E-Cigarettes and Cardiopulmonary Health

E-cigarette use, perceived risks, attitudes, opinions of e-cigarette policies, and associated factors among Thai university students

INTRODUCTION

Although many countries, including Thailand, currently ban the sale of e-cigarettes, their use continues to rise, especially among young adults. Since the study of e-cigarette use among university students is limited, this study aimed to determine factors associated with e-cigarette use and explore university students' attitudes toward e-cigarettes, perceived risk, and opinion of e-cigarette policies.

METHODS

This cross-sectional study was conducted among undergraduate students using convenience sampling in a university, in central Thailand from November 2022 to February 2023. A self-administered online questionnaire was distributed to 19 faculties representing health sciences, science and technology, social and arts faculties, and the International College.

RESULTS

A total of 548 students completed the online questionnaire, and 20.4% reported ever using e-cigarettes, while 40% of e-cigarette users were unsure about the nicotine content. About 28% agreed, and 22% were unsure whether e-cigarettes could help quit smoking. Most students perceived that e-cigarettes are addictive and harmful, while about half of the participants agreed with the policy related to e-cigarettes in Thailand. Students with positive attitudes towards e-cigarettes were more likely to use e-cigarettes (AOR=1.15; 95% CI: 1.08-1.22), and those with lower perceived risk (AOR=0.89; 95% CI: 0.82-0.96) and who disagreed with e-cigarettes policy (AOR=0.93; 95% CI: 0.89-0.97) were more likely to use e-cigarettes. Personal income and having friends who use e-cigarettes were the significant predictors for e-cigarette use, while studying in the faculty of science and technology was a predictor of using e-cigarettes last month.

CONCLUSIONS

Although the perceived risk was high, about half of the students thought that e-cigarettes could help them quit smoking and were unsure or disagreed with e-cigarette banning policies. Attitude, perceived risk, policy opinions, personal income, and having friends who used e-cigarettes, were associated with e-cigarette use. Thus, correcting misunderstandings and increasing risk perceptions about e-cigarettes must be advocated among university students.

Association of cigarette and electronic cigarette use patterns with all-cause mortality: A national cohort study of 145,390 US adults

OBJECTIVE

While e-cigarette use is associated with adverse cardiopulmonary health effects, the mortality risks associated with e-cigarette use alone and combined with smoking remain unexamined.

METHODS

Data between 2014 and 2018 were obtained from the National Health Interview Survey (NHIS), an annual cross-sectional survey of US adults. All-cause mortality and date of death were obtained via linkage of the NHIS to the National Death Index through December 31, 2019. A 6-category composite cigarette (never, former, current) and e-cigarette (current, non-current) exposure variable was created. We examined the association of cigarette and e-cigarette use patterns with all-cause mortality using adjusted Cox models.

RESULTS

Among 145,390 participants (79,294 women [51.5%]; 60,560 aged 18-44 [47.4%]), 5220 deaths were observed over a median follow-up of 3.5 years (508,545 total person-years). Dual use of cigarettes and e-cigarettes was associated with higher mortality risk compared with non-current e-cigarette use in combination with never smoking (hazard ratio [HR] 2.44; 95% CI, 1.90-3.13) and had a risk that did not differ from current exclusive smoking (HR, 1.06; 95% CI, 0.83-1.37). Current e-cigarette use in combination with former smoking was associated with a lower mortality risk than current exclusive cigarette smoking (HR 0.64; 95% CI, 0.41-0.99).

CONCLUSIONS

The addition of e-cigarette use to smoking does not reduce mortality risk compared with exclusive smoking. However, transitioning completely from cigarettes to e-cigarettes may be associated with mortality risk reduction. Further research is needed to verify these findings in larger cohorts and over longer periods of follow-up.

Vuse Solo e-cigarettes do not provide net benefits to public health: a scientific analysis of FDA's marketing authorisation

In October 2021, the US Food and Drug Administration (FDA) authorised marketing of RJ Reynolds Vapor Company's (RJR) Vuse Solo e-cigarette through FDA's Premarket Tobacco Product Application (PMTA) pathway. FDA concluded that RJR demonstrated Vuse products met the statutory standard of providing a net benefit to public health. A review of FDA's scientific justification reveals deficiencies: (1) not adequately considering Vuse's popularity with youth and evidence that e-cigarettes expanded the nicotine market and stimulate cigarette smoking; (2) trading youth addiction for unproven adult benefit without quantifying these risks and benefits; (3) not considering design factors that appeal to youth; (4) not addressing evidence that e-cigarettes used as consumer products do not help smokers quit and promote relapse in former smokers; (5) not discussing evidence that dual use is more dangerous than smoking; (6) narrowly focusing on the fact that e-cigarettes deliver lower levels of some toxicants without addressing direct evidence on adverse health effects; (7) downplaying significant evidence of other substantial harms; (8) not acting on FDA's own study showing no all-cause mortality benefit of reducing (but not stopping) cigarette use; and (9) improperly considering e-cigarettes' high abuse liability and potential for high youth addiction and undermining tobacco cessation. Because marketing these products is not appropriate for the protection of the public health, FDA should reconsider its Vuse marketing order as statutorily required and not use it as a template for other e-cigarette PMTAs. Policymakers outside the USA should anticipate that tobacco companies will use FDA's decision to try to weaken tobacco control regulation of e-cigarettes and promote their products.

Long-term effects of chronic exposure to electronic cigarette aerosol on the cardiovascular and pulmonary system in mice: A comparative study to cigarette smoke

Electronic cigarettes (e-cigarettes) have rapidly gained popularity as alternatives to traditional combustible cigarettes. However, their long-term health impact remains uncertain. This study aimed to investigate the effects of chronic exposure to e-cigarette aerosol (ECA) in mice compared to conventional cigarette smoke (CS) exposure. The mice were exposed to air (control), low, medium, or high doses of ECA, or a reference CS dose orally and nasally for eight months. Various cardiovascular and pulmonary assessments have been conducted to determine the biological and prosthetic effects. Histopathological analysis was used to determine structural changes in the heart and lungs. Biological markers associated with fibrosis, inflammation, and oxidative stress were investigated. Cardiac proteomic analysis was applied to reveal the shared and unique protein expression changes in ECA and CS groups, which related to processes such as immune activation, lipid metabolism, and intracellular transport. Overall, chronic exposure to ECA led to adverse cardiovascular and pulmonary effects in mice, although they were less pronounced than those of CS exposure. This study provides evidence that e-cigarettes may be less harmful than combustible cigarettes for the long-term health of the cardiovascular and respiratory systems in mice. However, further human studies are needed to clarify the long-term health risks associated with e-cigarette use.

Population-Based Disease Odds for E-Cigarettes and Dual Use versus Cigarettes

Disease Odds for E-Cigarettes and Dual Use versus CigarettesE-cigarettes have been promoted as less harmful than cigarettes. In this meta-analysis, Glantz et al. show that for some diseases, e-cigarette disease risks were similar to cigarettes, and for others e-cigarettes were nearly as risky as cigarettes. The risks associated with dual use were higher than those for smoking alone.

Optical characterization of native aerosols from e-cigarettes in localized volumes

Measuring the size distribution of aerosols typically requires processing a sample, specifically to adjust the particle concentration to an adequate level. Unfortunately, this manipulation can significantly alter the native composition of some aerosols, which can lead to unreliable or even unusable measurements. We demonstrate that coherence-gated dynamic light scattering is suitable to measure the size distribution of native aerosols without the need for sample processing. Another novel aspect of the present work is the first demonstration of these type of localized light-scattering-based measurements in aerial media. Measuring the size distribution reliably in optically dense aerosols is possible thanks to the interferometric amplification of single scattering in an optically isolated, picolitre-sized coherence volume. We carried out proof-of-concept experiments in aerosols from electronic cigarettes, which poses a challenge mainly due to their high concentration, volatility, and hygroscopicity. We generated aerosols using two common moisturizers, propylene glycol and glycerol, and measured their particle size distribution as a function of the burning power. The aerosols generated in the presence of glycerol are more polydisperse and have larger particles with increasing burning power. This unique characterization of native aerosols can provide valuable information for dosimetry and hosting sites in the respiratory system.

Effects of Nicotine Content and Preferred Flavor on Subjective Responses to E-cigarettes: A Randomized, Placebo-controlled Laboratory Study

INTRODUCTION

Evidence suggests that e-liquid flavor and nicotine concentration are important factors in the initiation and maintenance of e-cigarette use (vaping). Flavors may increase the initiation and maintenance of vaping, and nicotine content is a factor in e-cigarette dependence and the efficacy of e-cigarettes for cigarette smoking cessation. Few human laboratory studies have assessed the joint and interactive effects of flavor and nicotine on subjective responses to e-cigarettes.

METHODS

Regular e-cigarette users (N = 89) completed a multi-session study involving a paced vaping procedure with e-liquid cartridges containing their preferred flavor (berry, menthol, or tobacco) or no flavor, with or without nicotine (18 mg). Subjective effects of vaping (satisfaction, reward, aversion, airway sensations, and craving relief) were assessed.

RESULTS

Nicotine significantly increased psychological reward and craving relief, whereas flavor significantly increased vaping satisfaction and taste. Nicotine dependence severity moderated the effect of nicotine on reward, such that those with the greatest dependence severity reported the greatest reward.

CONCLUSIONS

These findings support differential and noninteractive effects of e-liquid nicotine content and flavor on reinforcing effects of e-cigarettes.

IMPLICATIONS

E-liquid flavor and nicotine content have independent, non-interactive effects on subjective responses to vaping under controlled laboratory conditions. Among regular e-cigarette users, vaping a preferred flavor increased taste and satisfaction, but did not interact with nicotine to alter reward or craving. Further research on the ways in which these subjective effects may motivate vaping behavior among different populations of e-cigarette users would be useful to inform regulatory policy of ENDS products.

Healthcare utilisation and expenditures attributable to current e-cigarette use among US adults

AIMS

This study estimated annual healthcare expenditures attributable to current e-cigarette use among US adults, including current exclusive and dual/poly e-cigarette use.

METHODS

Analysing the 2015-2018 National Health Interview Survey data, we estimated the impacts of e-cigarette use on healthcare utilisation among adults aged 18+ years. Healthcare utilisation outcomes were hospital nights, emergency room (ER) visits, doctor visits and home visits. Current e-cigarette use was categorised as exclusive and dual/poly e-cigarette use. The econometric model included two equations: health status as a function of e-cigarette use and other independent variables, and healthcare utilisation as a function of health status, e-cigarette use, and other independent variables. Using an 'excess utilisation' approach, we multiplied the e-cigarette-attributable fraction derived from the model by annual health expenditures to calculate healthcare expenditures attributable to current exclusive and dual/poly e-cigarette use, the sum of which were expenditures attributable to all current e-cigarette use.

RESULTS

Current exclusive and dual/poly e-cigarette use, with 0.2% and 3.5% prevalence in 2015-2018, were associated with higher odds of reporting poor health status than never tobacco users. Poor health status was associated with higher odds of using the four healthcare services and a greater number of ER and doctor visits. Annual healthcare expenditures attributable to all current e-cigarette use was $15.1 billion ($2024 per user) in 2018, including $1.3 billion attributable to exclusive e-cigarette use ($1796 per user) and $13.8 billion attributable to dual/poly e-cigarette use ($2050 per user).

CONCLUSION

Adult current e-cigarette use was associated with substantial excess healthcare utilisation and expenditures.

E-cigarettes and arrhythmogenesis: a comprehensive review of pre-clinical studies and their clinical implications

Electronic cigarette use has grown exponentially in recent years, and while their popularity has increased, the long-term effects on the heart are yet to be fully studied and understood. Originally designed as devices to assist with those trying to quit traditional combustible cigarette use, their popularity has attracted use by teens and adolescents who traditionally have not smoked combustible cigarettes. Acute effects on the heart have been shown to be similar to traditional combustible cigarettes, including increased heart rate and blood pressure. The main components of electronic cigarettes that contribute to these arrhythmic effects are found in the e-liquid that is aerosolized and inhaled, comprised of nicotine, flavourings, and a combination of vegetable glycerin (VG) and propylene glycol (PG). Nicotine can potentially induce both ventricular and atrial arrhythmogenesis, with both the atrial and ventricular effects resulting from the interactions of nicotine and the catecholamines they release via potassium channels. Atrial arrhythmogenesis, more specifically atrial fibrillation, can also occur due to structural alterations, which happens because of nicotine downregulating microRNAs 133 and 590, both post-transcriptional growth factor repressors. Liquid flavourings and the combination of PG and VG can possibly lead to arrhythmic events by exposing users to acrolein, an aldehyde that stimulates TRPA1 that in turn causes a change towards sympathetic activation and autonomic imbalance. The design of these electronic delivery devices is constantly changing; therefore, it has proven extremely difficult to study the long-term effects on the heart caused by electronic cigarettes but will be important to understand given their rising popularity. The arrhythmic effects of electronic cigarettes appear similar to traditional cigarettes as well; however, a comprehensive review has not been compiled and is the focus of this article.

Electronic Cigarette Harms: Aggregate Evidence Shows Damage to Biological Systems

Evidence of the harms of e-cigarettes has been unfolding slowly and has been documented in many reviews and reports worldwide. A narrative review of new evidence is presented since, as research has continued, newly aggregated evidence of the dangers of electronic cigarettes on the brain, heart, and lungs is vital to inform decisions on restricting the use of e-cigarettes. Several biomedical research databases were searched for electronic cigarette health effects, emphasizing reviews, systematic reviews, and meta-analyses. Over 50 review studies, primarily in 2022 and 2023, illustrate some of the latest information on e-cigarette harms. Results show studies of respiratory, neurological, and cardiovascular effects. Researchers call for expanding studies through new methods to elaborate on initial findings of multiple harms emerging in clinical investigations. Since the use of electronic cigarettes for adult cessation is not sanctioned in most countries, it is clear that health authorities see significant costs to the health of the general population if the promotion and use of electronic cigarettes occur worldwide. Regulatory action to control electronic cigarettes should consider the substantial evidence of electronic cigarette harm.

Cardiopulmonary Impact of Electronic Cigarettes and Vaping Products: A Scientific Statement From the American Heart Association

Vaping and electronic cigarette (e-cigarette) use have grown exponentially in the past decade, particularly among youth and young adults. Cigarette smoking is a risk factor for both cardiovascular and pulmonary disease. Because of their more limited ingredients and the absence of combustion, e-cigarettes and vaping products are often touted as safer alternative and potential tobacco-cessation products. The outbreak of e-cigarette or vaping product use-associated lung injury in the United States in 2019, which led to >2800 hospitalizations, highlighted the risks of e-cigarettes and vaping products. Currently, all e-cigarettes are regulated as tobacco products and thus do not undergo the premarket animal and human safety studies required of a drug product or medical device. Because youth prevalence of e-cigarette and vaping product use was as high as 27.5% in high school students in 2019 in the United States, it is critical to assess the short-term and long-term health effects of these products, as well as the development of interventional and public health efforts to reduce youth use. The objectives of this scientific statement are (1) to describe and discuss e-cigarettes and vaping products use patterns among youth and adults; (2) to identify harmful and potentially harmful constituents in vaping aerosols; (3) to critically assess the molecular, animal, and clinical evidence on the acute and chronic cardiovascular and pulmonary risks of e-cigarette and vaping products use; (4) to describe the current evidence of e-cigarettes and vaping products as potential tobacco-cessation products; and (5) to summarize current public health and regulatory efforts of e-cigarettes and vaping products. It is timely, therefore, to review the short-term and especially the long-term implications of e-cigarettes and vaping products on cardiopulmonary health. Early molecular and clinical evidence suggests various acute physiological effects from electronic nicotine delivery systems, particularly those containing nicotine. Additional clinical and animal-exposure model research is critically needed as the use of these products continues to grow.

Single cell RNA-sequencing of human precision-cut lung slices: A novel approach to study the effect of vaping and viral infection on lung health

Vaping is an increasing health threat in the US and worldwide. The damaging impact of vaping on the human distal lung has been highlighted by the recent epidemic of electronic cigarette or vaping use-associated lung injury (EVALI). The pathogenesis of EVALI remains incompletely understood, due to a paucity of models that recapitulate the structural and functional complexity of the human distal lung and the still poorly defined culprit exposures to vaping products and respiratory viral infections. Our aim was to establish the feasibility of using single cell RNA-sequencing (scRNA-seq) technology in human precision-cut lung slices (PCLS) as a more physiologically relevant model to better understand how vaping regulates the antiviral and pro-inflammatory response to influenza A virus infection. Normal healthy donor PCLS were treated with vaping extract and influenza A viruses for scRNA-seq analysis. Vaping extract augmented host antiviral and pro-inflammatory responses in structural cells such as lung epithelial cells and fibroblasts, as well as in immune cells such as macrophages and monocytes. Our findings suggest that human distal lung slice model is useful to study the heterogeneous responses of immune and structural cells under EVALI conditions, such as vaping and respiratory viral infection.

Time-varying association between cigarette and ENDS use on incident hypertension among US adults: a prospective longitudinal study

OBJECTIVE

Electronic nicotine delivery systems (ENDS) products have emerged as the most popular alternative to combustible cigarettes. However, ENDS products contain potentially dangerous toxicants and chemical compounds, and little is known about their health effects. The aim of the present study was to examine the prospective association between cigarette and ENDS use on self-reported incident hypertension.

DESIGN

Longitudinal cohort study.

SETTING

Nationally representative sample of the civilian, non-institutionalised population in the USA.

PARTICIPANTS

17 539 adults aged 18 or older who participated at follow-up and had no self-reported heart condition or previous diagnosis of hypertension or high cholesterol at baseline.

MEASURES

We constructed a time-varying tobacco exposure, lagged by one wave, defined as no use, exclusive established use (every day or some days) of ENDS or cigarettes, and dual use. We controlled for demographics (age, sex, race/ethnicity and household income), clinical risk factors (family history of heart attack, obesity, diabetes and binge drinking) and smoking history (cigarette pack-years).

OUTCOMES

Self-reported incident hypertension diagnosis.

RESULTS

The self-reported incidence of hypertension was 3.7% between wave 2 and wave 5. At baseline, 18.0% (n=5570) of respondents exclusively smoked cigarettes; 1.1% (n=336) exclusively used ENDS; and 1.7% (n=570) were dual users. In adjusted models, exclusive cigarette use was associated with an increased risk of self-reported incident hypertension compared with non-use (adjusted HR (aHR) 1.21, 95% CI 1.06 to 1.38), while exclusive ENDS use (aHR 1.00, 95% CI 0.68 to 1.47) and dual use (aHR 1.15, 95% CI 0.87 to 1.52) were not.

CONCLUSIONS

We found that smoking increased the risk of self-reported hypertension, but ENDS use did not. These results highlight the importance of using prospective longitudinal data to examine the health effects of ENDS use.

The association between combustible/electronic cigarette use and stroke based on national health and nutrition examination survey

AIMS

This study aims to analyze the association between combustible/electronic cigarettes and the risk of stroke.

METHODS

We obtained data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES). The stroke history and combustible/electronic cigarette use were acquired by questionnaires. Considering the sole or dual use of combustible cigarettes and electronic cigarettes (e-cigarettes), we divided all the individuals into four subgroups, including nonsmokers (reference group), sole combustible cigarette, sole e-cigarette, and dual use of both combustible cigarettes and e-cigarettes. We performed multivariable logistic regression to determine the association between cigarette use with the prevalence of stroke. We used odds ratios (ORs) with 95% confidence intervals (CIs) to show the effect size. Finally, we developed a prediction model to evaluate the risk of stroke for individuals with combustible or electronic cigarette use based on a random forest model.

RESULTS

We included a total of 4022 participants in the study. The median age was 55, and 48.3% of the participants were males. When we adjusted for age, gender, education attainment, race, total-to-HDL cholesterol (< 5.9 or ≥ 5.9), diabetes, hypertension, and alcohol consumption, the groups of sole e-cigarette use, sole combustible cigarette use, and dual use of combustible and electronic cigarettes were significantly associated with the prevalence of stroke with ORs (with 95%CI) of 2.07 (1.04-3.81), 2.36 (1.52-3.59), 2.34 (1.44-3.68), respectively. In the testing set, the AUC was 0.74 (95%CI = 0.65-0.84), sensitivity was 0.68, and specificity was 0.75.

CONCLUSION

Sole e-cigarettes and dual use of e-cigarettes with combustible cigarettes might increase the risk of stroke.

Classification, Perception, and Toxicity of Emerging Flavored Oral Nicotine Pouches

INTRODUCTION

Oral Nicotine Pouches (ONPs) are the new form of nicotine pouches that have become a type of emerging smokeless tobacco product sold by various tobacco companies. These smokeless tobacco products are marketed for usage all over as snus containing tobacco-derived nicotine (natural) or as tobacco-free nicotine (synthetic) as substitutes for other tobacco products. Based on perception and socio-behavioral aspects, ONPs have become popular tobacco products among adolescents/young adults, and over 50% of young adult users of ONP use flavored ONPs, such as menthol/mint, tobacco, dessert/candy, and fruity, which are the most popular flavors. Various new ONP flavors are currently popular locally as well as in the online market. Tobacco, menthol, and fruit-flavored ONPs could motivate cigarette smokers to change to ONPs.

METHODS

We expanded our knowledge on natural/synthetic ONP flavor wheels to available data on ONPs, describing, in detail, their flavors and brands (US and Europe) in both natural and synthetic ONP categories. We classified over 152 snus and 228 synthetic ONPs into the following flavor categories: "Tobacco", "Menthol/Mint", "Fruity", "Candy/Deserts", "Drink", "Aroma", "Spices", and "Mixed Flavors".

RESULTS

Based on total numbers, we found the most popular ONP flavors, sold as tobacco and menthol, to be among natural ONPs; among synthetic ONPs, fruity and menthol are the most prominent flavors, with varying concentrations of nicotine and other flavoring chemicals, including coolant WS-23. We also showed possible molecular targets and toxicities, due to exposure to ONPs, activating several signaling cascades such as AKT and NF-kappaB, which might possibly lead to apoptosis and epithelial mesenchymal transition (EMT).

CONCLUSIONS

Considering the marketing of ONP products with various flavor profiles and with most of these products containing tobacco/menthol/fruit flavor, it is likely to have regulation and a marketing disclaimer on some of these products. Further, it would be logical to determine how the market reacts in terms of compliance and non-compliance with flavor restrictions by the regulatory agencies.

Health effects of e-cigarettes and their use for smoking cessation from a vascular perspective

Tobacco consumption is one of the most important risk factors for cardiovascular disease. Despite all efforts to curb any form of smoking, the number of e-cigarette users is still rising more than tabacco smoking decreases. E-cigarettes are often advertised as less harmful than regular cigarettes and helpful for smoking cessation. But e-cigarettes are not risk-free and their use causes vascular damage. There is concern about long-term health risks of e-cigarettes or when non-smokers use them as first nicotine contact. Furthermore, their use for smoking cessation is discussed controversially. To optimize treatment and medical counselling of current smokers and e-cigarette users, we present an evidence-based overview of the most important issues of e-cigarette use from a vascular medicine point of view. The key messages are presented as a position statement of the German Society of Vascular Medicine and endorsed by the European Society of Vascular Medicine.

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

INTRODUCTION

The cardiovascular health effects of electronic nicotine delivery systems (ENDS) use are not well characterized, making it difficult to assess ENDS as a potential harm reduction tool for adults who use cigarettes.

AIMS AND METHODS

Using waves 1-5 of the Population Assessment of Tobacco and Health Study (2013-2019), we analyzed the risk of self-reported incident diagnosed myocardial infarction (MI; 280 incident cases) and stroke (186 incident cases) associated with ENDS and/or cigarette use among adults aged 40 + using discrete time survival models. We employed a time-varying exposure lagged by one wave, defined as exclusive or dual established use of ENDS and/or cigarettes every day or some days, and controlled for demographics, clinical factors, and past smoking history.

RESULTS

The analytic samples (MI = 11 031; stroke = 11 076) were predominantly female and non-Hispanic White with a mean age of 58 years. At baseline, 14.2% of respondents exclusively smoked cigarettes, 0.6% exclusively used ENDS, and 1.0% used both products. Incident MI and stroke were rare during follow-up (< 1% at each wave). Compared to no cigarette or ENDS use, exclusive cigarette use increased the risk of MI (aHR 1.99, 95% CI = 1.40-2.84) and stroke (aHR 2.26, 95% CI = 1.51-3.39), while exclusive ENDS use (MI: aHR 0.61, 95% CI = 0.12-3.04; stroke: aHR 1.74, 95% CI = 0.55-5.49) and dual use (MI: aHR 1.84, 95% CI = 0.64-5.30; stroke: aHR 1.12, 95% CI = 0.33-3.79) were not significantly associated with the risk of either outcome.

CONCLUSIONS

Compared to non-use, exclusive cigarette use was associated with an increased risk of self-reported incident diagnosed cardiovascular disease over a 5-year period, while ENDS use was not associated with a statistically significant increase in the outcomes.

IMPLICATIONS

Existing literature on the health effects of ENDS use has important limitations, including potential reverse causation and improper control for cigarette smoking. We accounted for these issues by using a prospective design and adjusting for current and former smoking status and cigarette pack-years. In this context, we did not find that ENDS use was associated with a statistically significant increase in self-reported incident diagnosed myocardial infarction or stroke over a 5-year period. While more studies are needed, this analysis provides an important foundation and key methodological considerations for future research on the health effects of ENDS use.

Clinical testing of the cardiovascular effects of e-cigarette substitution for smoking: a living systematic review

Some persons who smoke have substituted e-cigarettes for tobacco cigarettes, either completely or partially. What effect does this have on cardiovascular functioning? We conducted a living systematic review on human clinical studies measuring the cardiovascular effects of e-cigarette substitution for smoking. The Scopus, PubMed, and CENTRAL Cochrane Library databases were searched on January 31 and April 29, 2021. Three secondary searches and a grey literature search were conducted. Included study designs were randomized controlled trials, quasi-experimental clinical trials, and cohort studies. Risk of bias and study quality were evaluated with the JBI Critical Appraisal tools and the Oxford Catalogue of Bias. The systematic review covered 25 studies comprising 1810 participants who smoked. Twenty studies were rated at high risk of bias, and five as some concerns. A tabular synthesis by direction of effect was conducted due to heterogeneity in the data. Nearly two-thirds of the test analyses indicated that e-cigarette use had no significance difference compared with tobacco cigarettes on heart rate, blood pressure, and in other cardiovascular tests. In two studies, participants with hypertension experienced a clinically relevant reduction in systolic blood pressure after 1 year of e-cigarette use. E-cigarette substitution incurs no additional cardiovascular risks, and some possible benefits may be obtained, but the evidence is of low to very low certainty. An update search on May 30, 2022 retrieved five studies that did not alter our conclusion.Registration PROSPERO #CRD42021239094.

The E-cigarette or Vaping Product Use-Associated Lung Injury Epidemic: Pathogenesis, Management, and Future Directions: An Official American Thoracic Society Workshop Report

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.

Prevalence, Knowledge, and Attitudes among Health Professions Students toward the Use of Electronic Cigarettes

Healthcare professionals are standing against the widespread use of e-cigarettes among the population, especially young adults. E-cigarettes are generally introduced, especially via social media platforms, as a safer alternative to conventional cigarette smoking. The aim of this study was to measure the prevalence of e-cigarette use among healthcare professions students at the University of Jordan, as well as to explore their knowledge and attitudes toward the use of e-cigarettes. An anonymous Google-Form^®-based cross-sectional questionnaire was presented to potential participants at the University of Jordan. Students' responses were analyzed using SPSS^® 23.0 software. A total of 679 online surveys were completed. About 37.4% of students reported using e-cigarettes at least once in their lifetime and about 20% of students were current e-cigarette users. The multivariate analysis showed that the factors associated with E-cigarette smoking are being male, having mothers, siblings, or friends using e-cigarettes, having easy access to e-cigarettes, and having social media as the main source of knowledge regarding e-cigarettes. The relatively high acceptance level and use of e-cigarettes among health professions students should be an alarming sign to decision-makers to give more attention to legislation that controls tobacco products including e-cigarette selling and advertising.

Nicotine and novel tobacco products drive adverse cardiac remodeling and dysfunction in preclinical studies

Background

The heart undergoes structural and functional changes in response to injury and hemodynamic stress known as cardiac remodeling. Cardiac remodeling often decompensates causing dysfunction and heart failure (HF). Cardiac remodeling and dysfunction are significantly associated with cigarette smoking. Although cigarette smoking has declined, the roles of nicotine and novel tobacco products (including electronic cigarettes and heat-not-burn tobacco) in cardiac remodeling are unclear. In this perspective, we present evidence demonstrating maladaptive cardiac remodeling in nicotine-exposed mice undergoing hemodynamic stress with angiotensin (Ang)-II infusion and review preclinical literature linking nicotine and novel tobacco products with cardiac remodeling and dysfunction.

Methods

Adult, male C57BL/6J mice were exposed to room air or chronic, inhaled nicotine for 8 weeks. A subset of mice was infused with Ang-II via subcutaneous osmotic mini-pumps during the final 4 weeks of exposure. Left ventricular structure and function were assessed with echocardiography.

Results

Chronic, inhaled nicotine abrogated Ang-II-induced thickening of the left ventricular posterior wall, leading to reduced relative wall thickness. Ang-II infusion was associated with increased left ventricular mass index in both air- and nicotine-exposed mice.

Conclusions

These changes suggest a phenotypic shift from concentric hypertrophy to eccentric hypertrophy in nicotine-exposed, hemodynamically-stressed mice which could drive HF pathogenesis. These findings join a growing body of animal studies demonstrating cardiac remodeling and dysfunction following nicotine and electronic cigarette exposure. Further exploration is necessary; however, clinicians and researchers should not overlook these emerging products as potential risk factors in the pathogenesis of cardiac remodeling and associated diseases including HF.

E-Cigarettes Reexamined: Product Toxicity

The introduction of e-cigarettes, or electronic nicotine delivery systems (ENDS), has been accompanied by controversy regarding their safety and effectiveness as a cessation aid and by an explosion in their use by youth. Their use does not involve the combustion of tobacco and the creation of harmful combustion products; they have been seen as a "harm reduction" tool that may be of assistance in promoting smoking cessation. Recognition that ENDS can deliver an array of chemicals and materials with known adverse consequences has spurred more careful examination of these products. Nicotine, nitrosamines, carbonyl compounds, heavy metals, free radicals, reactive oxygen species, particulate matter, and "emerging chemicals of concern" are among the constituents of the heated chemical aerosol that is inhaled when ENDS are used. They raise concerns for cardiovascular and respiratory health that merit the attention of clinicians and regulatory agencies. Frequently cited concerns include evidence of disordered respiratory function, altered hemodynamics, endothelial dysfunction, vascular reactivity, and enhanced thrombogenesis. The absence of evidence of the consequences of their long-term use is of additional concern. Their effectiveness as cessation aids and beneficial impact on health outcomes continue to be examined. It is important to ensure that their production and availability are thoughtfully regulated to optimise their safety and permit their use as harm reduction devices and potentially as smoking-cessation aids. It is equally vital to effectively prevent them from becoming ubiquitous consumer products with the potential to rapidly induce nicotine addiction among large numbers of youth. Clinicians should understand the nature of these products and the implications of their use.

Medium- and longer-term cardiovascular effects of e-cigarettes in adults making a stop-smoking attempt: a randomized controlled trial

BACKGROUND

Smoking is a major risk factor for cardiovascular disease and smoking cessation reduces excess risk. E-cigarettes are popular for smoking cessation but there is little evidence on their cardiovascular health effect. Our objective was to compare the medium- and longer-term cardiovascular effects in smokers attempting to quit smoking using e-cigarettes with or without nicotine or prescription nicotine replacement therapy (NRT).

METHODS

This was a single-center, pragmatic three-arm randomized (1:1:1) controlled trial, which recruited adult smokers (≥ 10 cigarettes/day), who were willing to attempt to stop smoking with support (n = 248). Participants were randomized to receive behavioral support with either (a) e-cigarettes with 18 mg/ml nicotine, (b) e-cigarettes without nicotine, and (c) NRT. Flow-mediated dilation (%FMD) and peak cutaneous vascular conductance (CVCmax) responses to acetylcholine (ACh) and sodium nitroprusside (SNP), mean arterial pressure (MAP), and other outcomes were recorded at baseline, 3, and 6 months after stopping smoking. Data were analyzed using generalized estimating equations (GEE).

RESULTS

At 3- and 6-month follow-up, %FMD showed an improvement over baseline in all three groups (e.g., p < 0.0001 at 6 months). Similarly, ACh, SNP, and MAP improved significantly over baseline in all groups both at 3 and 6 months (e.g., ACh: p = 0.004, at 6 months).

CONCLUSIONS

Smokers attempting to quit experienced positive cardiovascular impact after both a 3- and 6-month period. None of the groups (i.e., nicotine-containing and nicotine-free e-cigarettes or NRT) offered superior cardiovascular benefits to the others.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03061253 . Registered on 17 February 2017.

Cardiopulmonary Consequences of Vaping in Adolescents: A Scientific Statement From the American Heart Association

Although the US Food and Drug Administration has not approved e-cigarettes as a cessation aid, industry has at times positioned their products in that way for adults trying to quit traditional cigarettes; however, their novelty and customizability have driven them into the hands of unintended users, particularly adolescents. Most new users of e-cigarette products have never smoked traditional cigarettes; therefore, understanding the respiratory and cardiovascular consequences of e-cigarette use has become of increasing interest to the research community. Most studies have been performed on adult e-cigarette users, but the majority of these study participants are either former traditional smokers or smokers who have used e-cigarettes to switch from traditional smoking. Therefore, the respiratory and cardiovascular consequences in this population are not attributable to e-cigarette use alone. Preclinical studies have been used to study the effects of naive e-cigarette use on various organ systems; however, almost all of these studies have used adult animals, which makes translation of health effects to adolescents problematic. Given that inhalation of any foreign substance can have effects on the respiratory and cardiovascular systems, a more holistic understanding of the pathways involved in toxicity could help to guide researchers to novel therapeutic treatment strategies. The goals of this scientific statement are to provide salient background information on the cardiopulmonary consequences of e-cigarette use (vaping) in adolescents, to guide therapeutic and preventive strategies and future research directions, and to inform public policymakers on the risks, both short and long term, of vaping.

Maternal nicotine exposure induces congenital heart defects in the offspring of mice

Maternal cigarette smoking is a risk factor for congenital heart defects (CHDs). Nicotine replacement therapies are often offered to pregnant women following failed attempts of smoking cessation. However, the impact of nicotine on embryonic heart development is not well understood. In the present study, the effects of maternal nicotine exposure (MNE) during pregnancy on foetal heart morphogenesis were studied. Adult female mice were treated with nicotine using subcutaneous osmotic pumps at 0.75 or 1.5 mg/kg/day and subsequently bred with male mice. Our results show that MNE dose-dependently increased CHDs in foetal mice. CHDs included atrial and ventricular septal defects, double outlet right ventricle, unguarded tricuspid orifice, hypoplastic left ventricle, thickened aortic and pulmonary valves, and ventricular hypertrophy. MNE also significantly reduced coronary artery size and vessel abundance in foetal hearts. Moreover, MNE resulted in higher levels of oxidative stress and altered the expression of key cardiogenic regulators in the developing heart. Nicotine exposure reduced epicardial-to-mesenchymal transition in foetal hearts. In conclusion, MNE induces CHDs and coronary artery malformation in mice. These findings provide insight into the adverse outcomes of foetuses by MNE during pregnancy.

E-cigarette exposure with or without heating the e-liquid induces differential remodeling in the lungs and right heart of mice

Various cardiopulmonary pathologies associated with electronic cigarette (EC) vaping have been reported. This study investigated the differential adverse effects of heating-associated by-products versus the intact components of EC aerosol to the lungs and heart of mice. We further dissected the roles of caspase recruitment domain-containing protein 9 (CARD9)-associated innate immune response and NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in EC exposure-induced cardiopulmonary injury. C57BL/6 wild type (WT), CARD9^-/-, and NLRP3^-/- mice were exposed to EC aerosol 3 h/day, 5 days/week for 6 month with or without heating the e-liquid with exposure to ambient air as the control. In WT mice, EC exposure with heating (EwH) significantly increased right ventricle (RV) free wall thickness at systole and diastole. However, EC exposure without heating (EwoH) caused a significant decrease in the wall thickness at systole. RV fractional shortening was also markedly reduced following EwH in WT and NLRP3^-/- mice. Further, EwH activated NF-κB and p38 MAPK inflammatory signaling in the lungs, but not in the RV, in a CARD9- and NLRP3-dependent manner. Levels of circulatory inflammatory mediators were also elevated following EwH, indicating systemic inflammation. Moreover, EwoH activated TGF-β1/SMAD2/3/α-SMA fibrosis signaling in the lungs but not the RV of WT mice. In conclusion, EC aerosol exposure following EwH or EwoH induced differential cardiopulmonary remodeling and CARD9 innate immune and NLRP3 inflammasome contributed to the adverse effects.

Tobacco use disorder and cardiovascular health

This narrative review examines the impact of cigarette smoking and the use of other tobacco and nicotine products on cardiovascular disease. Smoking increases the incidence of both acute and chronic cardiovascular diseases, and the harmful effects are substantially and relatively quickly reversible after quitting. Recommended cessation treatment includes offering pharmacotherapy, counseling which should emphasize the rapid risk reduction that occurs after quitting and adequate follow-up contacts. Although most research on cardiovascular disease in relation to tobacco use has focused upon cigarette smoking, we also review available data related to other combustible tobacco products, smokeless tobacco, electronic nicotine delivery systems and second-hand smoke. We discuss the implications of smoking on clinical management of patients with heart disease and newer developments with potential relevance to treatment of such patients.

From Tobacco Cigarettes to Electronic Cigarettes: The Two Sides of a Nicotine Coin

Tobacco smoking-related diseases, including cardiovascular disease, pulmonary disease, stroke, and cancer in multiple organ sites, are the leading causes of preventable death, worldwide. Youth electronic cigarette use (vaping) is an evolving public health problem in the United States and around the world. Many of the same toxicants and carcinogens present in tobacco smoke are also found in electronic cigarette vapor, although mostly at substantially lower levels. The reduced concentrations of these chemicals in electronic cigarette vapor may imply lower health risk; however, they cannot equate to no risk. To date, the long-term health consequences of vaping are largely unknown. This “Perspective” provides a concise chronology of events leading up to an unprecedented global challenge, namely the convergence of global tobacco epidemic and youth vaping epidemic. Current state of knowledge, outstanding questions in the field, present challenges, and future directions in research are highlighted. The existing data show a continued and dynamic evolution of the converged epidemics. The goal should be to prevent youth vaping while improving smoking cessation strategies. In smokers who are unable or unwilling to quit smoking, the objective should be to provide “provably” safe or less-harmful alternatives, which should “completely” or “substantially” substitute tobacco cigarettes.

Human Bronchial Epithelial Cell Culture Models for Cigarette Smoke and Vaping Studies

Despite the continuing public health efforts to stop or reduce smoking, cigarette smoke use remains popular in the youth and adult population. A recent surge in the use of electronic cigarette and vaping products has created another major health challenge in public health. There is an urgent need to use physiologically relevant models to study the health effect of smoking or vaping in human subjects. Airway diseases such as bronchitis (Landman et al., CMAJ 191:E1321-E1331, 2019; Goniewicz, et al. Harm Reduct J 17:91, 2020; Xie et al., JAMA Netw Open 3:e2020816, 2020) have been described in people who smoke, vape, or both. Here, we will describe methods to collect, expand, and culture human airway epithelial cells from endobronchial brushings and expose these cells cultured at the air-liquid interface to cigarette smoke or electronic cigarette vapor.