactory contribution to e-cig flavor perception. We then provide information on MOE cell types and their major functions in olfaction and epithelial maintenance. Olfactory detection of flavorants, nicotine, and odorous irritants and toxicants are also discussed. Finally, we discuss the cumulated data on modification of the MOE by flavorant exposure and toxicological impacts of formaldehyde, acrolein, and heavy metals. Together, the information presented in this overview may provide insight into how e-cig exposure may modify the olfactory system and adversely impact human health through the alteration of the chemosensory factor driving e-cig use behavior and product selections. © 2021 American Physiological Society. Compr Physiol 11:2621-2644, 2021.

New Zealand Youth19 survey: vaping has wider appeal than smoking in secondary school students, and most use nicotine-containing e-cigarettes

OBJECTIVE

To investigate smoking and vaping in secondary school students (aged 13-18 years) in New Zealand (NZ) following the introduction of 'pod' e-cigarettes, which have been associated with the rapid escalation of youth vaping elsewhere.

METHODS

Data on smoking and vaping were collected in 2019 as part of a comprehensive youth health survey (N=7,721).

RESULTS

Vaping was 2-3 times more prevalent than smoking, with 10% of students vaping regularly (monthly or more often), and 6% weekly or more often, compared with 4% and 2%, respectively, for tobacco smoking. Nicotine-containing e-cigarettes were sometimes or always used by 80% of regular and 90% of weekly vapers. Regular and weekly smoking was rare in low deprivation (affluent) areas, whereas regular and weekly vaping prevalence was similar across the socioeconomic spectrum. More than 80% of ever-vapers (N=2732) reported they were non-smokers when they first vaped, and 49% of regular vapers (N=718) had never smoked.

CONCLUSIONS

A significant proportion of New Zealand adolescents, many of whom have never smoked, use nicotine-containing e-cigarettes regularly. Implications for public health: Vaping is less harmful than smoking, but it is not harmless. Public health action is needed to support young non-smokers to remain smokefree and vape-free.

The Effects of Self vs. Group Affirmation and Message Framing on College Students' Vape-Free Campus Policy Support

A growing number of American colleges and universities have become vape-free campuses in response to the high e-cigarette use prevalence among young adults. However, little is known about communication or social-psychological factors associated with campus members' support for a tobacco policy prohibiting e-cigarette use on the campus (vape-free policy support). The present study explores the main and interaction effects of affirmation and message framing on the vape-free policy support among college students who vary in their vaping status. We conducted a computer-based experiment with a two (affirmation: self vs. group) by two (message framing: gain vs. loss) by two (vaping status: vapers vs. non-vapers) between-subjects design. Our analysis indicated that self-affirmation is associated with a higher level of vape-free policy support than group-affirmation. The main effects of message framing as well as two-way interactions between framing and affirmation were not statistically significant. A notable finding was the three-way interaction effect among affirmation, framing, and vaping status. For vapers, the level of policy support was the highest when they were self-affirmed and exposed to a gain-framed message. For non-vapers, the level of policy support was the highest when they were self-affirmed and exposed to a loss-framed message. Our findings suggest that colleges may use varied approaches in communicating a vape-free campus policy based on the target students' vaping status, and the group-pride or collective identity appeals may not be effective in promoting such policy.

Association between electronic cigarette use and fragility fractures among US adults

Background

The popularity of electronic cigarette (e-cigarette) use continues to rise in the United States. While conventional cigarette smoking is an established risk factor for osteoporosis and osteoporotic fracture, the effects of e-cigarette use on bone health are unknown. We aimed to examine the association between e-cigarette use and fragility fractures.

Research Design and Methods

We pooled 2017-2018 data from the National Health and Nutrition Examination Survey (NHANES). We included men and women with complete information on key variables. E-cigarette use was categorized as either never or ever users. Ever users were further classified as former and current users. Fragility fracture was defined as a composite of self-reported fracture of the hip, spine or wrist which resulted from minimal trauma such as a fall from standing height or less.

Results

Of 5569 participants, there were 4519 (81.2%) never e-cigarette users, 1050 (18.8%) ever e-cigarette users, and 444 (8.0%) with self-reported fragility fracture. In adjusted models, ever e-cigarette users had a 46% higher prevalence of self-reported fragility fractures compared to never users (aPR: 1.46, 95% CI: 1.12, 1.89). We also observed a higher prevalence of fragility fractures among former and current e-cigarette users compared to never users (aPR: 1.89, 95% CI: 1.44, 2.48 and aPR: 1.77, 95% CI: 1.04, 3.02 respectively).

Conclusion

E-cigarette use was associated with a higher prevalence of self-reported fragility fracture. These findings suggest that e-cigarette use may be harmful to bone health. These data highlight the critical need for longitudinal studies exploring the potential effect(s) of e-cigarette use on bone health.

A pilot investigation of e-cigarette use and smoking behaviour among patients with chronic airway disease or respiratory symptoms

Background

This pilot study aimed to investigate the current status of e‐cigarettes (ECs) use patterns among patients with chronic airway disease or chronic respiratory symptoms and the effects of ECs use on respiratory and mental health.

Methods

A cross‐sectional survey was conducted at the outpatient clinic of eight teaching hospitals in South Korea between November 2019 and December 2019. All adult ECs users (19 years and above) who visited the outpatient clinic as a patient with chronic airway disease or chronic respiratory symptoms were eligible to participate in this study.

Results

A total of 51 subjects responded to the survey. Most of the participants were male (92.2%) and the mean age was 41.8 years. Dominant airway diseases were asthma and chronic obstructive pulmonary disease. Most of the subjects had a history of cigarette smoking, and 19 subjects were dual users of current cigarettes and ECs. Most of the subjects started ECs use due to health‐related reasons. When comparing exclusive ECs users and dual users, St. George's respiratory questionnaire (SGRQ) scores, the proportion of cases with moderate to severe depressive symptoms, and average Fagerstrom test for nicotine dependence scores for ECs were higher in dual users than exclusive ECs users (mean 4.64 vs. 2.38, p = 0.006), respectively.

Conclusion

Most of the subjects started ECs use due to health concerns, but dual users have more respiratory symptoms and higher nicotine dependence in this pilot study. One hypothesis that comes from these results is that greater nicotine dependence may influence behaviours, habits, and views about ECs. These preliminary observations need confirmation in a large cohort.

Toxicological interaction between tobacco smoke toxicants cadmium and nicotine: An in-vitro investigation

Cigarettes and other tobacco products are used to obtain nicotine that is responsible for their stimulating effects. However, a lot of other organic and inorganic chemicals are also released along with nicotine. Cadmium (Cd) is one of the several heavy metals that are health hazards and is one of the inorganic elements released in tobacco smoke. The in-vitro investigation focused on exploring the effects of nicotine hydrogen tartrate (NHT) and cadmium (Cd) and their toxic interactions in the A549 cell line. In cell viability assay NHT exhibited its IC50 at 11.71 mM concentration, and the IC50 of Cd was found to be 83 µM after a 24 h exposure. Toxic effects of NHT (5 mM and 10 mM), Cd (50 µM and 100 µM), and their combination were also investigated by flowcytometry. The investigation included apoptotic and necrotic events, the effect on different cell cycle phases, and generation of reactive oxygen species by NHT, Cd, and their combination of different concentrations. Data reveal evident toxic effects of NHT, Cd, and NHT + Cd. It also indicates that the toxic interaction of NHT and Cd is not additive and appears to be minimal when compared with NHT or Cd exposures alone.

An investigation of factors encouraging and deterring EC use: a thematic analysis of accounts from UK adults

OBJECTIVE

This study aimed to explore E-cigarette (EC) accounts from a small sample of UK adults with varied smoking/EC experiences. This was to contribute to existing knowledge of adult perceptions and understand the factors that encourage or deter use to inform health messaging aimed at professionals, policy makers and the general public.

DESIGN

Twelve participants, five men and seven women aged 23-55 years (mean age 32.43) with mixed smoking/EC backgrounds took part in face-to-face interviews, analysed using semantic-level inductive thematic analysis.

RESULTS

The analysis identified three key themes. Social influence (1) relates to the understanding of the social representations of ECs. Representation and knowledge (2) captures the impact of varied EC related communication on perception. Aspects of addiction (3) conveys aspects of nicotine addiction and how this influences EC use.

CONCLUSION

ECs were generally perceived as more socially acceptable than cigarettes by non-smokers, although there were varying levels of acceptability depending on the type of EC device used. There was also unanimity concerning uncertainty surrounding the devices. Behavioural/sensory elements and personal enjoyment of ECs were consistent elements that encouraged or deterred use. Although non-smokers/vapers did not use the devices, they expressed similar apprehensions to those who did.

The consequential impact of JUUL on youth vaping and the landscape of tobacco products: The state of play in the COVID-19 era

JUUL is a groundbreaking electronic cigarette (e-cig) and the preeminent vaping product on the market. We present an overview of the rapid and spectacular rise of JUUL and its remarkable fall within the timespan of 2015 - 2020. We highlight JUUL's entering the market in June 2015, becoming the industry leader in mid 2017, and experiencing a litany of setbacks by late 2019 through to early 2020. We address the role played by JUUL in the ongoing epidemic of youth vaping. We also feature competing views on the public health impact of JUUL use (in particular), and e-cig vaping (in general). We further highlight the latest trends in youth vaping and sales records for JUUL and tobacco cigarettes. In view of the ongoing pandemic of COVID-19, we briefly summarize the existing evidence on the relationship between vaping and smoking and the prevalence, disease course, and clinical outcomes of COVID-19.

Association of e-cigarette advertising with e-cigarette and cigarette use among US adults

AIMS

To estimate the association of e-cigarette advertisement exposure with e-cigarette and cigarette use behavior among US adults.

DESIGN

Data from the 2013-14 National Adult Tobacco Survey (NATS) were linked to Kantar Media and National Consumer Study data to construct measures of e-cigarette advertisements on TV and in magazines. The relationship between advertisement measures and outcomes was estimated using logistic and Poisson regressions, controlling for socio-demographics, state cigarette taxes and state and year fixed-effects.

SETTING

United States.

PARTICIPANTS/CASES

A total of 98 746 adults aged ≥ 18 years who responded to the 2013-14 NATS.

MEASUREMENTS

The independent variables of interest were the number of e-cigarette advertisements in magazines to which an adult was exposed in the past 6 months and the number of e-cigarette advertisements on TV to which an adult was exposed in the past 6 months. Outcomes were awareness of e-cigarettes, ever e-cigarette use, current e-cigarette use, current cigarette use and number of cigarettes smoked per month.

FINDINGS

Exposure to one additional e-cigarette advertisement on TV was associated with a 0.18, 0.13 and 0.03 percentage point increase, respectively, in awareness, ever use and current use of e-cigarettes among all adults (P < 0.05). This exposure also was associated with a 0.11 percentage point increase in current cigarette use among all adults and an increase in cigarette consumption of 2.24 cigarettes per month among adults aged ≥ 45 (P < 0.05).

CONCLUSIONS

Exposure to e-cigarette advertising appears to be positively associated with the use of e-cigarettes and cigarettes among adults of all ages, and with increased cigarette consumption among older adults.

E-cigarette use and combustible tobacco cigarette smoking uptake among non-smokers, including relapse in former smokers: umbrella review, systematic review and meta-analysis

OBJECTIVE

To review and summarise the current evidence on the uptake of combustible cigarette smoking following e-cigarette use in non-smokers-including never-smokers, people not currently smoking and past smokers-through an umbrella review, systematic review and meta-analysis.

DESIGN

Umbrella review, systematic review and meta-analysis.

DATA SOURCES

PubMed, Scopus, Web of Science, PsychINFO (Ovid), Medline (Ovid) and Wiley Cochrane Library up to April 2020.

RESULTS

Of 6225 results, 25 studies of non-smokers-never, not current and former smokers-with a baseline measure of e-cigarette use and an outcome measure of combustible smoking uptake were included. All 25 studies found increased risk of smoking uptake with e-cigarette exposure, although magnitude varied substantially. Using a random-effects model, comparing e-cigarette users versus non-e-cigarette users, among never-smokers at baseline the OR for smoking initiation was 3.25 (95% CI 2.61 to 4.05, I2 85.7%) and among non-smokers at baseline the OR for current smoking was 2.87 (95% CI 1.97 to 4.19, I2 90.1%). Among former smokers, smoking relapse was higher in e-cigarette users versus non-users (OR=2.40, 95% CI 1.50 to 3.83, I2 12.3%).

CONCLUSIONS

Across multiple settings, non-smokers who use e-cigarettes are consistently more likely than those avoiding e-cigarettes to initiate combustible cigarette smoking and become current smokers. The magnitude of this risk varied, with an average of around three times the odds. Former smokers using e-cigarettes have over twice the odds of relapse as non-e-cigarettes users. This study is the first to our knowledge to review and pool data on the latter topic.

PROSPERO REGISTRATION NUMBER

CRD42020168596.

What should every dental health professional know about electronic cigarettes?

Electronic cigarettes (E-cigarettes) have become increasingly popular around the world. Currently, dental professionals' knowledge and attitudes are varied with many clinicians unclear regarding the impact of E-cigarette products on the oral and general health of their patients. With developing social and health-related challenges, advice of dental and medical associations and other regulatory bodies on E-cigarette use is changing. Growing evidence demonstrating the risks of E-cigarette usage has prompted a review of legislation in the United Kingdom (UK), United States of America (USA), Australia and Canada to include the sale and availability of E-cigarettes, particularly those containing nicotine. Further consideration within the scientific and public health community is being given to assessing demographic usage patterns particularly uptake by non-smokers and adolescents, efficacy as a cessation tool, the impact of vapour on bystanders and direct injuries via explosions as well as emerging lung injuries. This article aims to provide a summary of the most up to date evidence relating to E-cigarette use, the latest position of dental associations and the oral health implications of E-cigarettes compared to conventional smoking. The article also aims to collate this information in order to provide dental clinicians with guidance on how to advise patients, specifically in answering common questions posed regarding E-cigarette use.

5-HT2A and 5-HT2C receptors as potential targets for the treatment of nicotine use and dependence

Nicotine use and dependence, typically achieved through cigarette smoking, but increasingly through vape products, is the leading cause of preventable death today. Despite a recognition that many current smokers would like to quit, the success rate at doing so is low and indicative of the persistent nature of nicotine dependence and the high urge to relapse. There are currently three main forms of pharmacotherapy approved as aids to treat nicotine dependence: a variety of nicotine replacement products (NRT's), the mixed NA/DA reuptake inhibitor bupropion (Zyban®), and the preferential nicotinic α4β2 receptor agonist drug, varenicline (Chantix®); the latter being generally recognized to be the most effective. However, each of these approaches afford only limited efficacy, and various other pharmacological approaches are being explored. This chapter focusses on approaches targeted to the serotonin (5-HT) system, namely, selective serotonin reuptake inhibitors (SSRI's) which served a pioneer role in the investigation of serotoninergic modulators in human smoking cessation trials; and secondly drugs selectively interacting with the 5-HT2A and 5-HT2C receptor systems. From an efficacy perspective, measured as smoking abstinence, the 5-HT2A agonist psychedelics, namely psilocybin, seem to show the most promise; although as the article highlights, these findings are both preliminary and there are significant challenges to the route to approval, and therapeutic use of this class should they reach approval status. Additional avenues include 5-HT2C receptor agonists, which until recently was pioneered by lorcaserin, and 5-HT2A receptor antagonists represented by pimavanserin. Each of these approaches has distinct profiles across preclinical tests of nicotine dependence, and may have therapeutic potential. It is anticipated as diagnostic and predictive biomarkers emerge, they may provide opportunities for subject stratification and opportunities for personalizing smoking cessation treatment. The clinical assessment of SSRI, 5-HT2A and/or 5-HT2C receptor-based treatments may be best served by this process.

Vaping and lung cancer - A review of current data and recommendations

OBJECTIVES

Lung cancer is the most common cause of cancer mortality worldwide and, while tobacco smoke remains the primary cause, there is increasing concern that vaping and E-cigarette use may also increase lung cancer risk. This review concentrates on the current data, scholarship and active foci of research regarding potential cancer risk and oncogenic mechanisms of vaping and lung cancer.

MATERIALS AND METHODS

We performed a literature review of current and historical publications on lung cancer oncogenesis, vaping device/e-liquid contents and daughter products, molecular oncogenic mechanisms and the fundamental, potentially oncogenic, effects of electronic cigarette smoke/e-liquid products.

RESULTS

E-cigarette devices and vaping fluids demonstrably contain a series of both definite and probable oncogens including nicotine derivatives (e.g. nitrosnornicotine, nitrosamine ketone), polycyclic aromatic hydrocarbons, heavy metals (including organometal compounds) and aldehydes/other complex organic compounds. These arise both as constituents of the e-liquid (with many aldehydes and other complex organics used as flavourings) and as a result of pyrolysis/complex organic reactions in the electronic cigarette device (including unequivocal carcinogens such as formaldehyde - formed from pyrolysis of glycerol). Various studies demonstrate in vitro transforming and cytotoxic activity of these derivatives. E-cigarette device use has been significantly increasing - particularly amongst the younger cohort and non-smokers; thus, this is an area of significant concern for the future.

CONCLUSION

Although research remains somewhat equivocal, there is clear reason for concern regarding the potential oncogenicity of E-Cigarettes/E-Liquids with a strong basic and molecular science basis. Given lag times (extrapolating from tobacco smoke data) of perhaps 20 years, this may have significant future public health implications. Thus, the authors feel further study in this field is strongly warranted and consideration should be made for tighter control and regulation of these products.

Early Life Exposure to Nicotine: Postnatal Metabolic, Neurobehavioral and Respiratory Outcomes and the Development of Childhood Cancers

Cigarette smoking during pregnancy is associated with numerous obstetrical, fetal, and developmental complications, as well as an increased risk of adverse health consequences in the adult offspring. Nicotine replacement therapy and electronic nicotine delivery systems (e-cigarettes) have been developed as a pharmacotherapy for smoking cessation and are considered safer alternatives for women to smoke during pregnancy. The safety of nicotine replacement therapy use during pregnancy has been evaluated in a limited number of short-term human trials, but there is currently no information on the long-term effects of developmental nicotine exposure in humans. However, animal studies suggest that nicotine alone may be a key chemical responsible for many of the long-term effects associated with maternal cigarette smoking on the offspring and increases the risk of adverse neurobehavioral outcomes, dysmetabolism, respiratory illness, and cancer. This review will examine the long-term effects of fetal and neonatal nicotine exposure on postnatal health.

The mortality of lung cancer attributable to smoking among adults in China and the United States during 1990-2017

Background

Statistical data on the burden and relevant risk factors of lung cancer are valuable for policy‐making. This study aimed to compare the mortality of lung cancer attributable to smoking stratified by sex and age among adults in China and the United States (US).

Methods

We extracted age‐standardized mortality rates of lung cancer during 1990‐2017 using the comparative risk assessment framework of the 2017 Global Burden of Disease study. We performed an age‐period‐cohort analysis to estimate time trend of lung cancer mortality attributable to smoking.

Results

During 1990‐2017, the age‐standardized mortality rate of lung cancer was increasing in China but decreasing in the US for both sexes. The mortality attributable to smoking in China showed a generally increasing trend, while a continuous decrease was observed in the US. The age‐period‐cohort analysis showed a similar trend of age effect among adults between China and the US: the mortality substantially increased from the 30‐34 to 80‐84 age group and subsequently decreased in the 90‐94 age group. However, the period effect rapidly increased in Chinese adults during 1990‐2017, while it tended to be stable in the US although it was still slightly increasing in women. The cohort effect generally peaked in the earlier cohort born in 1902‐1906 in the two countries.

Conclusions

During 1990‐2017, the lung cancer mortality attributable to smoking and the period effect are generally increasing in Chinese adults; the mortality attributable to smoking is decreasing in the US adults, but the period effect tends to be stable. The rapid aging and prevalence of smoking may intensify the increasing mortality of lung cancer in China.

E-cigarettes and Smoking Cessation in the United States According to Frequency of E-cigarette Use and Quitting Duration: Analysis of the 2016 and 2017 National Health Interview Surveys

INTRODUCTION

The purpose of this study was to examine the association between electronic cigarette (e-cigarette) use and smoking cessation among US adults. Duration of smoking cessation was taken into consideration because e-cigarette awareness and use were low in the United States before 2010.

METHODS

A pooled analysis of the 2016 and 2017 National Health Interview Surveys on current (N = 9935) and former smokers (N = 14 754) was performed. Adjusted prevalence ratios (aPRs), for sociodemographic factors, were calculated.

FINDINGS

Current e-cigarette use was reported by 10.5% (95% CI = 9.8% to 11.3%) of current smokers and 4.5% (95% CI = 4.0% to 5.0%) of former smokers. Prevalence was high in former smokers of less than 1 year (16.8%, 95% CI = 13.9% to 20.2%), 1-3 years (15.0%, 95% CI = 13.0% to 17.3%), and 4-6 years (10.5%, 95% CI = 8.6% to 12.7%), and very low in former smokers of more than 6 years (0.7%, 95% CI = 0.5% to 0.9%). Similar patterns were observed for daily e-cigarette use. Current e-cigarette use was negatively associated with being a former smoker when quit duration was ignored (aPR = 0.64, 95% CI = 0.59 to 0.69) but was positively associated with being a former smoker of less than 1 year (aPR = 1.44, 95% CI = 1.12 to 1.84) and 1-3 years (aPR = 1.21, 95% CI = 1.03 to 1.42). Daily e-cigarette use was not associated with being a former smoker when quit duration was ignored but was positively associated with being a former smoker of less than 1 year (aPR = 3.44, 95% CI = 2.63 to 4.49), 1-3 years (aPR = 2.51, 95% CI = 2.13 to 2.95), and 4-6 years (aPR = 1.84, 95% CI = 1.49 to 2.26).

CONCLUSIONS

Daily e-cigarette use is strongly associated with recent smoking cessation (≤6 years) among US adults. Frequency of e-cigarette use and smoking cessation duration are important parameters when analyzing the effects of e-cigarettes in population surveys.

IMPLICATIONS

There is controversy on whether e-cigarettes promote or prevent smoking cessation. This study presents a detailed analysis of the association between e-cigarette use and smoking cessation in the United States considering frequency of e-cigarette use and duration of smoking cessation. The latter was considered appropriate because e-cigarette awareness and use were low in the United States before 2010. Daily e-cigarette use is strongly associated with recent (≤6 years) smoking cessation in the United States. Both frequency of e-cigarette use and duration of smoking cessation are important factors in determining the effects of e-cigarettes in population studies.

Addictions Causing Head-and-Neck Cancers

Head-and-neck cancers pose a serious economic burden, with most countries investing significant resources to reduce the incidence, primarily focusing on understanding addictive etiologies. The traditional literature focused on tobacco and alcohol use, with few studies on contemporary factors such as e-cigarette, waterpipe smoking, and human papillomavirus. This article attempts to collate and present an update on the globally identified etiologic factors.

The aim of this study was to identify and review the addictive etiologic factors causing head-and-neck cancers.

An electronic search was performed on Medline, Embase, and Google Scholar to identify the etiologies causing head-and-neck cancers and narrowed down on those driven by addiction. Further, we identified their constituents, mechanism of action, and the risks attributable to various forms of products.

Substances identified included smoked and chewed tobacco, alcohol, mate, marijuana, areca nut and betel quid, and viruses. An alarming majority of youth are now utilizing these substances. Furthermore, migrant movements have led to the spread of traditional practices across the regions, especially from the Asian subcontinent.

Ironically, despite modern advances and technology, we still see that a large proportion of population succumb to these cancers, emphasizing the need for more effective and targeted policies to combat this menace at the grassroots level.

Consequences of the vaping epidemic on adolescents

The prevalence of vaping has seen a dramatic increase in the last decade, especially among adolescent populations. This article discusses the background, prevalence, and associated risk factors of e-cigarettes.

The Impact of "Vaping" Electronic Cigarettes on Spine Health

“Vaping” or the use of electronic cigarettes (e-cigarettes) has greatly increased within the past decade, with growing popularity among adolescents. E-cigarettes have many harmful effects on multiple organ systems, but more research is needed to fully understand the extent of possible risks. Our narrative literature review aims to provide comprehensive insight into the impact of e-cigarette use on spinal health with a specific focus on intervertebral disc (IVD) health, bone health, and spinal fusion. There are many metallic compounds and chemical flavoring additives within e-cigarette liquids that are associated with human toxicity. These chemical toxins have been linked to increased oxidative stress leading to systemic inflammation. E-cigarette carcinogens have shown to have a toxic effect on osteoblast cells, and long-term use may decrease bone mineral density and increase the future risk for osteoporosis. Additionally, nicotine in e-liquids negatively impacts IVD health by creating hypoxic environments that degenerate the IVD vasculature and cellular matrix. While studies have demonstrated the inhibitory effects of nicotine use on spinal fusions in animal models, the impact of e-cigarette use on spinal fusion operations in human patients is currently lacking. Future research should focus on the influence of e-cigarette use on spinal health, particularly in adolescents with long-term follow-up, as childhood is a critical time for bone growth and development. Additionally, studies exploring the effects of e-cigarettes on spinal surgery outcomes, such as spinal fusions, are sparse in the literature. Further prospective research studies with a focus on the variety of e-cigarette chemical toxins and flavoring agents is needed to assess the impact on spinal health.

Socioeconomic differences in the motivation to stop using e-cigarettes and attempts to do so

Introduction

In England, the use of electronic cigarettes as a smoking cessation aid has become more popular than any other aid. Previous research suggests that ex-smokers from lower social groups are more likely to use e-cigarettes compared to ex-smokers from more socially advantaged groups. The present study aimed to assess the association between baseline education, income and employment status and (1) baseline motivation to stop using e-cigarettes (2) attempts to stop using e-cigarettes during follow-up among current smokers, recent ex-smokers and long-term ex-smokers who use e-cigarettes.

Methods

UK online longitudinal survey of smokers, ex-smokers and e-cigarette users, May/June 2016 (baseline) and September 2017 (follow-up). In logistic regression models, motivation to stop using e-cigarettes at baseline (n = 994) and attempts to stop using e-cigarettes at follow-up (n = 416) among current smokers and ex-smokers were regressed onto baseline educational attainment, income, employment status while adjusting for baseline demographics, vaping status, smoking and e-cigarette dependence.

Results

(1) Respondents with higher education (OR = 1.36; 95% CI: 1.06-1.74) or higher income (OR = 1.52; 95% CI: 1.17-1.98) were more likely to be motivated to stop using e-cigarettes, but only in unadjusted analysis. (2) Again, in unadjusted analysis only, employment was associated with reduced odds of attempting to stop using e-cigarette (OR = 0.50; 95% CI: 0.32-0.79).

Conclusion

Higher socio-economic status may be associated with higher motivation to stop vaping but with lower likelihood of trying to do so.

Welsh Primary Schoolchildren's Perceptions of Electronic Cigarettes: A Mixed Methods Study

There are concerns that the growing popularity of e-cigarettes promotes experimentation among children. Given the influence of the early years on attitude and habit formation, better understanding of how younger children perceive vaping before experimentation begins is needed, to prevent uptake and inform tobacco control strategies. We explored Welsh primary schoolchildren’s (aged 7–11) awareness of e-cigarettes relative to tobacco smoking, their understanding of the perceived risks and benefits and their intentions and beliefs about vaping. Data was collected using a mix of methods in June and July 2017 from 8 purposively selected primary schools across Wales. Four hundred and ninety-five children (52% female) aged 7 years (n = 165), 9 years (n = 185) and 11 years (n = 145) completed a class-administered booklet encompassing a draw and write exercise and survey. Ninety-six children participated in 24 peer discussion groups comprised of 2 boys and 2 girls from each year group. Data were analysed independently and findings triangulated. Survey analyses used frequencies, descriptive statistics and chi-squared tests. Content analysis was undertaken on the draw and write data and peer discussion groups were analysed thematically. Study findings highlight that primary schoolchildren have general awareness of e-cigarettes. Vaping was perceived to be healthier than smoking and there was some recognition that e-cigarettes were used for smoking cessation. Understanding of any health harms was limited. Few children intended to smoke or vape in the future but almost half thought it was okay for grownups. Children’s perceptions were influenced by exposure through family and friends. Findings suggest a need for e-cigarette education in primary schools, to highlight the associated risks of e-cigarette experimentation including the potential for tobacco initiation.

Effects of Different Graphic Health Warning Types on the Intention to Quit Smoking

Anti-smoking advertisements are widely used to demonstrate to smokers the harm of smoking, and graphic health warnings (GHWs) are expected to have a positive effect on the intention to quit smoking. This study investigated which type of GHW (health-related threat (H-GHW) vs. social threat (S-GHW)) is more effective. Two types of GHWs for tobacco were shown to 28 daily smokers and 25 non-smokers while measuring their eye movements using an eye tracker. The time spent fixating on the GHWs was measured as an index of attentional bias. Participants were also asked to evaluate the unpleasantness of the images. They stated their intention to quit smoking in response to each image in a separate session. Multiple regression analysis was used to identify the effects of psychosocial factors on the intention to quit smoking in smokers and the intention to remain as non-smokers in the non-smokers. Both smokers and non-smokers reported greater unpleasantness and cessation intentions in response to H-GHWs than to S-GHWs. Non-smokers found both types of GHWs more unpleasant than smokers did. No differences were found in gaze fixation on GHWs between the two groups. When smokers viewed S-GHWs, the intention to quit smoking was greater as they felt more unpleasant. For non-smokers, the intention to remain non-smokers was greater when they felt more unpleasant and when the attention to H-GHWs was lower. Different psychological factors in anti-smoking advertisements are involved in the intention to quit smoking in smokers and to maintain a non-smoking status in non-smokers. Different approaches should be used according to the types of warning (e.g., warnings emphasizing a negative influence on others or on their own health) in anti-smoking campaigns.

Vaping epidemic: challenges and opportunities

This article is a timely, concise, and unbiased analysis of the national and international responses to the spate of vaping-related lung illnesses and deaths and the epidemic of teen vaping. In view of the recent outbreak of vaping-related lung injuries and deaths in the USA and the epidemic of teen vaping, the viewpoints and recommendations presented in this article have immediate policy implications in the USA and around the world. The perspectives and recommendations are expected to assist medical communities, public health professionals, and regulatory authorities in addressing complex issues related to vaping regulation, which are intertwined with public health, economy, and politics of nations, worldwide.

Patterns of tobacco and e-cigarette use status in India: a cross-sectional survey of 3000 vapers in eight Indian cities

Background

Tobacco smoking is one of the biggest and avoidable public health threats in the world, especially in low- and middle-income countries. India represents a highly complex public health environment due to the large number of smokers and complexities arising from tobacco use in different forms, including a variety of smokeless tobacco (SLT) products. Electronic cigarettes, an alternative nicotine delivery system with significantly less harmful emissions than smoke, could be an option for those who are unable to achieve smoking abstinence using other available means. This study, which we believe is the first of this kind in India, was conducted to obtain data on the characteristics and tobacco use profile of e-cigarette users (vapers) in India.

Methods

An interview-based survey was performed in the 8 largest metropolitan cities in India using a convenience sampling approach involving a total of 3000 subjects. Inclusion criteria were being a current e-cigarette user and aged 18 years or more. Interviewers were asked to continue recruitment until a total sample of 375 was reached in each target city.

Results

A total of 3000 vapers (81.4% males and 18.6% females, median age 29 years) participated to the study. The majority (80%) were first exposed to nicotine via tobacco smoking, SLT use, or both. Most of the subjects (79%) believed that e-cigarettes were less harmful than smoking. The vast majority of smokers (71.3%) reported smoking cessation (30.0%) or reduction in consumption (41.3%) with the help of e-cigarettes. Similar changes were observed in SLT users. Participants reported minimal side effects and some health benefits after e-cigarette use initiation.

Conclusion

Indian vapers who participated to this study were predominantly smokers and SLT users before e-cigarette use initiation, with the majority subsequently quitting or reducing tobacco use. Minimal side effects of e-cigarette were experienced, while some health benefits were also reported.

Hypomethylation of LINE-1 repeat elements and global loss of DNA hydroxymethylation in vapers and smokers

The outbreak of vaping-related severe lung injuries and deaths and the epidemic of teen vaping in the U.S. underscore the urgent need for determining the biological consequences of electronic cigarette (e-cig) use. We have investigated the association between vaping and epigenetic changes by quantifying DNA methylation levels in Long Interspersed Nucleotide Element 1 (LINE-1) and global DNA hydroxymethylation (5-hmC) levels and measuring the expression level of enzymes catalysing the respective processes in peripheral blood of exclusive vapers, smokers, and controls, matched for age, gender, and race (n = 45). Both vapers and smokers showed significant loss of methylation in LINE-1 repeat elements in comparison to controls (P = 0.00854 and P = 0.03078, respectively). Similarly, vapers and smokers had significant reductions in 5-hmC levels relative to controls (P = 0.04884 and P = 0.0035, respectively). Neither the LINE-1 methylation levels nor the global 5-hmC levels were different between vapers and smokers. There was a direct correlation between methylation levels in the LINE-1 elements and global 5-hmC levels in the study subjects (r = 0.31696, P = 0.03389). Inverse and statistically significant correlations were found between both the LINE-1 methylation levels and the global 5-hmC levels and various vaping/smoking metrics in the study subjects. There were modest but not statistically significant changes in transcription of DNA methyltransferases and ten-eleven translocation enzymes in both vapers and smokers relative to controls. Our findings support follow-up genome-wide investigations into the epigenetic effects of vaping, which may further clarify the health consequences of e-cig use.

ABBREVIATIONS

5-mC: 5-methylcytosine; 5-hmC: 5-hydroxymethylcytosine; 8-OHdG: 8-hydroxy-2'-deoxyguanosine; ACTIN: actin beta; ANOVA: Analysis of Variance; BER: base excision repair; BMI: body mass index; CO: carbon monoxide; COHb: carboxyhaemoglobin; COBRA: combined bisulphite restriction analysis; COPD: chronic obstructive pulmonary disease; DNMT1: DNA methyltransferase 1; DNMT3A: DNA methyltransferase 3A; DNMT3B: DNA methyltransferase 3B; e-cigs: electronic cigarettes; ELISA: enzyme-linked immunosorbent assay; ENDS: electronic nicotine delivery systems; FDA: Food and Drug Administration; GAPDH; glyceraldehyde-3-phosphate dehydrogenase; HPLC: high-performance liquid chromatography; LINE-1: Long Interspersed Nucleotide Element 1; PBS: phosphate-buffered saline; RFU: relative fluorescence units; RT-qPCR: quantitative reverse-transcription polymerase chain reaction; ROS: reactive oxygen species; SAM, S-adenosylmethionine; SE: standard error; TET1: ten-eleven translocation 1; TET2: ten-eleven translocation 2; TET3: ten-eleven translocation 3.

A qualitative study of e-cigarette emergence and the potential for renormalisation of smoking in UK youth

BACKGROUND

Growth of e-cigarette use among smokers has raised concerns over uptake by non-smokers, particularly young people. Legislative changes aimed in part at reducing youth exposure to e-cigarettes include the EU Tobacco Products Directive (TPD). A core justification for such measures is the belief that e-cigarettes can lead to tobacco smoking through mechanisms of renormalisation including: mimicking and normalizing the act of smoking; increasing product acceptability via marketing; nicotine exposure. These mechanisms are here explored in relation to findings from qualitative research.

METHODS

This paper reports results from twenty-one group interviews with 14-15 year olds in Wales, England and Scotland, conducted as part of an ongoing evaluation of the impact of the TPD on youth smoking and e-cigarette use. Interviews were conducted around the end of the transitional period for TPD implementation, and explored perceptions of e-cigarettes and tobacco, as well as similarities and differences between them.

RESULTS

Young people differentiated between tobacco and e-cigarettes, rejecting the term e-cigarette in favour of alternatives such as 'vapes'. Experimental or occasional use was common and generally approved of where occurring within social activity with peers. However, regular use outside of this context was widely disapproved of, unless for the purpose of stopping smoking. Increased prevalence of e-cigarettes did not challenge strongly negative views of smoking or reduce perceived harms caused by it, with disapproval of smoking remaining high. Nicotine use was variable, with flavour a stronger driver for choice of e-liquid, and interest more generally.

CONCLUSION

The extent to which participants differentiated between vaping and smoking, including styles and reasons for use in adults and young people; absence of marketing awareness; and continued strong disapproval of smoking provides limited support for some of the potential mechanisms through which e-cigarettes may renormalise smoking. However caution over nicotine exposure is still necessary.

Electronic cigarettes: where to from here?

Although the usage of electronic (e)-cigarettes (EC) and similar devices has gained in popularity as an apparent smoking cessation strategy, serious concerns are emerging in relation to both the efficacy of this strategy, as well as the inappropriate use of these devices. While the comparative safety of e-cigarettes is based on the reasonable contention that the levels of inhaled toxicants present in the aerosols generated by these devices are considerably lower than those present in tobacco smoke, the perception that they are indeed relatively risk-free is being challenged on several fronts. Notwithstanding lack of convincing evidence of efficacy as a superior smoking cessation strategy, foremost among emerging concerns is the increasing use of electronic nicotine-delivery devices by young never-smokers. Other concerns include increasing levels of sophistication in the design and capacity of these devices in relation to nicotine content and delivery, the potential threat of manipulation of the contents of e-liquids, as well as other additives such as illicit drugs and other potentially toxic agents that can be vaporised. These issues, together with the potential risks to respiratory health, specifically "e-cigarette or vaping product use-associated lung injury" represent the major thrusts of this review.

Substance Use in Adolescents: Latest Trends

Adolescent substance use is an ever-changing topic that can be difficult to stay on top of its many components. Recent data show encouraging declines in the use of some substances such as cigarettes, alcohol, and opioids, although they are still prevalent in the adolescent population. Newer issues such as vaping and the legalization of marijuana bring up new challenges in discussing substance use with young patients. Perceptions of risk and evolving campaigns aimed at young people make these two topics particularly important to address with adolescents. This article reviews the statistics regarding the most commonly used substances in the United States, and some important ways that we can reach out to the adolescent population that is so vulnerable to the harms of substance use. [Pediatr Ann. 2019;48(11):e418-e422.].

Inclusion of electronic nicotine delivery systems in indoor smoke-free air policies and associated vaping behavior

INTRODUCTION

Despite an ongoing debate over regulations of use of electronic nicotine delivery systems (ENDS) in public places, fourteen U.S. states or territories banned use of ENDS in indoor areas such as workplaces, restaurants, or bars (aerosol-free policies), as of March 31 ,2018. However, there is a paucity of studies on state-level aerosol-free policies. This study aimed to investigate the relationship between statewide aerosol-free policies and U.S. adults' ENDS use.

METHODS

We analyzed data from the 2016 Behavioral Risk Factor Surveillance System, a nationally representative sample of U.S. adults (N = 240,849, ages 18-59 years), using multilevel logistic regressions, taking into account clustering of individuals within a state. We conducted stratified analyses by age groups to examine if the association between aerosol-free policy and ENDS use would be different between different age groups of adults.

RESULTS

Adults living in the states with an aerosol-free policy were less likely to use ENDS compared with those living in the states without an aerosol-free policy, controlling for individual- and state-level covariates (adjusted odds ratio = 0.79, 95% confidence interval = 0.64, 0.97). Stratified analyses showed that the association varied by age group; the statewide aerosol-free policies was associated with lower odds of ENDS use only in adults aged 25-59 but not young adults (aged 18-24).

CONCLUSIONS

The results supported enforcement of prohibiting ENDS as well as traditional tobacco product indoor areas as a means of ENDS use prevention. Our findings also confirmed that young adults should be a priority target population for ENDS use prevention policies and programming efforts.

Technology-based contingency management and e-cigarettes during the initial weeks of a smoking quit attempt

Contingency management (CM) interventions are among the most effective behavioral interventions for smoking. This study assessed the effects of CM and electronic cigarettes (ECs) on smoking reductions and abstinence for durations of 30-36 days. Twelve participants were exposed to Baseline, EC alone, and EC + CM conditions. An internet-based platform was used to monitor smoking via breath carbon monoxide (CO) and deliver CM for smoking abstinence (CO ≤4 ppm). A Bluetooth-enabled EC monitored daily EC puffs. Abstinence rates were equivalent between EC (34.4%) and EC + CM (30.4%) conditions. Both conditions promoted smoking reductions. We observed an inverse correlation between smoking and EC puffs (r = -.62, p < .05). Results suggest the use of electronic cigarettes can promote smoking reductions and abstinence, and CM did not improve these outcomes. Larger magnitude consequences or tailoring EC characteristics (e.g., flavor) may have improved outcomes. Technology-based methods to collect intensive, longitudinal measures of smoking and electronic cigarette use may be useful to characterize their environmental determinants.

Patterns of e-cigarette use, biochemically verified smoking status and self-reported changes in health status of a random sample of vapeshops customers in Greece

To understand the population impact of e-cigarettes, it is important to examine the profile of e-cigarette users. The purpose was to examine the characteristics, patterns of e-cigarette use and smoking status of a random sample of vapeshops customers in Greece. Fourteen vapeshops were randomly selected in the region of Athens. Every third customer buying products for personal use was recruited by a researcher visiting the vapeshops. Current smoking status was assessed by measuring exhaled carbon monoxide (eCO), with a value ≥ 7 ppm being used to classify subjects as current smokers. A questionnaire was used to examine past smoking status, patterns of e-cigarette use, changes in health status and experienced side effects. Logistic regression analysis was performed to identify correlates of being a former smoker. A total of 309 participants were analyzed, with 82.5% being daily e-cigarette users. The vast majority (98%) were smokers before e-cigarette use initiation, with 69.6% of them having eCO < 7 ppm (former smokers). Only 1% were never smokers, and 1% had quit smoking before e-cigarette use initiation; all of them had eCO < 7 ppm. Most participants were using third-generation devices (61.8%) and were using non-tobacco flavors (58.9%). The average liquid consumption was 5 mL/day. Most participants experienced health benefits, mainly improvement in physical status, exercise capacity, olfactory and gustatory senses, while the most common side effects were throat irritation and cough. The strongest correlate of being a former smoker was daily e-cigarette use. Vapeshops customers in Greece are mainly current and former smokers with the majority of them having quit smoking. E-cigarette use by never smokers is rare and none of them subsequently initiate smoking.

A randomised, open-label, cross-over clinical study to evaluate the pharmacokinetic profiles of cigarettes and e-cigarettes with nicotine salt formulations in US adult smokers

E-cigarettes containing 'nicotine salts' aim to increase smoker's satisfaction by improving blood nicotine delivery and other sensory properties. Here, we evaluated the pharmacokinetic profiles and subjective effects of nicotine from two e-cigarette device platforms with varying concentrations of nicotine lactate (nicotine salt) e-liquid relative to conventional cigarettes. A randomised, open-label, cross-over clinical study was conducted in 15 healthy US adult smokers. Five different e-cigarette products were evaluated consecutively on different days after use of own brand conventional cigarette. Plasma nicotine pharmacokinetics, subjective effects, and tolerability were assessed following controlled use of the products. The rate of nicotine absorption into the bloodstream was comparable from all e-cigarettes tested and was as rapid as that for conventional cigarette. However, in all cases, nicotine delivery did not exceed that of the conventional cigarette. The pharmacokinetic profiles of nicotine salt emissions were also dependent upon the properties of the e-cigarette device. Subjective scores were numerically highest after smoking a conventional cigarette followed by the myblu 40-mg nicotine salt formulation. The rise in nicotine blood levels following use of all the tested e-cigarettes was quantified as 'a little' to 'modestly' satisfying at relieving the desire to smoke. All products were well tolerated with no notable adverse events reported. These results demonstrate that, while delivering less nicotine than a conventional cigarette, the use of nicotine salts in e-cigarettes enables cigarette-like pulmonary delivery of nicotine that reduces desire to smoke.

E-cigarette use is strongly associated with recent smoking cessation: an analysis of a representative population sample in Greece

The purpose was to examine the association between e-cigarette use and smoking cessation according to quit duration in Greece in 2017. A cross-sectional survey of a representative sample of adults living in Attica prefecture was performed in May 2017 through telephone interviews. The present analysis was confined to current and former smokers (n = 2568). Logistic regression analyses were performed with current and current daily e-cigarette use being the dependent variables and demographics and smoking status (current smokers vs smoking cessation for ≤ 12 months, 13-36 months, 36-72 months, and > 72 months) being independent variables. Almost half of former smokers (47.7%) had quit smoking for ≤ 72 months. Current e-cigarette use was more prevalent among former smokers of ≤ 12 months (26.2%) and 13-36 months (27.0%), and was rare among former smokers of > 72 months (1.0%). Current e-cigarette use was strongly associated with smoking cessation for ≤ 12 months (OR 6.12, 95% CI 4.11-9.10, P < 0.001) and 13-36 months (OR 6.28, 95% CI 4.25-9.28, P < 0.001). Current daily e-cigarette use was also strongly associated with smoking cessation for ≤ 12 months (OR 10.41, 95% CI 6.56-16.53, P < 0.001) and 13-36 months (OR 11.18, 95% CI 7.12-17.55, P < 0.001). Current and current daily e-cigarette use were not significantly associated with smoking cessation for 37-72 months, and were negatively associated with smoking cessation for > 72 months. Current and current daily e-cigarette use are strongly associated with recent smoking cessation in Greece, suggesting a positive public health impact in a country with the highest prevalence of smoking in the European Union. E-cigarettes do not appear to promote relapse in long term former smokers. Duration of smoking cessation and frequency of e-cigarette use should be taken into consideration when examining the association between e-cigarette use and smoking cessation in population studies.