What are the respiratory effects of e-cigarettes?

Trends in E-cigarette Use in Callers to the Wisconsin Tobacco Quit Line

INTRODUCTION

E-cigarette use has been increasing for years with a limited understanding of how to help users quit. Quit lines are a potential resource for e-cigarette cessation. Our objective was to characterize e-cigarette users who call state quit lines and to examine trends in e-cigarette use by callers.

METHODS

This retrospective study examined data from adult callers to the Wisconsin Tobacco Quit Line from July 2016 through November 2020, including demographics, tobacco product use, motivations for use, and intentions to quit. Descriptive analyses were performed by age group with pairwise comparisons.

RESULTS

A total of 26,705 encounters were handled by the Wisconsin Tobacco Quit Line during the study period. E-cigarettes were used by 11% of callers. Young adults aged 18-24 had the highest rates of use at 30%, and their use rose significantly from 19.6% in 2016 to 39.6% in 2020. E-cigarette use among young adult callers peaked at 49.7% in 2019, coinciding with an outbreak of e-cigarette-related lung injury. Only 53.5% of young adult callers used e-cigarettes to "cut down on other tobacco," compared to 76.3% of adult callers aged 45-64 (P <0.05). Of all callers using e-cigarettes, 80% were interested in quitting.

CONCLUSIONS

E-cigarette use among callers to the Wisconsin Tobacco Quit Line has increased, driven largely by young adults. Most e-cigarette users who call the quit line want to quit. Thus, quit lines can serve an important role in e-cigarette cessation. A better understanding of strategies to help e-cigarette users quit is needed, particularly in young adult callers.

Menthol flavoring in e-cigarette condensate causes pulmonary dysfunction and cytotoxicity in precision cut lung slices

E-cigarette consumption is under scrutiny by regulatory authorities due to concerns about product toxicity, lack of manufacturing standards, and increasing reports of e-cigarette- or vaping-associated acute lung injury. In vitro studies have demonstrated cytotoxicity, mitochondrial dysfunction, and oxidative stress induced by unflavored e-cigarette aerosols and flavoring additives. However, e-cigarette effects on the complex lung parenchyma remain unclear. Herein, the impact of e-cigarette condensates with or without menthol flavoring on functional, structural, and cellular responses was investigated using mouse precision cut lung slices (PCLS). PCLS were exposed to e-cigarette condensates prepared from aerosolized vehicle, nicotine, nicotine + menthol, and menthol e-fluids at doses from 50 to 500 mM. Doses were normalized to the glycerin content of vehicle. Video-microscopy of PCLS revealed impaired contractile responsiveness of airways to methacholine and dampened ciliary beating following exposure to menthol-containing condensates at concentrations greater than 300 mM. Following 500 mM menthol-containing condensate exposure, epithelial exfoliation in intrabronchial airways was identified in histological sections of PCLS. Measurement of lactate dehydrogenase release, mitochondrial water-soluble-tetrazolium salt-1 conversion, and glutathione content supported earlier findings of nicotine or nicotine + menthol e-cigarette-induced dose-dependent cytotoxicity and oxidative stress responses. Evaluation of PCLS metabolic activity revealed dose-related impairment of mitochondrial oxidative phosphorylation and glycolysis after exposure to menthol-containing condensates. Taken together, these data demonstrate prominent menthol-induced pulmonary toxicity and impairment of essential physiological functions in the lung, which warrants concerns about e-cigarette consumer safety and emphasizes the need for further investigations of molecular mechanisms of toxicity and menthol effects in an experimental model of disease.

Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT

Background

Physical activity can support smoking cessation for smokers wanting to quit, but there have been no studies on supporting smokers wanting only to reduce. More broadly, the effect of motivational support for such smokers is unclear.

Objectives

The objectives were to determine if motivational support to increase physical activity and reduce smoking for smokers not wanting to immediately quit helps reduce smoking and increase abstinence and physical activity, and to determine if this intervention is cost-effective.

Design

This was a multicentred, two-arm, parallel-group, randomised (1 : 1) controlled superiority trial with accompanying trial-based and model-based economic evaluations, and a process evaluation.

Setting and participants

Participants from health and other community settings in four English cities received either the intervention (n = 457) or usual support (n = 458).

Intervention

The intervention consisted of up to eight face-to-face or telephone behavioural support sessions to reduce smoking and increase physical activity.

Main outcome measures

The main outcome measures were carbon monoxide-verified 6- and 12-month floating prolonged abstinence (primary outcome), self-reported number of cigarettes smoked per day, number of quit attempts and carbon monoxide-verified abstinence at 3 and 9 months. Furthermore, self-reported (3 and 9 months) and accelerometer-recorded (3 months) physical activity data were gathered. Process items, intervention costs and cost-effectiveness were also assessed.

Results

The average age of the sample was 49.8 years, and participants were predominantly from areas with socioeconomic deprivation and were moderately heavy smokers. The intervention was delivered with good fidelity. Few participants achieved carbon monoxide-verified 6-month prolonged abstinence [nine (2.0%) in the intervention group and four (0.9%) in the control group; adjusted odds ratio 2.30 (95% confidence interval 0.70 to 7.56)] or 12-month prolonged abstinence [six (1.3%) in the intervention group and one (0.2%) in the control group; adjusted odds ratio 6.33 (95% confidence interval 0.76 to 53.10)]. At 3 months, the intervention participants smoked fewer cigarettes than the control participants (21.1 vs. 26.8 per day). Intervention participants were more likely to reduce cigarettes by ≥ 50% by 3 months [18.9% vs. 10.5%; adjusted odds ratio 1.98 (95% confidence interval 1.35 to 2.90] and 9 months [14.4% vs. 10.0%; adjusted odds ratio 1.52 (95% confidence interval 1.01 to 2.29)], and reported more moderate-to-vigorous physical activity at 3 months [adjusted weekly mean difference of 81.61 minutes (95% confidence interval 28.75 to 134.47 minutes)], but not at 9 months. Increased physical activity did not mediate intervention effects on smoking. The intervention positively influenced most smoking and physical activity beliefs, with some intervention effects mediating changes in smoking and physical activity outcomes. The average intervention cost was estimated to be £239.18 per person, with an overall additional cost of £173.50 (95% confidence interval -£353.82 to £513.77) when considering intervention and health-care costs. The 1.1% absolute between-group difference in carbon monoxide-verified 6-month prolonged abstinence provided a small gain in lifetime quality-adjusted life-years (0.006), and a minimal saving in lifetime health-care costs (net saving £236).

Conclusions

There was no evidence that behavioural support for smoking reduction and increased physical activity led to meaningful increases in prolonged abstinence among smokers with no immediate plans to quit smoking. The intervention is not cost-effective.

Limitations

Prolonged abstinence rates were much lower than expected, meaning that the trial was underpowered to provide confidence that the intervention doubled prolonged abstinence.

Future work

Further research should explore the effects of the present intervention to support smokers who want to reduce prior to quitting, and/or extend the support available for prolonged reduction and abstinence.

Trial registration

This trial is registered as ISRCTN47776579.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 4. See the NIHR Journals Library website for further project information.

Clinical manifestations of EVALI in adolescents before and during the COVID-19 pandemic

INTRODUCTION

E-cigarette, or vaping, product use-associated lung injury (EVALI) results from inhaling the aerosol of e-cigarettes and has similar clinical features to coronavirus disease 2019 (COVID-19). EVALI case counts since the declaration of the COVID-19 pandemic is unknown.

METHODS

A retrospective electronic health record chart review of adolescents hospitalized at one institution with EVALI was conducted. Clinical characteristics and hospital course of patients hospitalized during the pandemic were compared to those prepandemic.

RESULTS

The clinical presentation of adolescents hospitalized prior-to (n = 19) and during the COVID-19 pandemic (n = 22) were similar with respect to constitutional, respiratory, and gastrointestinal symptoms. All patients hospitalized during the pandemic were tested for COVID-19 at least once. Only one patient had a positive SARS-CoV-2 RT-PCR test result. Thirty-one out of 39 patients treated with corticosteroids had clinical improvement within 24 h (79%). Patients hospitalized during the pandemic had a shorter median length of stay (5 vs. 7 days, p < 0.01), and were less often discharged with home oxygen (1 vs. 6 patients, p = 0.04). Pulmonary function tests improved pre- to postcorticosteroid treatment and postcorticosteroid to follow-up.

CONCLUSIONS

Eliciting a history of vaping in adolescents presenting with constitutional, respiratory, and gastrointestinal symptoms is important to identify EVALI cases, which have continued throughout the COVID-19 pandemic. A shorter length of stay with less need for mechanical ventilation and home oxygen in adolescents hospitalized during the pandemic may reflect increased familiarity with EVALI characteristics. Corticosteroids led to clinical and pulmonary function improvement.

Cigarette smoking and erectile dysfunction: an updated review with a focus on pathophysiology, e-cigarettes, and smoking cessation

Introduction

Cigarette smoking has major health implications and causes substantial damage to all organ systems. Approximately one-third of men are active smokers worldwide, and most men are unaware that cigarette smoking can contribute to erectile dysfunction (ED).

Objectives

This article aims to provide a comprehensive overview of research conducted on cigarette smoking and ED, with a particular focus on pathophysiology, electronic cigarettes (e-cigarettes), and smoking cessation.

Methods

A manual literature search was conducted on all research conducted on cigarette smoking and ED up to October 2022.

Results

Substantial evidence is now available showing that past and current cigarette smoking has dose-dependent associations with ED in studies controlling for age and important health comorbidities. Cigarette smoke contains nicotine, carbon monoxide, oxidant chemicals, and metals that can damage the endothelium and disrupt erectile processes. For current smokers, smoking abstinence can strengthen the endothelium and reverse diminished erectile function. The effect of e-cigarettes on endothelial damage and ED remains largely untested. E-cigarettes expose users to fine and ultrafine particles and toxins that can increase risk of cardiovascular injury, but these acute effects appear less potent than conventional cigarettes (long-term cardiovascular effects are still unknown). E-cigarettes are therefore likely to have less harmful effects on ED than conventional cigarettes.

Conclusions

Smoking cessation programs that focus on nicotine replacement therapy (transdermal patches, gum, or inhalers), behavioral counseling, social support, and education programs can be effective approaches to ED treatment in active smokers. Temporarily transferring from regular cigarettes to e-cigarettes—which transmit some of the same carcinogens as conventional cigarettes and are likely to have some long-term cardiovascular effects that disrupt erectile function—might also be useful for long-term smoking cessation and treatment of ED.

Effects of chronic electronic cigarettes exposure in inducing respiratory function decline and pulmonary tissue injury - A direct comparison to combustible cigarettes

BACKGROUND

Electronic cigarette (e-cig) use is increasing worldwide, especially among young individuals. Spirometry measures airflow obstruction and is the primary tool for diagnosing/monitoring respiratory diseases in clinical settings. This study aims to assess the effects of chronic e-cig exposure on spirometric traits, and directly compare to conventional combustible-cigarette (c-cig).

METHODS

We employed an e- and c-cig aerosol generation system that resembled human smoking/vaping scenario. Fifty 6-week old C57BL/6 mice were equally divided into five groups and exposed to clean air (control), e-cig aerosol (low- and high-dose), and c-cig aerosol (low- and high-dose), respectively, for 10 weeks. Afterwards, growth trajectory, spirometry and pulmonary pathology were analyzed.

RESULTS

Both e- and c-cig exposure slowed down growth and weight gain. Low dose e-cig exposure (1 h exposure per day) resulted in minimal respiratory function damage. At high dose (2 h exposure per day), e-cig exposure deteriorated 7 spirometry traits but by a smaller magnitude than c-cig exposure. For example, comparing to clean air controls, high dose e- and c-cig exposure increased inspiratory resistance by 24.3% (p = 0.026) and 66.7% (p = 2.6e-5), respectively. Low-dose e-cig exposure increased alveolar macrophage count but did not lead to airway remodeling. In contrast, even low-dose c-cig caused alveoli break down and thickening of the small airway, hallmarks of airway obstructive disease.

CONCLUSIONS

We conducted well-controlled animal exposure experiments assessing chronic e-cig exposure's effects on spirometry traits. Further, mechanistic study characterized airway remodeling, alveolar tissue lesion and inflammation induced by e- and c-cig exposure. Our findings provided scientific and public health insights on e-cig's health consequences, especially in adolescent users.

Effects of Electronic (E)-cigarette Vapor and Cigarette Smoke in Cultured Vocal Fold Fibroblasts

OBJECTIVE

The public use of electronic-cigarettes (e-cigs) is rapidly growing. When heated, e-cigs produce a vapor that is inhaled. The vocal folds are among the first tissues exposed to this insult. However, the impact of e-cigs on vocal fold health is almost entirely unknown. Our objective was to evaluate the effects of e-cig vapor on cultured human vocal fold fibroblasts (hVFFs), the primary cell type of the lamina propria. We compared the cellular effects of e-cig vapor without and with nicotine and conventional cigarette smoke.

STUDY DESIGN

In vitro.

METHODS

E-cig vapor extract (EVE) and cigarette smoke extract (CSE) were created by bubbling vapor and smoke, respectively, into the cell culture medium. hVFFs were exposed to EVE without or with nicotine or CSE for 24 hours. Untreated cells were used as a control group. Cells were harvested, and cytotoxicity, extracellular matrix and inflammatory gene expression, and DNA damage were assessed.

RESULTS

Undiluted EVE without and with nicotine reduced the viability of hVFFs to a cytotoxic level. CSE reduced hVFFs viability to a greater extent than EVE and induced DNA damage as measured by DNA double-strand breaks. No changes in gene expression were observed following EVE or CSE exposure.

CONCLUSION

EVE induces cytotoxicity in hVFFs. However, cellular responses were greater following exposure to CSE, suggesting cigarette smoke may induce more harm, at least in the short term. Findings from this investigation improve our understanding of responses of hVFFs to e-cigs and form the basis for an in vitro methodology to study the vocal fold responses to these products.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:139-146, 2023.

Impact of Electronic Cigarettes on the Upper Aerodigestive Tract: A Comprehensive Review for Otolaryngology Providers

Objective

The use and effects of electronic (e)-cigarettes (e-cigs) are particularly relevant for otolaryngology providers as tobacco plays a major role in benign and malignant diseases of the upper aerodigestive tract. This review aims to (1) summarize the recent policies regarding e-cigs and important patterns of use and (2) serve as a comprehensive resource for clinical providers on the known biologic and clinical effects of e-cigs on the upper aerodigestive tract.

Data Sources

PubMed/MEDLINE.

Review Methods

We conducted a narrative review on (1) general information on e-cig use and informative findings in the lower respiratory system and a comprehensive review on (2) the effects of e-cigs on cell and animal models and the clinical implications of these products on human health as is relevant to otolaryngology.

Conclusions

Although e-cigs are likely less harmful than conventional cigarettes, preliminary research on e-cigs suggest several deleterious effects including in the upper aerodigestive tract. Due to this, there has been increased interest in restricting e-cig usage, particularly among the adolescent population, and caution in recommending e-cigs to current smokers.

Implications for Practice

Chronic e-cig use is likely to have clinical implications. It is critical for otolaryngology providers to be aware of the rapidly changing regulations and use patterns regarding e-cigs and how e-cigs influence human health, particularly with regards to the upper aerodigestive tract, to accurately council patients regarding potential risks and benefits of use.

Analysis of vaporized caffeine in smoke from e-cigarettes using liquid chromatography-tandem mass spectrometry and clarification of minor components

PURPOSE

Electronic cigarettes (e-cigarettes) are used widely, and e-cigarettes containing caffeine (Caf) have recently become commercially available. However, no risk evaluation of these Caf-containing products has been performed to date. Such an evaluation requires a sensitive analytical method for quantifying Caf in smoke from e-cigarettes. The aim of this study was to establish a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying vaporized Caf from commercially available e-cigarettes, and to determine minor components related to Caf in cigarette smoke extract (CSE).

METHODS

A sampling system for Caf using a suction pump was designed and sampling conditions were optimized.

RESULTS

The optimized LC-MS/MS conditions allowed the sensitive determination of Caf in smoke with a limit of detection of 0.03 ng/mL at a signal-to-noise ratio of 3. The method was applied to CSEs from five e-cigarette products and the concentration of Caf ranged from 0.894 ± 0.090 to 3.32 ± 0.14 μg/mL smoke (n = 3). Additionally, minor components related to Caf, such as theobromine, theophylline, and paraxanthine, were detected in CSE and in e-liquid at very low concentrations, indicating that they were impurities in e-liquid and vaporized along with Caf.

CONCLUSION

This is the first report to determine the concentration of vaporized Caf using an LC-MS/MS method and to clarify several minor components in smoke from e-cigarettes.

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.

The main e-cigarette component vegetable glycerin enhances neutrophil migration and fibrosis in endotoxin-induced lung injury via p38 MAPK activation

We investigated the effects of vegetable glycerin (VG), a main e-cigarette constituent, on endotoxin-induced acute lung injury (ALI). Mice received intratracheal administration of 30% VG in phosphate buffered saline (PBS) vehicle or only PBS (control) for 4 days. On Day 5, mice received an intratracheal instillation of lipopolysaccharide (LPS) (LPS group and VG + LPS group) or PBS (VG group and control group). Lung histopathology, expression of chemokine receptors, and regulatory signaling were analyzed 24 h after the Day 5 treatment. VG significantly increased ALI-associated histopathological and fibrotic changes in both the VG group and LPS-induced ALI mice (VG + LPS group). Immunohistochemistry (IHC) and western blot analyses revealed that VG administration resulted in upregulation of neutrophil markers [lymphocyte antigen 6 complex locus G6D (Ly6G) and myeloperoxidase (MPO)] as well as upregulation of the expression of transforming growth factor-β (TGF-β), a central mediator of fibrogenesis, in the lungs of both VG and VG + LPS groups. VG enhanced the expression of adhesion molecules [very late antigen 4 (VLA-4) and vascular cell adhesion molecule 1 (VCAM-1)] and increased activation of p38 mitogen-activated protein kinase (p38 MAPK) to prompt neutrophil recruitment in the lungs of mice with ALI. Intraperitoneal administration of a p38 inhibitor attenuated these histopathological changes significantly as well as VG-induced upregulation in expression of Ly6G, MPO, VLA-4, VCAM-1, TGF-β, and collagen-1 in mice with ALI. In conclusion, VG enhances neutrophil chemotaxis and fibrosis and it amplifies the inflammatory response associated with LPS-induced ALI in the lungs via enhancement of p38 MAPK activity.

E-cigarette Flavors, Sensory Perception, and Evoked Responses

The chemosensory experiences evoked by flavors encompass a number of unique sensations that include olfactory stimuli (smell), gustatory stimuli (taste, i.e., salty, sweet, sour, bitter, and umami (also known as "savoriness")), and chemesthesis (touch). As such, the responses evoked by flavors are complex and, as briefly stated above, involve multiple perceptive mechanisms. The practice of adding flavorings to tobacco products dates back to the 17th century but is likely much older. More recently, the electronic cigarette or "e-cigarette" and its accompanying flavored e-liquids emerged on to the global market. These new products contain no combustible tobacco but often contain large concentrations (reported from 0 to more than 50 mg/mL) of nicotine as well as numerous flavorings and/or flavor chemicals. At present, there are more than 400 e-cigarette brands available along with potentially >15,000 different/unique flavored products. However, surprisingly little is known about the flavors/flavor chemicals added to these products, which can account for >1% by weight of some e-liquids, and their resultant chemosensory experiences, and the US FDA has done relatively little, until recently, to regulate these products. This article will discuss e-cigarette flavors and flavor chemicals, their elicited responses, and their sensory effects in some detail.

Electronic cigarettes use and 'dual use' among the youth in 75 countries: estimates from Global Youth Tobacco Surveys (2014-2019)

We report the country-level prevalence of awareness about electronic cigarette use, and 'dual use' and its association with age, sex, country income, and e-cigarette regulatory status. We analyzed the most recent Global Youth Tobacco Surveys done on nationally representative samples of school-going youth aged 13-15 years in 75 countries/territories. The weighted prevalence of 'awareness' (heard about e-cigarettes), 'ever use' (even tried a few puffs), 'current use' (during the last 30 days), and 'dual use' (e-cigarette use and cigarette smoking during the last 30 days) were estimated. Awareness was > 80% in 13 countries mostly from Europe Poland being the highest at 95.8% (95% CI 94.8- 96.6). In seven countries, 30-50% of the youth had ever used an e-cigarette, Italy was the highest at 55.1% (95%CI 51-3,58.9). In 30 countries, current e-cigarette use was > 10%, the highest of 35.1% (95%CI 32.4-38.0) in Guam. Awareness and use were highest in the European region (74.6% and 34.5%) and HIC (83.6% and 39.4%). Youth from HIC (compared to lMIC) and countries having restrictive e-cigarette regulations (compared to NRP) had 2.4 times (aOR 2.2.4, 95% CI 2.2, 2.7) and 1.8 times (aOR 1.8, 95% CI 1.6, 2.0) higher odds of being current e-cigarette users respectively. Youth in countries with the most restrictive e-cigarette regulations (compared to NRP) had 0.6 times lower odds of being current e-cigarette users (aOR 0.6, 95% CI 0.6, 0.7). Awareness and e-cigarette use varied by sex, country income level, and region. Continued global surveillance of youth e-cigarette use is needed for the formulation of e-cigarette regulatory policy. Awareness and use of e-cigarettes were higher among boys, in countries in Europe and America regions, and among those with higher income and restrictive policies, whereas it was lower in countries having the most restrictive policies. Higher awareness is strongly correlated with a trial and current use of e-cigarettes. E-cigarette marketing should be restricted, and continued surveillance of e-cigarette use is needed. Most restrictive policies such as the ban on e-cigarettes appear to reduce e-cigarette use among the youth.

Feasibility and acceptability of remote procedures to study tobacco product use and respiratory health: an observational study

OBJECTIVE

Obtaining ecologically valid biological samples is critical for understanding respiratory effects of tobacco use, but can be burdensome. In two diverse samples, we examined feasibility and acceptability of studying pulmonary function and respiratory health entirely remotely.

DESIGN

Observational feasibility and acceptability study.

SETTING AND PARTICIPANTS

Adults age 18-25 (Biomedical Respiratory Effects Associated through Habitual Use of E-Cigarettes [BREATHE] Study) and 21-65 (Adult IQOS Respiratory [AIRS] Study) recruited from previous research studies and advertisements in Southern California, USA (BREATHE (AIRS): N=77 (N=31) completed baseline, n=64 (n=20) completed feasibility and acceptability measures). Shared inclusion criteria for the two studies were ownership of a smartphone, willingness to download applications and English fluency. In addition, BREATHE participants reported one of three tobacco use patterns. AIRS participants smoked daily and were willing to use a heated tobacco product. Exclusion criteria were medical contraindications.

INTERVENTIONS

A 4-week study consisted of five virtual study visits, twice daily ecological momentary assessment diaries and spirometry assessments, and weekly Nasal Epithelial Lining Fluid and saliva collection. All study visits were conducted via video conference; study materials and biospecimens were exchanged via mail. Participants reported feasibility and acceptability of daily diaries, breath tests, biospecimen collection and shipments.

MEASURES

Surveys assessed perceptions of timing and overall experience of daily diaries and breath tests, difficulty of and overall experience with biospecimen collection, and experience sending and receiving shipments.

RESULTS

Most participants evaluated daily diaries and breath tests as manageable (62.5%-95.0%) and likeable (54.7%-70.0%). Breath tests were frequently described as 'interesting' (55.0%-57.8%) and 'easy' (25.0%-48.4%). Most participants reported that biospecimen collection was easy (50.0%-85.0%), and that shipments were easy to send (87.5%-95.0%), receive (95.3%-95.0%) and schedule (56.3%-60.0%). No participants received shipments in poor condition.

CONCLUSIONS

Remote research procedures may be feasible and acceptable to facilitate tobacco research studies, potentially resulting in more diverse samples of participants and more generalisable research results.

Biomarkers of Airway Immune Homeostasis Differ Significantly with Generation of E-Cigarettes

Rationale: Numerous studies have demonstrated that e-cigarettes can impact respiratory immune homeostasis; however, the extent of these effects remains an active area of investigation, and most previous studies were conducted with model systems or subjects exposed to third-generation e-cigarettes, such as vape pens and box mods. Objectives: Given the rise in popularity of nicotine-salt-containing pods and disposable e-cigarettes (fourth generation), we set out to better understand the respiratory effects of these newer e-cigarettes and compare their effects to early-generation devices. Methods: We collected induced sputum samples from a cohort of nonsmokers, smokers, third-generation e-cigarette users, and fourth-generation e-cigarette users (n = 20-30 per group) and evaluated the cellular and fluid-phase composition for markers of inflammation, host defense, and lung injury. Measurements and Main Results: Fourth-generation e-cigarette users had significantly more bronchial epithelial cells in the sputum, suggestive of airway injury. Concentrations of soluble intercellular adhesion molecule 1 (sICAM1) and soluble vascular cell adhesion molecule 1 (sVCAM1) were significantly lower in fourth-generation e-cigarette users in comparison with all other groups, and CRP (C-reactive protein), IFN-γ, MCP-1 (monocyte chemoattractant protein-1), MMP-2 (matrix metalloproteinase 2), uteroglobin, and VEGF (vascular endothelial growth factor) were significantly lower in fourth- versus third-generation e-cigarette users, suggestive of overall immune suppression in fourth-generation e-cigarette users. Predictive modeling also demonstrated clear separation between exposure groups, indicating that the overall mediator milieu is different between groups, particularly fourth-generation e-cigarette users. Conclusions: Our results indicate disrupted immune homeostasis in fourth-generation e-cigarette users and demonstrate that the biological effects of fourth-generation e-cigarette use are unique compared with those associated with previous-generation e-cigarettes.

The Respiratory Symptom Experience Scale (RSES): Quantitative Psychometric Assessment and Validation of a New Questionnaire to Assess Respiratory Symptoms in Current and Former Smokers RSES (Preprint)

BACKGROUND

Smokers often experience respiratory symptoms (eg, morning cough), and those who stop smoking, including those who do so by switching completely to electronic nicotine delivery systems (ENDS), may experience reductions in symptoms. Existing respiratory symptom questionnaires may not be suitable for studying these changes, as they are intended for patient populations, such as those with chronic obstructive pulmonary disease (COPD).

OBJECTIVE

This study aimed to develop a respiratory symptom questionnaire appropriate for current smokers and for assessing changes when smokers stop smoking.

METHODS

The Respiratory Symptom Experience Scale (RSES) was derived from existing instruments and subject matter expert input and refined through cognitive debriefing interviews (n=49). Next, for purposes of the quantitative psychometric evaluation, the RSES was administered to smokers (n=202), former smokers (no tobacco use in >6 months; n=200), and switchers (n=208, smokers who switched to ENDS for >6 months), all of whom had smoked for at least 10 years (mean age 33 years). Participants, who averaged 62 (SD 12) years of age, included 28% (173/610) with respiratory allergy symptoms and 17% (104/610) with COPD. Test-retest reliability was assessed by repeat assessment after 1 week in 128 participants.

RESULTS

A generalized partial credit model confirmed that the response options were ordered, and a parallel analysis using principal components confirmed that the scale was unidimensional. With allowance for 2 sets of correlated errors between pairs of items, a 1-factor graded response model fit the data. Discrimination parameters were approximately 1 or greater for all items. Scale reliability was 0.80 or higher across a broad range of severity (standardized scores -0.40 to 3.00). Test-retest reliability (absolute intraclass correlation) was good, at 0.89. RSES convergent validity was supported by substantial differences (Cohen d=0.74) between those with and without a diagnosis of respiratory disease (averaging 0.57 points, indicating that differences of this size or smaller represent meaningful differences). RSES scores also strongly differentiated those with and without COPD (d=1.52). Smokers' RSES scores were significantly higher than former smokers' scores (P<.001). Switchers' RSES scores were significantly lower than smokers' scores (P<.001) and no different from former smokers' scores (P=.34).

CONCLUSIONS

The RSES fills an important gap in the existing toolkit of respiratory symptom questionnaires; it is a reliable and valid tool to assess respiratory symptoms in adult current and former smokers, including those who have switched to noncombusted nicotine products. This suggests that the scale is sensitive to respiratory symptoms that develop in smokers and to their remission when smokers quit or switch to noncombusted nicotine products intended to reduce the harm of smoking. The findings also suggest that switching from cigarettes to ENDS may improve respiratory health.

Electronic Cigarette Use, Misuse, and Harm

Electronic cigarettes (e-cigarettes) are battery-powered devices that use heat to aerosolize a liquid containing a variety of substances (usually nicotine and/or cannabinoids, flavorings, and glycerol or propylene glycol base) that is then inhaled. E-cigarettes are rapidly evolving over time, so the true health effects of e-cigarettes are difficult to study and remain largely unknown. We review the effects of e-cigarettes on nicotine addiction and on pulmonary disease including the effects of dual use and switching from combustible cigarettes to e-cigarettes. Studies show that e-cigarette use can increase the risk to nicotine dependence and combustible tobacco use. Studies show an association between e-cigarette use and pulmonary disease. Some studies suggest reduced harm from e-cigarette use compared with smoking, but this requires further study. Most adults who use e-cigarettes also smoke cigarettes; epidemiologic studies suggest that the combination of e-cigarettes and cigarettes is more harmful than using either product alone.

Global frequency and epidemiological profile of electronic cigarette users: a systematic review

OBJECTIVE

Electronic cigarette (e-cigarette) use is growing significantly worldwide, especially among young people. This product has been associated with renormalizing smoking and hindering quit attempts in smokers. Moreover, among nonsmokers, it can lead to subsequent cigarette smoking and nicotine dependence. The present study aimed to assess the epidemiological profile of e-cigarette users worldwide.

STUDY DESIGN

A systematic review was performed using 3 main electronic databases (Medline/PubMed, SCOPUS, and EMBASE). Studies were independently assessed by 2 reviewers based on established eligibility criteria. The risk of bias was assessed using the MAStARI critical appraisal instrument.

RESULTS

From 4,496 records, 43 were included. Among the 1,238,392 participants, 132,786 (10.72%) were e-cigarette users. The age range with the highest percentage of e-cigarette users was 18-24 years old, with 40,989 (30.86%) males, 34,875 (26.26%) females, and 33.6% being current cigarette smokers. The highest prevalence of users was 52.88% in Croatia and 49.62% in New Zealand. Other possible correlations were observed with e-cigarette use, such as a high level of education.

CONCLUSION

Overall, e-cigarette users tended to be male young adults with a higher level of education. The highest prevalence of use was found in Croatia. This systematic review provides valuable information to improve the development of appropriate intervention strategies targeting e-cigarette users for more accurate anti-smoking actions.

[The e-cigarette - means of smoking cessation?]

After several years of declining tobacco consumption, the number of smokers in Germany is currently stagnating or rising again. The reasons seem to be manifold, e. g. stress caused by the pandemic with social isolation, rising cost of living and war in Europe.With tobacco use still widespread in the German population, evidence-based tobacco cessation is rarely implemented.According to recent studies, e-cigarettes are involved in the pathogenesis of lung disease, cardiac and vascular damage. In addition, their ingredients also have carcinogenic effects. However, clinical studies on long-term use are not yet available.E-cigarettes as a consumer product are not superior to nicotine replacement products and addiction-reducing medications recommended in guidelines. In the therapeutic setting, they are slightly more effective than nicotine replacement products. However, they are usually consumed continuously and thus perpetuate nicotine dependence. Their use increases the risk of relapse to tobacco smoking.Despite the various new approaches, such as Internet-based offerings, app, etc., talks and pharmacotherapy are the gold standard and more effective than any therapy on its own.

Development of LC-HRMS untargeted analysis methods for nasal epithelial lining fluid exposomics

BACKGROUND

The nasal mucosa, as a primary site of entry for inhaled substances, contains both inhaled xenobiotic and endogenous biomarkers. Nasal mucosa can be non-invasively sampled (nasal epithelial lining fluid "NELF") and analyzed for biological mediators. However, methods for untargeted analysis of compounds inhaled and/or retained in the nasal mucosa are needed.

OBJECTIVES

This study aimed to develop a high resolution LC-MS untargeted method to analyze collected NELF. Profiling of compounds in NELF samples will also provide baseline data for future comparative studies to reference.

METHODS

Extracted NELF analytes were injected to LC-ESI-MS. After spectrum processing, an in-house library provided annotations with high confidence, while more tentative annotation proposals were obtained via ChemSpider database matching.

RESULTS

The established method successfully detected unique molecular signatures within NELF. Baseline profiling of 27 samples detected 2002 unknown molecules, with 77 and 463 proposed structures by our in-house library and Chemspider matching. High confidence annotations revealed common metabolites and tentative annotations implied various environmental exposure biomarkers are also present in NELF.

SIGNIFICANCE

The experimental pipeline for analyzing NELF samples serves as simple and robust method applicable for future studies to characterize identities/effects of inhaled substances and metabolites retained in the nasal mucosa.

IMPACT STATEMENT

The nasal mucosa contains exogenous and endogenous compounds. The development of an untargeted analysis is necessary to characterize the nasal exposome by deciphering the identity and influence of inhaled compounds on nasal mucosal biology. This study established a high resolution LC-MS based untargeted analysis of non-invasively collected nasal epithelial lining fluid. Baseline profiling of the nasal mucosa (n = 27) suggests the presence of environmental pollutants, along with detection of endogenous metabolites. Our results show high potential for the analytical pipeline to facilitate future respiratory health studies involving inhaled pollutants or pharmaceutical compounds and their effects on respiratory biology.

Association between Harmful and Addictive Perceptions of E-Cigarettes and E-Cigarette Use among Adolescents and Youth-A Systematic Review and Meta-Analysis

BACKGROUND

Recognising the association between the perceived risks of e-cigarettes and e-cigarette usage among youth is critical for planning effective prevention and intervention initiatives; thus, a systematic review and meta-analysis were performed.

METHODS

Fourteen databases were searched for eligible studies from the Inception of database until March 2022 to examine the effect estimates of the association between perceptions of harmfulness and addictiveness and overall e-cigarette usage among adolescents and youth.

RESULTS

The meta-analysis showed that in comparison to non-users, young people who were ever e-cigarette users were two times more likely to disagree that e-cigarettes are harmful (OR: 2.20, 95% CI: 1.41-3.43) and perceived e-cigarettes as less harmful than tobacco cigarettes (OR: 2.01, 95% CI 1.47-2.75). Youths who were ever e-cigarette users were also 2.3 and 1.8 times more likely to perceive e-cigarettes as less addictive (OR: 2.28, 95% CI: 1.81-2.88) or perceive e-cigarettes as more addictive (OR: 1.82, 95% CI: 1.22-2.73) than tobacco cigarettes, as compared with non-users. The subgroup analysis reported that adolescents were more likely to believe that e-cigarettes are less harmful than tobacco cigarettes, while youth users perceived otherwise.

CONCLUSION

the risk perceptions of e-cigarettes are associated with e-cigarette use among adolescents and youth and could be the focus of health promotion to prevent and curb the uptake of e-cigarettes among young people.

Chemical Interactions and Cytotoxicity of Terpene and Diluent Vaping Ingredients

Vaping devices have risen in popularity since their inception in 2007. The practice involves using a variety of commercially available devices. Internal heating systems in devices aerosolize e-liquid formulations of complex mixtures including an active ingredient (e.g., THC, CBD, and nicotine), diluents (or cutting agents), solvents, and flavoring agents (e.g., terpenes and aldehydes). The vaping toxicology literature consists of cytotoxicity studies of individual chemicals and commercial formulas. Because of the variation of e-liquid composition, there is a limited understanding of the toxicity of ingredient combinations. This study analyzed the cytotoxic effects after exposure to individual and binary mixtures of a representative terpene (+-R-limonene) and diluent (triethyl citrate) on human lung cell models. Data were analyzed to determine the effects of 97:3 and 80:20% v/v (triethyl citrate/limonene) binary mixtures. BEAS-2B cells, a bronchial epithelial cell, and A549 cells, a type II alveolar epithelial cell, served as models for comparison. LC₅₀ values were calculated and isobolograms were used to assess chemical interactions. Results show that limonene was more cytotoxic than triethyl citrate. Isobolographic analyses confirmed that the 97:3% v/v mixture resulted in an antagonistic chemical interaction. The 80:20% v/v mixture resulted in a similar result. Further testing of different ratios of binary mixtures is needed for chemical interaction screening to inform safety assessments.

Tobacco use profiles by respiratory disorder status for adults in the wave 1-wave 4 population assessment of tobacco and health (PATH) study

•

Exclusive ENDS use is associated with a prior COPD diagnosis.

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Dual ENDS/cigarette use is associated with prior diagnoses of COPD and bronchitis.

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Analyses adjusted for behavioral health symptoms and other respiratory disorders.

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Complete tobacco cessation is most beneficial in reducing respiratory complications.

Limited evidence exists on the association between electronic nicotine delivery systems (ENDS) and chronic respiratory disorders. This study examines the association of combustible tobacco and ENDS use with chronic respiratory disorders among US adults. Public-use data from the Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013–2014), Wave 2 (2014–2015), Wave 3 (2015–2016), and Wave 4 (2016–2018) were pooled. Analyses focused on adults with W1–W4 respiratory disorder data and current tobacco use at W4, as well as youth entering the adult cohort at W2 through W4 (N = 26,072). We fit weighted multivariable logistic regression models for each respiratory outcome (asthma, COPD, bronchitis) using W4 longitudinal weights. Cigarette smokers (adjusted odds ratio [AOR] = 0.8, 95 % CI 0.7–0.9) were less likely to report an asthma diagnosis (p = 0.013). In contrast, ENDS users (AOR = 6.5, 95 % CI 3.7–11.5), cigarette smokers (AOR = 6.1, 95 % CI 4.0–9.1), dual users of cigarettes and ENDS (AOR = 5.4, 95 % CI 3.4–8.7), current users of non-cigarette combustible, smokeless, and polytobacco products (AOR = 4.4, 95 % CI 3.1–6.4), and former users of any product (AOR = 3.0, 95 % CI 1.9–4.7) had significantly elevated odds of reporting a diagnosis of COPD (p < 0.001). Similar patterns to COPD were observed for bronchitis (p < 0.001). Current and former tobacco use, including ENDS, were significantly associated with prevalence of self-reported COPD and bronchitis after controlling for demographic and psychosocial confounders.

Association of e-Cigarette Exposure with Pediatric Otitis Media Recurrence

OBJECTIVE

Otitis media (OM) is a common inflammatory disease spectrum in children and a leading cause of pediatric physician visits, antibiotic prescriptions and surgery. Tobacco exposure is associated with increased risk of OM recurrence, chronicity and surgeries. Tobacco products have changed dramatically in recent years with the advent of electronic cigarettes (e-cigarettes). While users frequently perceive vape as less harmful than traditional cigarettes, burgeoning evidence supports its contribution to respiratory pathologies. The consequences of secondhand exposure, particularly among children, are understudied. The aim of this study was to examine the association of e-cigarette emissions (EE) with OM recurrence and surgeries in the US.

METHODS

Questionnaire data regarding ear infections and tobacco exposure was gathered for all pediatric respondents of the National Health and Nutrition Examination Survey (NHANES) 2017 to 2018. Weighted analyzes and logistic regression models were used to assess associations.

RESULTS

Data was available for 2022 participants (aged 6-17); all were included for analyzes. Tobacco exposure was observed in 42%; 9% were exposed to EE. EE contributed to risk of ≥3 ear infections (OR = 1.61, 95% CI 1.01-2.58, P = .047). After adjustment for significant covariates (race and asthma), the association fell below significance (P = .081). No other significant associations were observed between ear infections, or tympanostomy tube insertion and exposure variables (EE, gestational or other household exposure).

CONCLUSIONS

Exposure to EE may confer greater risk of pediatric OM than previously identified factors such as household smoke, or gestational exposure. Further investigation of EE and its health implications in children is warranted.

LEVEL OF EVIDENCE

IV.

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.

What Are the Effects of Electronic Cigarettes on Lung Function Compared to Non-Electronic Cigarettes? A Systematic Analysis

Objective: The effects of e-cigarettes on lung function were compared between the e-cigarette and the non-e-cigarette group, as well as self-changes after inhaling e-cigarettes.

Method: From March 1st, 2022, relevant literature was selected from four databases through a predefined retrieval strategy. Strict literature screening and quality evaluation were conducted. The study followed PRISMA guidelines.

Results: Our results showed that CO (SMD: −1.48, 95%: −2.82–0.15) and FeNO (SMD: −0.66, 95%: −1.32, −0.01) were significantly decreased after e-cigarette usage. Only asthmatic smokers showed a statistically significant increase in flow resistance after inhaling e-cigarettes. Conversely, the decrease of FEV1/FVC% in the non-e-cigarette groups exceeded that in the e-cigarette group (SMD:1.18, 95%: 0.11–2.26). The degree of O₂ saturation decrease was also less than that for the cigarette groups (SMD:0.32, 95%: 0.04–0.59), especially when compared to the conventional cigarette group (SMD:0.56, 95%: 0.04–1.08).

Conclusion: The current findings indicate that short-term e-cigarette inhalation has a similar (but not significant) effect on lung function, as compared with non-e-cigarettes. More clinical studies are needed to explore the safety of inhaling e-cigarettes, especially in vulnerable populations.

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.

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.

New Insights into How JUUL™ Electronic Cigarette Aerosols and Aerosol Constituents Affect SARS-CoV-2 Infection of Human Bronchial Epithelial Cells

Background

The relationship between the use of tobacco products and SARS-CoV-2 infection is poorly understood and controversial. Most studies have been done with tobacco cigarettes, while few have examined the effect of electronic cigarettes (ECs) on SARS-CoV-2 infection. We tested the hypothesis that EC fluids and aerosols with high concentrations of nicotine promote SARS-COV-2 infection by increasing viral entry into human respiratory epithelial cells.

Methods

Responses of BEAS-2B cells to authentic JUUL™ aerosols or their individual constituents (propylene glycol (PG)/vegetable glycerin (VG) and nicotine) were compared using three exposure platforms: submerged culture, air-liquid-interface (ALI) exposure in a cloud chamber, and ALI exposure in a Cultex® system, which produces authentic heated EC aerosols. SARS-CoV-2 infection machinery was assessed using immunohistochemistry and Western blotting. Specifically, the levels of the SARS-CoV-2 receptor ACE2 (angiotensin converting enzyme 2) and a spike modifying enzyme, TMPRSS2 (transmembrane serine protease 2), were evaluated. Following each exposure, lentivirus pseudoparticles with spike protein and a green-fluorescent reporter were used to test viral penetration and the susceptibility of BEAS-2B cells to infection.

Results

Nicotine, EC fluids, and authentic JUUL™ aerosols increased both ACE2 levels and TMPRSS2 activity, which in turn increased viral particle entry into cells. While most data were in good agreement across the three exposure platforms, cells were more responsive to treatments when exposed at the ALI in the Cultex system, even though the exposures were brief and intermittent. In the Cultex system, PG/VG, PG/VG/nicotine, and JUUL™ aerosols significantly increased infection above clean air controls. However, both the PG/VG and JUUL™ treatments were significantly lower than nicotine/PG/VG. PG/VG increased infection only in the Cultex® system, which produces heated aerosol.

Conclusion

Our data are consistent with the conclusion that authentic JUUL™ aerosols or their individual constituents (nicotine or PG/VG) increase SARS-CoV-2 infection. The strong effect produced by nicotine was modulated in authentic JUUL aerosols, demonstrating the importance of studying mixtures and aerosols from actual EC products. These data support the idea that vaping increases the likelihood of contracting COVID-19.

Exposure to e-cigarette vapor extract induces vocal fold epithelial injury and triggers intense mucosal remodeling

Vaping has been reported to cause acute epiglottitis, a life-threatening airway obstruction induced by direct epithelial injury and subsequent inflammatory reaction. Here, we show that we were able to recapitulate this phenomenon in vitro. Exposure of human engineered vocal fold (VF) mucosae to 0.5% and 5% electronic cigarette (e-cigarette) vapor extract (ECVE) for 1 week induced cellular damage of luminal cells, disrupting homeostasis and innate immune responses. Epithelial erosion was likely caused by accumulation of solvents and lipid particles in the cytosol and intercellular spaces, which altered lipid metabolism and plasma membrane properties. Next, we investigated how the mucosal cells responded to the epithelial damage. We withdrew the ECVE from the experimental system and allowed VF mucosae to regenerate for 1, 3 and 7 days, which triggered intense epithelial remodeling. The epithelial changes included expansion of P63 (TP63)-positive basal cells and cytokeratin 14 (KRT14) and laminin subunit α-5 (LAMA5) deposition, which might lead to local basal cell hyperplasia, hyperkeratinization and basement membrane thickening. In summary, vaping presents a threat to VF mucosal health and airway protection, thereby raising further concerns over the safety of e-cigarette use. This article has an associated First Person interview with the first author of the paper.

On the toxicity of e-cigarettes consumption: Focus on pathological cellular mechanisms

Tobacco smoking remains without a doubt one of the leading causes of premature death worldwide. In combination with conventional protocols for smoking cessation, e-cigarettes have been proposed as a useful tool to quit smoking. Advertised as almost free of toxic effects, e-cigarettes have rapidly increased their popularity, becoming a sought-after device, especially among young people. Recently some health concerns about e-cigarette consumption are being raised. It is well known that they can release several toxic compounds, some of which are carcinogenic to humans, and emerging results are now outlining the risks related to the onset of respiratory and cardiovascular diseases and even cancer. The present review shows the emerging evidence about the role of technical components of the devices, the e-liquid composition as well as customization by consumers. The primary topics we discuss are the main toxicological aspects associated with e-cigarette consumption, focusing on the molecular pathways involved. Here it will be shown how exposure to e-cigarette aerosol induces stress/mitochondrial toxicity, DNA breaks/fragmentation following the same pathological pathways triggered by tobacco smoke, including the deregulation of molecular signalling axis associated with cancer progression and cell migration. Risk to fertility and pregnancy, as well as cardiovascular risk associated with e-cigarette use, have also been reported.

Tests for confounding with cigarette smoking in the association of E-cigarette use with respiratory disorder: 2020 National-Sample Data

Associations of e-cigarette use with respiratory disorder have been demonstrated but it has been unclear whether these are confounded by current or previous cigarette smoking. We address this question through studying different time frames for e-cigarette use and respiratory disorders in 2020 BRFSS data (N = 214,945). E-cigarette use and combustible cigarette smoking were classified into four categories: Participant never used either (Nonuse); used e-cigarettes/cigarettes but not in the past 30 days (Former Use), used in past 30 days on some days (Nondaily Use), or used past 30 days on all days (Daily Use). Contrasts for e-cigarette status and cigarette status (with nonuse as reference group) were entered with covariates in logistic regression with asthma or COPD as criterion. Stratified analyses of e-cigarette use were also performed for smokers and nonsmokers. In the total sample, results showed independent positive associations with both lifetime and current asthma for Former, Nondaily, and Daily e-cigarette use (mostly p < .0001) and the three cigarette indices. Significant positive associations with COPD were found for the three e-cigarette indices (p < .0001) and all the cigarette indices. Stratified analyses showed significant associations of e-cigarette use with respiratory disorder among nonsmokers as well as among smokers. We conclude that independent associations for former e-cigarette use (controlling for current/former smoking) and significant associations of e-cigarette use with respiratory disorder among nonsmokers indicate these associations are not confounded with cigarette smoking and suggest reverse causation is implausible. Findings for former use are discussed with reference to possible mechanisms including sensitization effects.

Health Effects of Electronic Cigarettes: An Umbrella Review and Methodological Considerations

E-cigarettes are often marketed as a safer alternative to combustible cigarettes. However, their health effects, especially those associated with long-term use, remain largely uncertain. We conducted an umbrella review of the cardiopulmonary and carcinogenic risks of e-cigarette use, distinguishing between short-term and long-term health effects. The search for systematic reviews was conducted across four electronic databases through 25 January 2022. Methodological quality was assessed using the AMSTAR-2 quality appraisal tool. Seventeen systematic reviews, including five meta-analyses, were included in our umbrella review. There was a clear underreporting of e-cigarette devices and e-liquid types, e-cigarette and cigarette exposure, and the health and smoking status of study participants. Overall, the findings suggest that short-term use of e-cigarettes may be associated with acute cardiopulmonary risks, although to a lesser extent than cigarette use. Long-term e-cigarette use may have pulmonary/respiratory benefits in those who switch from chronic cigarette smoking, particularly in individuals with asthma and chronic obstructive pulmonary disease (COPD). Evidence on intermediate and long-term carcinogenic effects is lacking. This umbrella review underscores the urgent need for systematic reviews with better adherence to established reporting guidelines, consistent definitions of duration of e-cigarette use, a focus on newer devices, and accounting for the impacts of former or current smoking.

Impact of vaping on respiratory health

Widespread uptake of vaping has signaled a sea change in the future of nicotine consumption. Vaping has grown in popularity over the past decade, in part propelled by innovations in vape pen design and nicotine flavoring. Teens and young adults have seen the biggest uptake in use of vape pens, which have superseded conventional cigarettes as the preferred modality of nicotine consumption. Relatively little is known, however, about the potential effects of chronic vaping on the respiratory system. Further, the role of vaping as a tool of smoking cessation and tobacco harm reduction remains controversial. The 2019 E-cigarette or Vaping Use-Associated Lung Injury (EVALI) outbreak highlighted the potential harms of vaping, and the consequences of long term use remain unknown. Here, we review the growing body of literature investigating the impacts of vaping on respiratory health. We review the clinical manifestations of vaping related lung injury, including the EVALI outbreak, as well as the effects of chronic vaping on respiratory health and covid-19 outcomes. We conclude that vaping is not without risk, and that further investigation is required to establish clear public policy guidance and regulation.

The First State Tobacco Flavor Ban: High School Tobacco Control Needs in a Changing Landscape

BACKGROUND

Despite recent tobacco control efforts, adolescent vaping remains an epidemic in the United States. The purpose of our study was to understand high school student vaping behaviors using the perceptions of Massachusetts school personnel during the critical window from when the Massachusetts statewide flavor ban legislation was passed in November 2019 through the first year of the COVID-19 pandemic.

METHODS

High school personnel throughout Massachusetts were invited to complete a cross-sectional survey. Analysis of survey responses was conducted in R.

RESULTS

A total of 162 respondents completed the survey representing 137 schools that draw enrollments from 216 (61%) of the 352 cities and towns in Massachusetts. The most popular products that respondents believed their students were using were JUULs (95.7%), other e-cigarettes (85.3%), and disposable vapes (79.6%). Following the flavor ban, the majority (90.7%) did not report an increase in combusted tobacco product use. All participants (100%) reported wanting more access to prevention and treatment resources.

CONCLUSIONS

Our findings suggest that a comprehensive flavor ban may be an effective tobacco control policy that does not appear to promote student switching from vaping products to combusted tobacco products. These data also indicate that schools report needing additional resources to address the vaping epidemic.

Secondhand nicotine vaping at home and respiratory symptoms in young adults

RATIONALE

Despite high prevalence of e-cigarette use (vaping), little is currently known regarding the health effects of secondhand nicotine vape exposure.

OBJECTIVE

To investigate whether exposure to secondhand nicotine vape exposure is associated with adverse respiratory health symptoms among young adults.

METHOD

We investigated the effect of secondhand nicotine vape exposure on annually reported wheeze, bronchitic symptoms and shortness of breath in the prospective Southern California Children Health Study cohort. Data were collected from study participants (n=2097) with repeated annual surveys from 2014 (average age: 17.3 years) to 2019 (average age: 21.9). We used mixed effect logistic regression to evaluate the association between secondhand nicotine vape and respiratory symptoms after controlling for relevant confounders.

RESULTS

Prevalence of secondhand nicotine vape increased from 11.7% to 15.6% during the study period in this population. Prevalence of wheeze, bronchitic symptoms and shortness of breath ranged from 12.3% to 14.9%, 19.4% to 26.0% and 16.5% to 18.1%, respectively, during the study period. Associations of secondhand nicotine vape exposure with bronchitic symptoms (OR 1.40, 95% CI 1.06 to 1.84) and shortness of breath (OR 1.53, 95% CI 1.06 to 2.21) were observed after controlling for vaping, active and passive exposure to tobacco or cannabis, and demographic characteristics (age, gender, race/ethnicity and parental education). Stronger associations were observed when analysis was restricted to participants who were neither smokers nor vapers. There were no associations with wheezing after adjustment for confounders.

CONCLUSION

Secondhand nicotine vape exposure was associated with increased risk of bronchitic symptoms and shortness of breath among young adults.

The Influence of Mental Health and Respiratory Symptoms on the Association Between Chronic Lung Disease and E-Cigarette Use in Adults in the United States

BACKGROUND

Adults with chronic lung disease use electronic cigarettes (e-cigarette) at higher rates than those without chronic lung disease. Because e-cigarettes have now been shown to cause adverse pulmonary effects and impair immune responses, it is particularly important to identify the factors that contribute to e-cigarette use in individuals with chronic lung disease. We tested whether mental health explains the association between chronic lung disease and e-cigarette use, and whether the association between chronic lung disease and e-cigarette use is conditional on the presence of respiratory symptoms.

METHODS

Data were obtained from the 2018 Behavioral Risk Factor Surveillance System. Logistic regression was used to test the association between chronic lung disease status and e-cigarette use when controlling for demographic variables and comorbidities. Structural equation modeling was then used to evaluate (a) whether the number of bad mental health days in the past 30 days explained the association between chronic lung disease and e-cigarette use, and (b) if respiratory symptoms moderated the association between chronic lung disease and e-cigarette use.

RESULTS

The prevalence of lifetime and current e-cigarette use was significantly higher in those with than in those without chronic lung disease, as was the number of bad mental health days in the past 30 days. Mediation analysis indicated a statistically significant indirect effect of chronic lung disease on the likelihood of e-cigarette use (lifetime and current) through mental health. However, our analyses did not indicate a statistically significant interaction between chronic lung disease and respiratory symptoms in the likelihood of e-cigarette use.

CONCLUSIONS

The association between chronic lung disease and e-cigarette use may be due, in part, to poorer mental health among individuals with chronic lung disease. These findings provide preliminary evidence that improving the mental health of individuals with chronic lung disease could reduce e-cigarette use in this vulnerable population.

Menthol in Electronic Cigarettes Causes Biophysical Inhibition of Pulmonary Surfactant

With an increasing prevalence of electronic cigarette (e-cigarette) use, especially among youth, there is an urgent need to better understand the biological risks and pathophysiology of health conditions related to e-cigarettes. A majority of e-cigarette aerosols are in the submicron size and would deposit in the alveolar region of the lung, where they must first interact with the endogenous pulmonary surfactant. To date, little is known whether e-cigarette aerosols have an adverse impact on the pulmonary surfactant. We have systematically studied the effect of individual e-cigarette ingredients on an animal-derived clinical surfactant preparation, bovine lipid extract surfactant, using a combination of biophysical and analytical techniques, including in vitro biophysical simulations using constrained drop surfactometry, molecular imaging with atomic force microscopy, chemical assays using carbon nuclear magnetic resonance and circular dichroism, and in silico molecular dynamics simulations. All data collectively suggest that flavorings used in e-cigarettes, especially menthol, play a predominant role in inhibiting the biophysical function of the surfactant. The mechanism of biophysical inhibition appears to involve menthol interactions with both phospholipids and hydrophobic proteins of the natural surfactant. These results provide novel insights into the understanding of the health impact of e-cigarettes and may contribute to a better regulation of e-cigarette products.

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.

Health Communication through Chinese Media on E-Cigarette: A Topic Modeling Approach

Background: Electronic cigarettes (e-cigarettes) have been a newsworthy topic in China. E-cigarettes are receiving greater consumer attention due to the rise of the Chinese e-cigarettes industry. In the past decade, e-cigarettes have been widely debated across the media, particularly their identity and their health effects. Objective: this study aims to (1) find the key topics in e-cigarette news and (2) provide suggestions for future media strategies to improve health communication. Method: We collected Chinese e-cigarettes news from 1 November 2015 to 31 October 2020, in the Huike (WiseSearch) database, using “e-cigarettes” (Chinese: “电子烟”) as the keyword. We used the Jieba package in python to perform the data cleaning process and the Dirichlet allocation (LDA) topic modeling method to generate major themes of the health communication through news content. Main finding: through an analysis of 1584 news articles on e-cigarettes, this paper finds 26 topics covered with 4 themes as regulations and control (n = 475, 30%), minor protection (n = 436, 27.5%), industry activities (n = 404, 25.5%), and health effects (n = 269, 17%). The peak and decline of the number of news articles are affected by time and related regulations. Conclusion: the main themes of Chinese news content on e-cigarettes are regulations and control, and minor protection. Newspapers should shoulder the responsibilities and play an important role in health communication with balanced coverage.

Association of Electronic Cigarette Use with Respiratory Symptom Development among U.S. Young Adults

Rationale: Electronic cigarette (e-cigarette) use is highly prevalent among young adults. However, longitudinal data assessing the association between e-cigarette use and respiratory symptoms are lacking. Objectives: To determine whether e-cigarette use is associated with the development of respiratory symptoms in young adults. Methods: Data are derived from the PATH (Population Assessment of Tobacco and Health) study waves 2 (2014-2015), 3 (2015-2016), 4 (2016-2018), and 5 (2018-2019). Young adults aged 18-24 years at baseline with no prevalent respiratory disease or symptoms were included in the analyses. Binary logistic regression models with a generalized estimating equation were used to estimate time-varying and time-lagged associations of e-cigarette use during waves 2-4, with respiratory symptom development approximately 12 months later at waves 3-5. Measurements and Main Results: The per-wave prevalence of former and current e-cigarette use was 15.2% and 5.6%, respectively. Former e-cigarette use was associated with higher odds of developing any respiratory symptom (adjusted odds ratio [aOR], 1.20; 95% confidence interval [CI], 1.04-1.39) and wheezing in the chest (aOR, 1.41; 95% CI, 1.08-1.83) in multivariable adjusted models. Current e-cigarette use was associated with higher odds for any respiratory symptom (aOR, 1.32; 95% CI, 1.06-1.65) and wheezing in the chest (aOR, 1.51; 95% CI, 1.06-2.14). Associations persisted among participants who never smoked combustible cigarettes. Conclusions: In this nationally representative cohort of young adults, former and current e-cigarette use was associated with higher odds of developing wheezing-related respiratory symptoms, after accounting for cigarette smoking and other combustible tobacco product use.

The youth e-cigarette epidemic: updates and review of devices, epidemiology and regulation

Adolescent e-cigarette use constitutes a major public health challenge that has reversed the steady progress made in the past three decades to reduce youth tobacco use in the United States (U.S.). Although the prevalence of e-cigarette use has declined in the past two years, 24% of 12th grade students and 8.9% of 8th grade students in 2021 used e-cigarettes or engaged in vaping of any kind in the prior 30 days. The current e-cigarette landscape is dominated by discrete and stylish pod-based e-cigarettes with varying capacity for customized nicotine delivery, vapor concealment, and child-appealing e-liquid flavors. E-cigarettes continue to evolve rapidly with innovative technology as manufacturers seek loopholes in regulatory efforts and to maximize existing marketing opportunities. Regulatory efforts so far have focused largely on marketing restrictions with enforcement decisions prioritizing smoking cessation potential of e-cigarettes for adult smokers over risk of nicotine addiction in adolescents. Disposable e-cigarette products advertising synthetic nicotine and menthol-containing products remain on the market and continue to gain popularity among adolescents. This article describes e-cigarette devices, provides an overview on epidemiology of U.S. adolescent e-cigarette use, and reviews the existing federal, state, and local e-cigarette regulations with future recommendations for stakeholders.

Association Between E-Cigarettes and Asthma in Adolescents: A Systematic Review and Meta-Analysis

INTRODUCTION

Numerous studies have revealed the relationship between E-cigarettes and asthma but have shown inconsistent results. This study systematically evaluated the potential association between E-cigarette use and asthma in adolescents.

METHODS

PubMed, Embase (Ovid), Cochrane Library, and the China Biological Medicine Database were searched for relevant articles published between database inception and February 28, 2021. The quality of included studies was evaluated using the Agency for Healthcare Research and Quality assessment, and a quantitative meta-analysis was conducted to pool outcomes of ORs with 95% CIs.

RESULTS

A total of 10 cross-sectional studies incorporating a total of 483,948 participants were included. All the study participants were middle- and high-school students with a mean age of 15-16 years. The median prevalence of ever E-cigarette use was 11.2% (range=2.2%, 45%), and that of current use was 7.5% (range=2.7%, 25%). Overall, E-cigarette use was associated with significantly higher odds of having asthma (pooled OR=1.31, 95% CI=1.22, 1.42) than nonuse, and both current use (OR=1.36, 95% CI=1.26, 1.48) and ever use (OR=1.20, 95% CI=1.12, 1.28) showed similar associations.

DISCUSSION

This study shows that both current and ever E-cigarette use have significant associations with asthma in adolescents. This knowledge might provide potential evidence for developing primary prevention strategies and serve as a reference for public health policy.

Treatable traits in COPD patients

There is no justification for a therapeutic nihilism in clinical practice because current management (pharmacological and non-pharmacological) of the patients with chronic obstructive pulmonary disease according to treatable traits is effective in decreasing their respiratory symptoms, increasing their exercise tolerance and capacity, improving their quality of life, preventing (and treating) many of their exacerbations and decreasing their mortality.

Youth perceptions of e-cigarette-related risk of lung issues and association with e-cigarette use

OBJECTIVE

E-cigarette use is associated with increased risk of negative health outcomes, including respiratory problems such as Coronavirus Disease 2019 (COVID-19). Nevertheless, adolescents and young adults (AYAs) continue to use e-cigarettes at alarming rates. We examined AYA's perceptions of the health harms of e-cigarettes in relation to respiratory problems and the associations between these perceptions and e-cigarette use.

METHOD

In May 2020, we conducted an online, national cross-sectional survey of AYAs aged 13 to 24 years old (N = 4,315; 65% female; 50% ever-users, 50% never-users) to assess e-cigarette use and perceptions of the risk of respiratory problems, COVID-19, and severe lung disease for AYAs with different levels of e-cigarette use.

RESULTS

In comparisons between AYAs with different levels of e-cigarette use, e-cigarette-related health risk perceptions were lower among ever-users compared to never-users and among ever-users who used e-cigarettes in the past 30 days compared to ever-users who did not use in the past 30 days. After controlling for demographics, AYAs were less likely to have used in the past 30 days if they agreed that young people are at risk of respiratory problems due to e-cigarette use (adjusted Odds Ratio [aOR] = .68, 95% confidence interval [CI; .59, .78]) and e-cigarettes are harmful for their health (aOR = .52, 95% CI [.30, .90]). AYAs were more likely to have used in the past 30 days if they believed that there is no hard evidence that e-cigarette use with nicotine increases risk of severe lung disease (aOR = 1.61, 95% CI [1.42, 1.82]) and that e-cigarette use is safer than smoking cigarettes (aOR = 1.26, 95% CI [1.11, 1.42]).

CONCLUSIONS

Among AYAs who had ever used e-cigarettes, those who did not believe that e-cigarette use increases the risks of respiratory problems were more likely to have used e-cigarettes in the past month. To bridge the gap between youth perceptions and emerging scientific evidence on e-cigarette-related health risks, prevention messaging should seek to explain how e-cigarette use is linked to respiratory problems and could affect COVID-19 outcomes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Aerosolized vitamin E acetate causes oxidative injury in mice and in alveolar macrophages

Although vitamin E acetate (VEA) is suspected to play a causal role in the development of electronic-cigarette, or vaping, product use-associated lung injury (EVALI), the underlying biological mechanisms of pulmonary injury are yet to be determined. In addition, no study has replicated the systemic inflammation observed in humans in a murine EVALI model, nor investigated potential additive toxicity of viral infection in the setting of exposure to vaping products. To identify the mechanisms driving VEA-related lung injury and test the hypothesis that viral infection causes additive lung injury in the presence of aerosolized VEA, we exposed mice to aerosolized VEA for extended times, followed by influenza infection in some experiments. We used mass spectrometry to evaluate the composition of aerosolized VEA condensate and the VEA deposition in murine or human alveolar macrophages. Extended vaping for 28 days versus 15 days did not worsen lung injury but caused systemic inflammation in the murine EVALI model. Vaping plus influenza increased lung water compared with virus alone. Murine alveolar macrophages exposed to vaped VEA hydrolyzed the VEA to vitamin E with evidence of oxidative stress in the alveolar space and systemic circulation. Aerosolized VEA also induced cell death and chemokine release and reduced efferocytotic function in human alveolar macrophages in vitro. These findings provide new insights into the biological mechanisms of VEA toxicity.