Evidence for harm reduction in COPD smokers who switch to electronic cigarettes

Partial amelioration of a chronic cigarette-smoke-induced phenotype in mice by switching to electronic cigarettes

Electronic cigarettes ("e-cigarettes") are often marketed as smoking cessation tools and are used by smokers to reduce/quit cigarette smoking. The objective of this study was to assess the health effects of switching to e-cigarettes after long-term smoking in a mouse model and compare these effects with continued smoking, or quitting entirely. Adult BALB/c mice were whole-body exposed to mainstream cigarette smoke (2 h/day, 5 days/week) for 12 weeks prior to switching to flavoured e-cigarette aerosol (50:50 propylene glycol and glycerine) containing 18 mg/mL nicotine (2 h/day and 5 days/week), continuing cigarette smoking (2 h/day and 5 days/week), or quitting entirely for an additional 2 weeks. We then assessed a range of respiratory health outcomes including lung function and structure, pulmonary inflammation and changes in gene expression in the lung. Switching to e-cigarettes led to improvements in some aspects of respiratory health in mice compared with continued smoking, such as reduced neutrophilic inflammation in the lung. However, total cellular lung inflammation was still elevated and lung function was still impaired, in terms of airway responsiveness to methacholine, for e-cigarette use compared with quitting. Larger effects were typically seen in female mice compared to male. This study shows that switching to e-cigarettes after long-term cigarette smoking leads to improvements in some aspects of respiratory health, such as neutrophilic inflammation and the volume dependence of lung function compared with continued smoking. However, switching to e-cigarettes was not as effective as quitting smoking entirely.

Switching to E-cigarettes as Harm Reduction Among Individuals With Chronic Disease Who Currently Smoke: Results of a Pilot Randomized Controlled Trial

INTRODUCTION

E-cigarettes (ECs) may be an effective harm reduction strategy for individuals with conditions like chronic obstructive pulmonary disease (COPD), asthma, coronary artery disease (CAD), and peripheral arterial disease who smoke combustible cigarettes (CCs). Our aim was to examine how individuals with chronic conditions transition from CCs to ECs and its impact on health outcomes.

AIMS AND METHODS

In a pilot randomized controlled trial (RCT), patients with COPD, asthma, and CAD/PAD who currently smoke CCs and have not used nicotine replacement therapy (NRT) or ECs in the past 14 days were randomized to receive ECs or combination NRT with behavioral counseling. Disease symptoms, acceptability/satisfaction (TSQM-9) and feasibility, and cigarettes per day (CPD), and/or EC use were collected at baseline, 3-, and 6 months. Descriptive statistics and a linear regression were conducted to explore changes in CPD and chronic condition-specific assessments (CAT, SAQ-7, and ACT) that assess COPD, asthma, and CAD/PAD symptom change.

RESULTS

At 3 months, the EC group (n = 63, mean CPD = 9 ± 11) reduced their CPD by 54% versus 60% in the NRT group (n = 58, mean CPD = 7 ± 6), p = .56. At 6 months, 17.5% had switched completely to ECs while 23% quit smoking in the NRT arm. CAT scores showed a significant 6-point reduction in the EC arm (p = .03). Participants scored an average of 69 ± 27 for EC effectiveness, 87 ± 23 for convenience, and 75 ± 27 for overall satisfaction.

CONCLUSIONS

This pilot study suggests that ECs may be a safer alternative for chronic condition patients using CCs and warrants further research on expected smoking cessation/reduction among individuals who use ECs.

IMPLICATIONS

The findings from this pilot RCT hold significant implications for chronic conditions such as COPD, asthma, CAD, and peripheral arterial disease who smoke CCs. The observed reduction in CPD and improvement in respiratory symptoms suggest that switching to ECs appears feasible and acceptable among those with chronic diseases. These results suggest that ECs may offer an alternative for individuals struggling to quit CC smoking through existing pharmacotherapies. This study supports further exploration of switching to ECs as a harm reduction strategy among CC users who have been unsuccessful at quitting by other means.

The effects of electronic cigarette use patterns on health-related symptom burden and quality of life: analysis of US prospective longitudinal cohort study data

Objective

This study aimed to examine the association between e-cigarette (EC) use patterns and health-related symptoms (fatigue, pain, and emotional problems) as well as general quality of life (QoL).

Methods

Data were analyzed from 7,225 adults across Waves 1-6 of the US Population Assessment of Tobacco and Health (PATH) study. Current combustible cigarette (CC) or EC use patterns included dual CC/EC use, exclusive EC use, non-current use of CC or EC, and exclusive CC smoking. Multivariate linear mixed-effects models were used to investigate longitudinal associations between EC use patterns, and symptom burdens/QoL scores.

Results

Those who were not currently smoking or vaping reported the lowest fatigue, pain, and emotional problems, and the best QoL, among the four groups (all p < 0.001). Compared to exclusive CC smoking, exclusive EC use was associated with a significant decrease of 0.065 units in average fatigue (95% confidence interval [CI]: -0.121, -0.009), of 0.206 units in average pain (95% CI: -0.355, -0.058), and of 0.103 units in average QoL scores (95% CI: -0.155, -0.051), with emotional problems similar over time.

Conclusion

Exclusive EC users had less health-related symptoms and better QoL than those who were exclusive CC smokers. This should be taken into account when assessing the harm reduction potential of ECs.

Switching Away From Smoking and Reduction in Cigarette Consumption Among U.S. Adult Purchasers of the JUUL System Across 24 Months Including Diverse Subpopulations Disproportionately Affected by Cigarette Smoking

INTRODUCTION

Electronic nicotine-delivery systems (ENDS) can reduce tobacco-related health risks for adults who smoke cigarettes (AWS) by facilitating complete switching away from cigarettes. However, little is known about ENDS use and switching among subpopulations that have been disproportionately affected by smoking.

AIMS AND METHODS

AWS (age ≥ 21 years) were recruited following their first purchase of a JUUL Starter Kit in 2018. Participants who self-reported switching (no past-30-day cigarette smoking) at 1-, 2-, 3-, 6-, 9-, 12-, 15-, 18-, 21-, and 24-month follow-ups. Percent switched and percent with substantial smoking reduction (≥50% decrease in cigarettes per day among those who continued smoking) were calculated. Analyses focused on racial and ethnic minorities, persons with low income and education levels, sexual minorities, and those with mental and physical health conditions.

RESULTS

Overall rates of switching away from cigarettes increased across follow-ups to 51.2% (month-12) to 58.6% (month-24, 87% of whom used ENDS). Among those who continued to smoke at 24 months, 45.4% reduced cigarettes per day by ≥ 50%. Rates of switching and substantial smoking reduction were largely similar across subgroups, with some statistically significant, but small, differences in month-24 switching rates (eg, education, mental and physical health conditions; switch rate range: 42%-57%).

CONCLUSIONS

AWS demonstrated progressively increasing switching rates over 2 years after purchasing JUUL products. Similar trends in switching and smoking reduction were observed across populations disproportionately affected by smoking. By facilitating switching and smoking reduction, ENDS products such as JUUL may provide an opportunity to reduce smoking-related harm among some populations disproportionately affected by smoking, potentially reducing tobacco-related health disparities.

IMPLICATIONS

ENDS have the potential to benefit population health if they can replace cigarettes. This benefit must extend to populations disproportionately affected by smoking. In this real-world study, 59% of JUUL purchasers reported complete switching 2 years later (no past-30-day smoking, with most continuing to use ENDS). Furthermore, 45% of those who continued to smoke reduced cigarette consumption by at least half. These rates of switching and smoking reduction were largely comparable across populations disproportionately affected by smoking (defined, eg, by ethnicity and income). ENDS can serve as an effective harm reduction strategy to complement current efforts to reduce tobacco-related disparities.

Effectiveness of e-cigarettes as a stop smoking intervention in adults: a systematic review

BACKGROUND

This systematic review aims to identify the benefits and harms of electronic cigarettes (e-cigarettes) as a smoking cessation aid in adults (aged ≥ 18 years) and to inform the development of the Canadian Task Force on Preventive Health Care's (CTFPHC) clinical practice guidelines on e-cigarettes.

METHODS

We searched Ovid MEDLINE®, Ovid MEDLINE® Epub Ahead of Print, In-Process & Other Non-Indexed Citations, PsycINFO, Embase Classic + Embase, and the Cochrane Library on Wiley. Searches were conducted from January 2016 to July 2019 and updated on 24 September 2020 and 25 January 2024. Two reviewers independently performed title-abstract and full-text screening according to the pre-determined inclusion criteria. Data extraction, quality assessments, and the application of Grading of Recommendations Assessment, Development and Evaluation (GRADE) were performed by one independent reviewer and verified by another.

RESULTS

We identified 18 studies on 17 randomized controlled trials that compared e-cigarettes with nicotine to e-cigarettes without nicotine and e-cigarettes (with or without nicotine) to other interventions (i.e., no intervention, waitlist, standard/usual care, quit advice, or behavioral support). Considering the benefits of e-cigarettes in terms of smoking abstinence and smoking frequency reduction, 14 studies showed small or moderate benefits of e-cigarettes with or without nicotine compared to other interventions; although, with low, very low or moderate evidence certainty. With a focus on e-cigarettes with nicotine specifically, 12 studies showed benefits in terms of smoking abstinence when compared with usual care or non-nicotine e-cigarettes. In terms of harms following nicotine or non-nicotine e-cigarette use, 15 studies reported mild adverse events with little to no difference between groups and low to very low evidence certainty.

CONCLUSION

The evidence synthesis on the e-cigarette's effectiveness shows data surrounding benefits having low to moderate evidence certainty for some comparisons and very low certainty for others, indicating that e-cigarettes may or probably increase smoking cessation, whereas, for harms, there is low to very low evidence certainty. Since the duration for outcome measurement varied among different studies, it may not be long-term enough for Adverse Events (AEs) to emerge, and there is a need for more research to understand the long-term benefits and potential harms of e-cigarettes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018099692.

The chemical memory of smoking tobacco

The concentration in urine of N-acetyl-hydroxy-propyl-cisteine (3HPMA), an acrolein metabolite, has been employed as a marker of the risk of illness of smokers and the relative concentration of creatinine has been evaluated to verify the effect of moving from the practice of burning tobacco to nicotine vaping. From the results concerning the urine samples of 38 subjects, collected from 2021 to 2023 and analyzed by LC-MS/MS, corresponding to 5 active smokers, 13 previously heavy smokers who replaced traditional tobacco by vaping, and 20 non-smokers, a dramatic reduction was found in 3HPMA/creatinine in urine. 3HPMA varied from values of 2150-3100 μg gcreatinine-1 to levels of 225-625 μg gcreatinine-1 found for non-smokers, with the time decay described by the equation y = 0.3661x2 - 94.359x + 6246.4 (R2: 0.757), providing a time of approximately 10 years for tobacco memory after the cessation of the consumption of burned tobacco.

Effects of Combustible Cigarettes and Electronic Nicotine Delivery Systems on the Development and Progression of Chronic Lung Inflammation in Mice

INTRODUCTION

Although detrimental effects of combustible cigarettes (CCs) on the progression of lung inflammatory diseases are well known, changes in electronic nicotine delivery systems (ENDS)-exposed lung-infiltrated immune cells are still unrevealed.

AIMS AND METHODS

The analysis of blood gas parameters, descriptive and quantitative histology of lung tissues, determination of serum cytokines, intracellular staining, and flow cytometry analysis of lung-infiltrated immune cells were used to determine the differences in the extent of lung injury and inflammation between mice from experimental (CC and ENDS-exposed animals) and control groups (Air-exposed mice).

RESULTS

Continuous exposition to either CCs or ENDS induced severe systemic inflammatory response, increased activation of NLRP3 inflammasome in neutrophils and macrophages and enhanced dendritic cell-dependent activation of Th1 and Th17 cells in the lungs. ENDS induced less severe immune response than CCs. Serum concentrations of inflammatory cytokines were significantly lower in the samples of ENDS-exposed mice. Compared to CCs, ENDS recruited lower number of circulating leukocytes in injured lungs and had less capacity to induce CD14/TLR2-dependent activation of NLRP3 inflammasome in lung-infiltrated neutrophils and macrophages. ENDS-primed dendritic cells had reduced capacity for the generation of Th1 and Th17 cell-driven lung inflammation. Accordingly, extensive immune cell-driven lung injury resulted in severe respiratory dysfunction in CCs-exposed mice, while ENDS caused moderate respiratory dysfunction in experimental animals.

CONCLUSIONS

Continuous exposition to either CCs or ENDS induced immune cell-driven lung damage in mice. ENDS triggered immune response, which was less potent than inflammatory response elicited by CCs and, therefore, caused less severe lung injury and inflammation.

IMPLICATIONS

This is the first study that compared the effects of CCs and ENDS on lung-infiltrated immune cells. Although both CCs and ENDS elicited systemic inflammatory response, immune cell-driven lung injury and inflammation were less severe in ENDS-exposed than in CC-exposed animals. Continuous exposition to ENDS-sourced aerosols was less harmful for respiratory function of experimental animals than CC-derived smoke.

Impact of electronic cigarette usage on the onset of respiratory symptoms and COPD among Chinese adults

The prevalence of dual usage and the relatively low cessation rate among e-cigarette (EC) users suggest that ECs have not demonstrated significant effectiveness as a smoking cessation tool. Furthermore, there has been a substantial increase in the prevalence of EC usage in recent years. Therefore, the objective of this study is to investigate the association between EC use and the incidence of respiratory symptoms and chronic obstructive pulmonary disease (COPD). A total of 10,326 participants aged between 20 and 55 years, without any respiratory diseases or COPD, were recruited for the study. These individuals attended employee physical examinations conducted at 16 public hospitals in Hebei province, China from 2015 to 2020. Logistic regression models were utilized to assess the association between EC use and the risk of respiratory symptoms and COPD using risk ratios along with their corresponding 95% confidence intervals. Restricted cubic spline functions were employed to investigate the dose-response non-linear relationship. The robustness of the logistic regression models was evaluated through subgroup analyses, and sensitivity analyses. During the 5-year follow-up period, a total of 1071 incident cases of respiratory symptoms and 146 incident cases of COPD were identified in this cohort study. After adjusting for relevant confounding factors, EC users demonstrated a respective increase in the risk of reporting respiratory symptoms and COPD by 28% and 8%. Furthermore, dual users who used both ECs and combustible cigarettes exhibited an elevated risk of incident respiratory symptoms and COPD by 41% and 18%, respectively, compared to those who had never used non-users of any cigarette products. The association between daily EC consumption and the development of respiratory symptoms, as well as COPD, demonstrated a significant J-shaped pattern. The potential adverse association between the consumption of ECs, particularly when used in combination with combustible cigarettes, and the development of respiratory symptoms and COPD necessitates careful consideration. Policymakers should approach ECs cautiously as a prospective smoking cessation tool.

Respiratory health effects of e-cigarette substitution for tobacco cigarettes: a systematic review

BACKGROUND

E-cigarettes (electronic nicotine delivery system, ENDS) have been presented as a harm reduction strategy for people who smoke tobacco cigarettes but who cannot achieve abstinence, or for those who wish to continue to enjoy nicotine and the habit of smoking. What are the health effects of the substitution of ENDS for tobacco cigarettes? This systematic review evaluates the evidence of human clinical tests on the respiratory effects of ENDS use in participants who smoke tobacco cigarettes.

METHODS

A registered and published protocol was developed conforming to PRISMA 2020 and AMSTAR2 standards. The literature search was conducted in PubMed, Scopus, and the CENTRAL Cochrane Library and updated to May 2022. Three supplementary searches and a grey literature search were performed. Studies were evaluated with the JBI quality tools and the Oxford Catalogue of Bias. Due to the heterogeneity (diversity) of the studies, a narrative data synthesis was performed on the test findings plus three sub-group analyses.

RESULTS

The review consists of sixteen studies and twenty publications. Spirometry tests comprised the majority of the data. In total, 66 respiratory test measurements were reported, out of which 43 (65%) were not significant. Statistically significant findings were mixed, with 9 tests showing improvements and 14 measuring declines, none of which was clinically relevant. Ten studies were rated at a high risk of bias, and six had some concerns primarily due to inadequate research designs and the conduct of the studies. Reporting bias was documented in thirteen studies.

CONCLUSIONS

Most of the studies showed no difference in respiratory parameters. This indicates that ENDS substitution for smoking likely does not result in additional harm to respiratory health. Due to the low quality of the studies, confidence in the conclusions is rated as low. Robust studies with a longer duration and sufficient power are required to validate any potential benefits or possible harms of ENDS substitution. Registration PROSPERO #CRD42021239094, International Registered Report Identifier (IRRID): DERR1-10.2196/29084.

Third-Hand Exposure to E-Cigarette Vapour Induces Pulmonary Effects in Mice

In the last decade, e-cigarette usage has increased, with an estimated 82 million e-cigarette users globally. This is, in part, due to the common opinion that they are "healthier" than tobacco cigarettes or simply "water vapour". Third-hand e-vapour exposure is the chemical residue left behind from e-cigarette aerosols, which is of concern due to its invisible nature, especially among young children. However, there is limited information surrounding third-hand e-vapour exposure. This study aimed to investigate the pulmonary effects of sub-chronic third-hand e-vapour exposure in a murine model. BALB/c mice (4 weeks of age) were exposed to a towel containing nicotine free (0 mg) e-vapour, nicotine (18 mg) e-vapour, or no e-vapour (sham) and replaced daily for 4 weeks. At the endpoint, lung function was assessed, and bronchoalveolar lavage fluid and lungs were collected to measure inflammation and fibrosis. Mice exposed to third-hand e-vapour without nicotine had alveolar enlargement compared to sham exposed controls. Mice exposed to third-hand e-vapour with nicotine had reduced bronchial responsiveness to provocation, increased epithelial thickening in large airways, increased epithelial layers in small airways, alveolar enlargement, and increased small airway collagen deposition, compared to sham exposed controls. In conclusion, our study shows that third-hand e-vapour exposure, particularly in the presence of nicotine, negatively affects the lung health of mice and highlights the need for greater public awareness surrounding the dangers of third-hand exposure to e-cigarette vapour.

Smoking cessation and vaccination

A significant proportion of COPD patients (∼40%) continue smoking despite knowing that they have the disease. Smokers with COPD exhibit higher levels of nicotine dependence, and have lower self-efficacy and self-esteem, which affects their ability to quit smoking. Treatment should be adapted to the needs of individual patients with different levels of tobacco dependence. The combination of counselling plus pharmacotherapy is the most effective cessation treatment for COPD. In patients with severe COPD, varenicline and bupropion have been shown to have the highest abstinence rates compared with nicotine replacement therapy. There is a lack of evidence to support that smoking cessation reduction or harm reduction strategies have benefits in COPD patients. The long-term efficacy and safety of electronic cigarettes for smoking cessation need to be evaluated in high-risk populations; therefore, it is not possible to recommend their use for smoking cessation in COPD. Future studies with the new generation of nicotine vaccines are necessary to determine their effectiveness in smokers in general and in COPD patients.

Attempts to quit smoking, use of smoking cessation methods, and associated characteristics among COPD patients

We explored past-year quit attempts, cessation methods used, and associations with sociodemographic, smoking, and health-related characteristics among smoking patients with chronic obstructive pulmonary disease (COPD) in Germany. Cross-sectional survey data of 509 past-year smokers (current smokers and ≤12 months abstinent) with COPD (ICD-10 code J44.x and FEV1/FVC <0.70) from 19 pulmonary primary care practices were used. Associations were explored between age, sex, educational qualification, lung function, urges to smoke, psychological distress, and (a) ≥1 past-year quit attempt (yes/no), (b) use of ≥1 evidence-based smoking cessation method (yes/no). Of all patients, 48.5% (n = 247, 95% confidence interval (CI) 44.2–52.9) reported ≥1 past-year quit attempt. Such an attempt was positively associated with the male sex (Odds Ratio (OR) = 1.50, 95% CI 1.01–2.24) and negatively associated with time spent with urges to smoke (OR = 0.69, 95% CI 0.52–0.91). During the most recent past-year quit attempt, one-third of the patients used ≥1 evidence-based smoking cessation method (31.2%, 95% CI 25.4–37.0), which was positively associated with the strength of urges to smoke (OR = 1.62, 95% CI 1.09–2.41). Combined behavioural and pharmacological treatments were used by 4.0% (n = 10, 95% CI 1.6–6.5). Electronic cigarettes were used most frequently (21.5%, 95% CI 16.3–26.6). Although a high proportion of COPD patients in German pulmonary primary care attempt to quit smoking, only a few of them use evidence-based methods as assistance for quitting.

Electronic cigarette liquids impair metabolic cooperation and alter proteomic profiles in V79 cells

Background

Although still considered a safer alternative to classical cigarettes, growing body of work points to harmful effects of electronic cigarettes (e-cigarettes) affecting a range of cellular processes. The biological effect of e-cigarettes needs to be investigated in more detail considering their widespread use.

Methods

In this study, we treated V79 lung fibroblasts with sub-cytotoxic concentration of e-cigarette liquids, with and without nicotine. Mutagenicity was evaluated by HPRT assay, genotoxicity by comet assay and the effect on cellular communication by metabolic cooperation assay. Additionally, comprehensive proteome analysis was performed via high resolution, parallel accumulation serial fragmentation-PASEF mass spectrometry.

Results

E-cigarette liquid concentration used in this study showed no mutagenic or genotoxic effect, however it negatively impacted metabolic cooperation between V79 cells. Both e-cigarette liquids induced significant depletion in total number of proteins and impairment of mitochondrial function in treated cells. The focal adhesion proteins were upregulated, which is in accordance with the results of metabolic cooperation assay. Increased presence of posttranslational modifications (PTMs), including carbonylation and direct oxidative modifications, was observed. Data are available via ProteomeXchange with identifier PXD032071.

Conclusions

Our study revealed impairment of metabolic cooperation as well as significant proteome and PTMs alterations in V79 cells treated with e-cigarette liquid warranting future studies on e-cigarettes health impact.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02102-w.

Transcriptomic Evidence That Switching from Tobacco to Electronic Cigarettes Does Not Reverse Damage to the Respiratory Epithelium

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

Developments in smoking cessation interventions for patients with chronic obstructive pulmonary disease in the past 5 years: a scoping review

INTRODUCTION

Smoking cessation is the most effective strategy for slowing the progression of chronic obstructive pulmonary disease (COPD). However, COPD patients find it difficult to quit smoking with standard cessation interventions.

AREAS COVERED

A scoping review of smoking cessation for COPD patients was conducted by searching the MEDLINE, Embase, and Cochrane Library databases for all studies published between 1 January 2016 and 22 September 2021. Four themes were set up and 47 studies were included eventually. The majority of the included studies (61.7%, 29/47) investigated efficacy and effectiveness, including new strategies for extended treatment and mobile health (mHealth) delivery approach. Studies examining accessibility and utilization (31.9%, 15/47), safety (10.6%, 5/47), and health economics (6.4%, 3/47) were also reviewed. The quality of the included randomized controlled trials was also evaluated.

EXPERT OPINION

Pharmacotherapy combined with behavioral interventions delivered via mHealth may be a promising strategy to help COPD smokers quit. However, the overall quality of the current studies is poor, making it challenging for clinicians to make informed decisions. Future high-quality studies are needed to provide conclusive evidence on the optimal pharmacotherapies and the most cost-effective comprehensive smoking cessation interventions, particularly those integrated into disease management for smokers with COPD.

Biomarkers of Exposure and Biomarkers of Potential Harm in Adult Smokers Who Switch to e-Vapor Products Relative to Cigarette Smoking in a 24-week, Randomized, Clinical Trial

INTRODUCTION

Long-term health effects of e-vapor products (EVPs) are not well-established. We compared biomarkers of exposure (BoE) to select harmful and potentially harmful constituents and biomarkers of potential harm (BoPH) in adult smokers who switched to EVPs versus continued smoking for 24 weeks.

METHODS

Adult smokers (n = 450, >10 cigarettes per day for ≥10 years) were randomly assigned to continue smoking (control) or switch to one of two cartridge-based EVPs (test 1: classic; test 2: menthol, 4% nicotine). BoE and BoPH were measured at baseline and 12 weeks. The results presented here are from a subset of 150 control and EVP subjects (switchers with exhaled carbon monoxide <8 ppm and <10% baseline cigarettes per day) followed for 24 total weeks.

RESULTS

Total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and carboxyhemoglobin were significantly reduced (p < .0001) in tests 1 and 2 at 24 weeks. Urinary nicotine equivalents were not statistically significantly different between the control and EVP groups. At week 24, statistically significant reductions (p < .05) were observed for white blood cell counts, 11-dehydrothromboxane β2, and sICAM in both test groups, and there were several significant changes in measures of pulmonary function. High-density lipoprotein cholesterol and 8-epi-prostaglandin-F2α were directionally favorable in both EVP groups versus control.

CONCLUSIONS

We demonstrate that significant reductions of selected harmful and potentially harmful constituents in EVP aerosol results in significant reductions in BoEs and favorable changes in BoPHs after switching to EVPs for 24 weeks. These changes approached those reported for smoking cessation, suggesting that switching to exclusive use of the EVPs may be less harmful than continuing smoking.

IMPLICATIONS

Cigarette smoking causes serious diseases. Switching from cigarettes to a noncombustible product is a potential harm reduction pathway for adult smokers unable or unwilling to quit. Long-term health effects of e-vapor products (EVPs) compared with continued smoking have not been extensively studied. We present biomarker of exposure evidence on select harmful and potentially harmful constituents and biomarkers of potential harm related to inflammation and oxidative stress in adult smokers switching to two EVPs. This study demonstrates significant reductions in biomarkers of exposure (except for nicotine) accompanied with favorable changes in various biomarkers of potential harm, including pulmonary function. The totality of evidence suggests that exclusive EVP use may present lower health risks compared with smoking cigarettes.

Pulmonary Health Effects of Electronic Cigarettes: A Scoping Review

BACKGROUND

There is global concern regarding the public health impact of electronic cigarettes (ECs). ECs are commonly promoted as safer than conventional cigarettes (CCs), however there is limited knowledge of the long-term health effects. This scoping review examined the pulmonary health effects of ECs reported in the literature from 2009 to 2019.

METHOD

PubMed, CINAHL, and Science Direct databases were used. Search terms included "vaping, electronic nicotine delivery systems, electronic cigarettes, lung diseases, respiratory diseases, and pulmonary." Original research articles in English that used human subjects between January 1, 2009 and January 31, 2020 and reported pulmonary outcomes were included.

RESULTS

Forty-five studies met the inclusion criteria. There were 14 (31.1%) randomized experimental, 7 (15.6%) nonrandomized experimental, 6 (13.3%) cohort, and 18 (40.0%) cross-sectional studies. Sixteen (35.6%) studies were conducted in the United States; the rest were conducted across 11 other countries. The total number of subjects was 1,465,292 and ages ranged from 12 to 99 years across studies. Eligible studies demonstrated an association between EC use and pulmonary symptoms, asthma and chronic obstructive pulmonary disease diagnosis and exacerbations. The degree of this association varied based on the use of additional tobacco products. EC use resulted in worse outcomes than nonsmoking, but resulted in improved outcomes when compared with CC use or dual use of CC and EC.

CONCLUSION

Evidence indicates that EC use, especially dual use, leads to negative pulmonary effects and adverse outcomes. Education on the potential risks and publishing of EC ingredients on labels could help improve public health safety communication and reduce EC use.

The roles of catechins in regulation of systemic inflammation

Catechins are a phytochemical present in plants such as tea leaves, beans, black grapes, cherries, and cacao, and have various physiological activities. It is reported that catechins have a health improvement effect and ameliorating effect against various diseases. In addition, antioxidant activity, liver damage prevention, cholesterol lowering effect, and anti-obesity activity were confirmed through in vivo animal and clinical studies. Although most diseases are reported as ones mediating various inflammations, the mechanism for improving inflammation remains unclear. Therefore, the current review article evaluates the physiological activity and various pharmacological actions of catechins and conclude by confirming an improvement effect on the inflammatory response.

News events and their relationship with US vape sales: an interrupted time series analysis

OBJECTIVE

News coverage around vaping-related events may have furthered misconceptions regarding the relative harms of vapes. Such information may influence the decisions of individuals who smoke, around switching to vaping, potentially affecting the overall tobacco mortality burden. Thus, it is prudent to study how news events (e.g., 2019 vaping illness epidemic) are associated with vape sales in the United States, to possibly reduce the tobacco mortality burden.

METHODS

We used weekly retail sales data for e-cigarettes (30 December 2018 - 28 December 2019) from the US retail scanner data compiled by the Nielsen Company. We used an interrupted time series design with segmented regression analysis to determine immediate and longer-term impacts of individual news events (e.g. Trump administration's planned ban on some flavored vaping products) on vape sales, controlling for pre-existing trends.

RESULTS

Unexpectedly, we noted a statistically significant positive relationship between vape sales and the CDC announcing an investigation into vaping-related illnesses (Change: 6.59%, Estimate: 0.066; 95% CI: 0.036, 0.092; P < 0.001). We also observed a similar positive association between vape sales and the CDC's announcement on the link between Vitamin E acetate and EVALI (Change: 2.93%, Estimate: 0.029; 95% CI: 0.003, 0.055; P < 0.05). There was a steep decline in sales after these events.

CONCLUSIONS

News events may be associated with US vape sales. Findings have implications for the management of risk perceptions around vaping to improve health outcomes of tobacco users. Information-based policy instruments can be applied to balance the effects of news events that may influence vape sales.

Vaping-Associated Lung Injury: A Review

Since commercial development in 2003, the usage of modern electronic cigarette (e-cigarette) continues to increase amongst people who have never smoked, ex-smokers who have switched to e-cigarettes, and dual-users of both conventional cigarettes and e-cigarettes. With such an increase in use, knowledge of the irritative, toxic and potential carcinogenic effects on the lungs is increasing. This review article will discuss the background of e-cigarettes, vaping devices and explore their popularity. We will further summarise the available literature describing the mechanism of lung injury caused by e-cigarette or vaping use.

Electronic cigarettes as a harm reduction strategy among patients with COPD: protocol for an open-label two arm randomized controlled pilot trial

BACKGROUND

Smoking cessation is the most effective means of slowing the decline of lung function associated with chronic obstructive pulmonary disease (COPD). While effective smoking cessation treatments are available, they are underutilized and nearly half of people with COPD continue to smoke. By addressing both nicotine and behavioral dependence, electronic cigarettes (EC) could help people with COPD reduce the harm of combustible cigarettes (CC) through reductions in number of Cigarettes per Day (CPD) or quitting CC completely. The purpose of this pilot study is to identify barriers and facilitators to the use of and assess the preliminary effectiveness of EC as a harm reduction strategy among people with COPD.

METHODS

In an open-label two-arm randomized controlled trial pilot study, 60 patients identified as smokers with a COPD diagnosis via electronic health records from a large urban health center are randomized in a 1:1 ratio to either standard care [counseling + nicotine replacement therapy (NRT)] or counseling + EC. The NRT arm will receive nicotine patches and nicotine lozenges for 12 weeks. The EC arm will receive EC for 12 weeks. Both cohorts will receive counseling from a licensed mental health counselor. Using ecological momentary assessment, participants will report their use of CC in both arms and EC use in the EC arm daily via text message. Primary outcomes will be feasibility and acceptability of intervention, and secondary outcomes will be reduction in CPD and change in COPD symptoms as measured by COPD Assessment Tool (CAT) score at 12-weeks. EC displacement of CC. To explore attitudes towards the use of EC as a harm-reduction strategy for patients with COPD, interviews will be performed with a sample of participants from both study arms.

DISCUSSION

Despite decades of availability of smoking cessation medications, nearly half of people with COPD still smoke. This study aims to address the unmet need for feasible and effective strategies for reducing CC use among those with COPD, which has the potential to significantly improve the health of people with COPD who smoke. Trial Registration ClinicalTrials.gov Identifier: NCT04465318.

A scoping review of studies on the health impact of electronic nicotine delivery systems

We conducted a scoping review of studies on health outcomes from electronic nicotine delivery systems (ENDS). The objective was to identify, narratively synthesize, assess the strength and quality of evidence and critically appraise studies that have reported disease end points associated with the use of ENDS. We included published literature on the health impact of ENDS from 01/01/2015 until 01/02/2020 following the PRISMA guidelines using PubMed, Embase, Scopus and Google Scholar. The database search identified 755 studies, and other sources 265; 37 studies met final eligibility criteria. Levels of evidence included 24(65%) cross-sectional, one (2.7%) case-control and six (16%) case studies, four (11%) cohort studies, one (2.7%) randomized controlled trial (RCT) and one (2.7%) meta-analysis; 27(73%) studies reported only on harms, eight (22%) reported on benefits, two (2%) on benefits and harms. Quality ratings were poor in 20 (54%), fair in 9(24%) and good in 8(22%) of studies. In our review, ENDS was not shown to be causative for harmful cardiovascular disease (CVD) outcomes and shown to be beneficial for hypertensive patients. Switching from cigarettes to e-cigarettes resulted in reduced exacerbations of chronic obstructive pulmonary disease (COPD), with no evidence of long-term deterioration in lung function. Mental Health, cancer and mortality were not adequately studied to form any consensus. Our review has not demonstrated ENDS to be causative of harmful CVD outcomes; furthermore switching from cigarettes to e-cigarettes was associated with improved hypertensive control and reduced exacerbations of COPD, with no evidence of increased asthma risk or long-term respiratory harm. Mental health, cancer and mortality outcomes have not been adequately studied to form a conclusion. Overall, the findings of our review did not provide evidence to counter the consensus held by many that ENDS use is safer than the risks posed from smoking cigarettes.

Clinical Pharmacology of Electronic Nicotine Delivery Systems (ENDS): Implications for Benefits and Risks in the Promotion of the Combusted Tobacco Endgame

Electronic nicotine delivery systems (ENDS) such as e-cigarettes and heated tobacco products are novel battery-operated devices that deliver nicotine without combustion of tobacco. Because cigarette smoking is sustained by nicotine addiction and the toxic combustion products are mainly responsible for the harmful effects of smoking, ENDS could be used to promote smoking cessation while exposing users to lower levels of toxicants compared with conventional cigarettes. The currently available evidence from clinical and observational studies indicates a potential role of e-cigarettes as smoking cessation aids, although many continue to use e-cigarettes long after quitting smoking. Nicotine and toxicant delivery vary considerably by device and depend on the characteristics of the e-liquid formulation. Because smokers tend to titrate their nicotine intake to maintain their desired pharmacologic effects, device and liquid characteristics need to be considered when using ENDS as an aid to quit smoking. Factors potentially limiting their use are the currently still unknown long-term safety of these products and concerns regarding widespread use among youth. Implications of clinical pharmacology data on ENDS for the cigarette endgame and regulation by the U.S. Food and Drug administration are discussed.

Electronic Cigarette Exposure Enhances Lung Inflammatory and Fibrotic Responses in COPD Mice

Although a few studies show that the use of electronic nicotine delivery systems (ENDS) may ameliorate objective and subjective outcomes in COPD smokers who switched to electronic cigarettes, it is unclear whether e-cigarette exposure alters lung pathological features and inflammatory response in COPD. Here, we employed βENaC-overexpressing mice bearing COPD-like pulmonary abnormality, and exposed them to ENDS. We found that ENDS exposure aggravated airspace enlargement and mucus production in βENaC-overexpressing mice, which was associated with increased MMP12 and Muc5ac, respectively. ENDS exposure to mice significantly increased the numbers of macrophages, particularly in M2 macrophages in bronchoalveolar lavage (BAL) fluid, despite ENDS did not induce M2 macrophage polarization in a cultured murine macrophage cell line (RAW264.7). There were no changes in neutrophils in BAL fluid by ENDS exposure. Multiple cytokine productions were increased including M-CSF, IL-1rα, IL-10, and TGF-β1, in BAL fluid from mice when exposed to ENDS. The Sirius Red staining and hydroxyproline assay showed ENDS-exposed mice displayed enhanced fibrotic phenotypes compared to control mice. In conclusion, ENDS exposure enhances airspace enlargement, mucus secretion, and fibrogenesis in COPD mice. This is associated with increased MMP12, inflammatory responses, and M2 macrophage phenotype. This study provides pre-clinical data implicating that electronic cigarette exposure is not safe in COPD patients who want to replace traditional cigarettes with ENDS.

An updated overview of e-cigarette impact on human health

The electronic cigarette (e-cigarette), for many considered as a safe alternative to conventional cigarettes, has revolutionised the tobacco industry in the last decades. In e-cigarettes, tobacco combustion is replaced by e-liquid heating, leading some manufacturers to propose that e-cigarettes have less harmful respiratory effects than tobacco consumption. Other innovative features such as the adjustment of nicotine content and the choice of pleasant flavours have won over many users. Nevertheless, the safety of e-cigarette consumption and its potential as a smoking cessation method remain controversial due to limited evidence. Moreover, it has been reported that the heating process itself can lead to the formation of new decomposition compounds of questionable toxicity. Numerous in vivo and in vitro studies have been performed to better understand the impact of these new inhalable compounds on human health. Results of toxicological analyses suggest that e-cigarettes can be safer than conventional cigarettes, although harmful effects from short-term e-cigarette use have been described. Worryingly, the potential long-term effects of e-cigarette consumption have been scarcely investigated. In this review, we take stock of the main findings in this field and their consequences for human health including coronavirus disease 2019 (COVID-19).

Health outcomes in COPD smokers using heated tobacco products: a 3-year follow-up

Given that many patients with chronic obstructive pulmonary disease (COPD) smoke despite their symptoms, it is important to understand the long-term health impact of cigarette substitution with heated tobacco products (HTPs). We monitored health parameters for 3 years in COPD patients who substantially attenuated or ceased cigarette consumption after switching to HTPs. Changes in daily cigarette smoking, annualized disease exacerbations, lung function indices, patient-reported outcomes (CAT scores) and 6-minute walk distance (6MWD) from baseline were measured in COPD patients using HTPs at 12, 24 and 36 months. These were compared to a group of age- and sex-matched COPD patients who continued smoking. Complete data sets were available for 38 patients (19 in each group). Subjects using HTPs had a substantial decrease in annualized COPD exacerbations within the group mean (± SD) from 2.1 (± 0.9) at baseline to 1.4 (± 0.8), 1.2 (± 0.8) and 1.3 (± 0.8) at 12-, 24- and 36-month follow-up (p < 0.05 for all visits). In addition, substantial and clinically significant improvements in CAT scores and 6MWD were identified at all three time points in the HTP cohort. No significant changes were observed in COPD patients who continued smoking. This study is the first to describe the long-term health effects of HTP use in COPD patients. Consistent improvements in respiratory symptoms, exercise tolerance, quality of life, and rate of disease exacerbations were observed in patients with COPD who abstained from smoking or substantially reduced their cigarette consumption by switching to HTP use.

Electronic Cigarettes and Their Impact on Allergic Respiratory Diseases: A Work Group Report of the AAAAI Environmental Exposures and Respiratory Health Committee

The explosive rise in popularity of electronic cigarette (e-cig) devices over the past decade has led to controversies over the role of these devices in smoking cessation and harm reduction from combustible cigarette smoking. Increased recognition of potential direct harms of e-cigs, including life-threatening and fatal cases of e-cig and vaping product use-associated lung injury, has emphasized the need to curb use until safety can be established. Of particular concern is the steep rise in e-cig use among teenagers and young adults who have never smoked and among individuals with underlying lung disease, such as asthma. In this report, we describe the different types of e-cig devices available, summarize the available data on the potential health benefits and detriments of e-cig use, and highlight the findings of studies examining e-cigs as smoking cessation tools. Because e-cigs have only gained popularity in the last few years, very few studies have been able to demonstrate an impact of e-cig use on harm reduction related to combustible cigarettes. Moreover, the health effects of e-cigs at a population level must be balanced against the harms of e-cig use, which include nicotine dependence and promoting initiation of cigarette use amongst "never smokers." With respect to smoking cessation, e-cigs appear to serve as switching products that may help individuals reduce or quit cigarette use, but do not address nicotine addiction. Finally, we discuss our recommendations for ways that health care providers can screen and counsel patients on e-cig use. The goal of this report is to provide health care providers with the most recent information on this topic so that they can educate patients on the potential pros and cons of e-cig use.

Clearing the Haze: What Do We Still Need to Learn about Electronic Nicotine Delivery Systems?

Electronic nicotine delivery systems (ENDS; i.e., electronic cigarettes, e-cigarettes, vaping devices, vape pens) were introduced to the U.S. market in 2007 as a potential harm reduction alternative for people who smoked combustible cigarettes. Since that time, ENDS popularity grew very quickly, particularly among individuals who smoke cigarettes. However, young people and never smokers also started using ENDS, cohorts for whom these products were not intended. There are now a broad range of devices and e-liquid constituents. ENDS devices vary considerably in their design and generation of potentially toxic chemicals, with higher power devices likely much more hazardous than lower power devices. This landscape may further change after September 9, 2020, when all ENDS manufacturers are required to submit a premarket tobacco product application to the FDA to obtain authorization for marketing. Research has not kept pace with this rapidly changing technology and important questions remain regarding the relative benefits versus risks of ENDS. In light of these challenges, we propose key ENDS research priorities to address these gaps.

Well-being and harm reduction, the consolidated reality of electronic cigarettes ten years later from this emerging phenomenon: A narrative review

Tobacco use is the greatest threat to public health worldwide, killing more than seven million people annually. This paper, about 10 years after the first review on electronic cigarettes, analyses the evolution that this tool has had in these years. It concludes with comments on the significance of the research and why it constitutes an original contribution. We searched PubMed (National Library of Medicine), and PsycINFO (Ovid) (2006-2020) for studies on e-cigarettes (harms and benefits, e-cigarette use, craving and smoking cessation) and smoking cessation treatment (smoking cessation treatment or varenicline or tobacco cessation or reduction or bupropion or NRT or behavioral treatment or ecigarette) and evidence suggests that they may effective as smoking cessation tool and may be less harmful alternatives to combustible cigarette smoking. Consequently, e-cigarettes could be considered as an applicable instrument for Tobacco Harm Reduction (THR) and smoking cessation.

Use of Electronic Cigarettes and Self-Reported Chronic Obstructive Pulmonary Disease Diagnosis in Adults

INTRODUCTION

Electronic cigarette (e-cigarette) use (vaping) has increased in recent years. Chronic obstructive pulmonary disease (COPD) is the third leading cause of death associated with smoking.

AIMS AND METHODS

Based on 2016 and 2017 Behavioral Risk Factor Surveillance System national survey data on 891 242 adult participants who indicated their smoking and vaping status, the cross-sectional association of vaping with self-reported COPD diagnosis was investigated, using univariable and multivariable weighted logistic regression models.

RESULTS

Compared to never users, while dual users showed the highest association with self-reported COPD diagnosis (adjusted odds ratio [aOR] = 4.39; 95% confidence interval [CI] = 3.98 to 4.85), current vapers who were either ex-smokers or never smoked showed significantly higher association with self-reported COPD diagnosis (aOR = 3.24; 95% CI = 2.78 to 3.78 and aOR = 1.47; 95% CI = 1.01 to 2.12, respectively). Current vapers who were ex-smokers showed higher association with self-reported COPD diagnosis than ex-smokers who do not vape (aOR = 1.27; 95% CI = 1.09 to 1.48). Dual users showed higher association with self-reported COPD diagnosis than current smokers who do not vape (aOR = 1.16; 95% CI = 1.05 to 1.27). Ex-smokers showed significantly less association with self-reported COPD diagnosis (aOR = 0.67; 95% CI = 0.64 to 0.71) than current smokers. Current vapers who were either ex-smokers or never smoked had less association with self-reported COPD diagnosis compared to current smokers, with aOR = 0.85 (95% CI = 0.73 to 0.99) and aOR = 0.39 (95% CI = 0.27 to 0.56).

CONCLUSIONS

Vaping is significantly associated with self-reported COPD diagnosis in adults, even among vapers who never smoked. Whether there is a benefit for COPD of switching from smoking to vaping requires study of the long-term effects of vaping.

IMPLICATIONS

With the increase of e-cigarette use in recent years, the health effects of e-cigarettes need to be investigated. While several studies have examined the association of vaping with respiratory symptoms among adolescents, little is known about the association of vaping with susceptibility to COPD among US adults. Using cross-sectional national survey data in adults, our study showed that vaping was significantly associated with self-reported COPD diagnosis. Although our data did not establish the causal relationship between vaping and self-reported COPD diagnosis, this study raises concerns about the observed association between vaping and self-reported COPD diagnosis.

COPD smokers who switched to e-cigarettes: health outcomes at 5-year follow up

BACKGROUND AND AIMS

The long-term health effects of the use of electronic cigarettes (ECs) in patients with chronic obstructive pulmonary disease (COPD) are largely unexplored. We present findings from a 5-year prospective assessment of respiratory parameters in a cohort of COPD patients who substantially reduced conventional smoking or achieved abstinence by switching to ECs.

METHODS

Patients were evaluated prospectively for their measurements of respiratory exacerbations, spirometric indices, quality of life using the COPD assessment tool (CAT), 6-min walk distance (6MWD), as well as conventional cigarette consumption. Baseline measurements prior to switching to EC use were compared with follow-up visits at 12-, 24-, 48- and 60-months. Age- and sex-matched COPD patients reporting to be regular smokers (not using ECs) were the reference group for the analysis.

RESULTS

Complete data were available from 39 patients. Those in the EC user group achieved a marked decline in cigarette smoking or abstinence. COPD EC users had a significant diminution in COPD exacerbations; with the mean (±SD) exacerbation rate falling from 2.3 (±0.9) at baseline to 1.1 (±1.0) at 5 years (p < 0.001), whereas no significant changes were observed in the control group.Significant and constant improvements in lung function, CAT scores and 6MWD were reported in the EC user group over the 5-year observation period compared with the reference group (p < 0.05).

CONCLUSION

The present study suggests that EC use may ameliorate objective and subjective COPD outcomes, and that the benefits gained appear to persist long term. EC use for abstinence and smoking reduction may ameliorate some of the harm resulting from tobacco smoking in COPD patients.

Tobacco smoking, related harm and motivation to quit smoking in people with schizophrenia spectrum disorders

This narrative review focuses on the topic of tobacco smoking amongst people with schizophrenia spectrum disorders. We searched PubMed, PsycInfo and Scopus databases for schizophrenia spectrum disorders and smoking and included articles about the epidemiology of tobacco smoking in people with schizophrenia spectrum disorders, examining the relationship between smoking and mental health. This narrative review describes that a higher prevalence, frequency and impact of both high nicotine dependence and its harmful effects in patients with schizophrenia spectrum disorders compared with those in the general population. Despite several existent theories, the reasons for high smoking rates, the high dependence on nicotine and severity of nicotine withdrawal symptoms are not fully understood. The main aim of this paper is to inform mental health personnel and particularly clinical and health psychologists about the impact and role of tobacco smoking for smokers with schizophrenia spectrum disorders.

Neurotoxicity of e-cigarettes

It appears that electronic cigarettes (EC) are a less harmful alternative to conventional cigarette (CC) smoking, as they generate substantially lower levels of harmful carcinogens and other toxic compounds. Thus, switching from CC to EC may be beneficial for smokers. However, recent accounts of EC- or vaping-associated lung injury (EVALI) has raised concerns regarding their adverse health effects. Additionally, the increasing popularity of EC among vulnerable populations, such as adolescents and pregnant women, calls for further EC safety evaluation. In this state-of-the-art review, we provide an update on recent findings regarding the neurological effects induced by EC exposure. Moreover, we discuss possible neurotoxic effects of nicotine and numerous other chemicals which are inherent both to e-liquids and EC aerosols. We conclude that in recognizing pertinent issues associated with EC usage, both government and scientific researchers must address this public health issue with utmost urgency.

E-cigarettes and Smoking Cessation in Smokers With Chronic Conditions

INTRODUCTION

Many smokers with chronic medical conditions use e-cigarettes. This study assessed the association between e-cigarette use and subsequent smoking-cessation efforts in adult smokers with and without chronic medical conditions.

METHODS

This was a longitudinal cohort study of adult cigarette smokers using Waves 1 and 2 of the Population Assessment of Tobacco and Health Study (2013-2015), analyzed in 2018‒2019. The exposure was the initiation of e-cigarette use by Wave 2. The outcomes at Wave 2 were: (1) past 12-month attempts to quit, (2) cigarette abstinence, (3) ≥50% reduction in cigarette use, and (4) past 12-month use of evidence-based smoking-cessation treatment.

RESULTS

E-cigarette use initiation was associated with increased odds of attempting to quit smoking at Wave 2 among smokers with any chronic medical condition (AOR=1.92, 95% CI=1.42, 2.59) and without chronic medical conditions (AOR=1.81, 95% CI=1.50, 2.18). E-cigarette use initiation was also significantly associated with Wave 2 smoking abstinence in smokers with (AOR=1.95, 95% CI=1.11, 3.43) and without chronic medical conditions (AOR=1.63, 95% CI=1.17, 2.28).

CONCLUSIONS

At a population level, e-cigarette use by smokers with chronic medical conditions is associated with more quitting activity and smoking abstinence. Future studies are needed to assess e-cigarette safety and efficacy to determine whether they may provide an alternative smoking-cessation or harm-reduction strategy for adults with smoking-sensitive disease who cannot achieve these goals with other methods.

Adult E-Cigarettes Use Associated with a Self-Reported Diagnosis of COPD

The use of electronic cigarettes (e-cigarettes) has increased in the US, but little is known about the effects of these products on lung health. The main purpose of this study was to examine the association between e-cigarette use and a participant's report of being diagnosed with chronic obstructive pulmonary disease (COPD) in a nationally representative sample of adults. Methods: The first wave of the Population Assessment of Tobacco and Health (PATH) survey adult data was used (N = 32,320). Potential confounders between e-cigarette users and non-users were balanced using propensity score matching. Odds ratios (OR) were calculated to examine the association between e-cigarette use and COPD in the propensity-matched sample, the entire sample, different age groups, and in nonsmokers. Replicate weights and balanced repeated replication methods were utilized to account for the complex survey design. Results: Of the 3642 participants who met the criteria for e-cigarette use, 2727 were propensity matched with 2727 non e-cigarette users. In the propensity-matched sample, e-cigarette users were more likely to report being diagnosed with COPD (OR 1.43, 95% confidence interval [CI] 1.12-1.85) than non-e-cigarette users after adjusting for confounders. The result was similar in the entire sample and in the different age subgroups. Among nonsmokers, the odds of reporting a COPD diagnosis were even greater among e-cigarette users (OR 2.94, 95% CI 1.73-4.99) compared to non-e-cigarette users. Conclusion: Our findings demonstrate that e-cigarette use was associated with a reported diagnosis of COPD among adults in the US. Further research is necessary to characterize the nature of this association and on the long-term effects of using e-cigarettes.

Multimodal Smoking Cessation in a Real-Life Setting: Combining Motivational Interviewing With Official Therapy and Reduced Risk Products

BACKGROUND

Tobacco use is a global pandemic, affecting an estimated 1.2 billion people and resulting in substantial health burdens and associated costs.

OBJECTIVES

The aim of this study was to estimate the efficacy of several treatments for smoking cessation in a real-life setting and to evaluate predictors of smoking abstinence.

METHODS

This research was designed with a sample of 593 cases recorded over the period between 2015 and 2016. Six treatment groups were included: (1) bupropion and motivational interviewing (MI); (2) bupropion, nicotine replacement therapy (NRT), and MI; (3) NRT and MI; (4) varenicline and MI; (5) personal vaporizer electronic cigarette and MI; and (6) electronic cigarette, cigarette like "cigalike," and MI.

RESULTS

Results support the efficacy of all treatment groups when used in a real-life setting. The predictors of smoking abstinence were sex, partner smoking status, previous quit attempts, daily consumption, self-efficacy, and level of nicotine dependence.

CONCLUSIONS

The use of different therapeutic strategies in clinical practice, including pharmacotherapy and nonstandard electronic nicotine delivery systems, such as an electronic cigarette, ensures a greater chance of cessation success and the possibility of tailoring interventions according to patients' resources.

How to Think-Not Feel-about Tobacco Harm Reduction

INTRODUCTION

The debate over tobacco harm reduction (THR) has divided the tobacco control community into two camps, one expressing serious reservations about THR whereas the other believes that reduced-risk products like e-cigarettes will disrupt the cigarette market. The often emotional debate would benefit from dispassionate data-based evaluation of evidence.

METHODS

After briefly discussing harm reduction in public health and specifically in tobacco control, this paper identifies major issues concerning e-cigarettes and reviews relevant evidence. Issues include: e-cigarettes' risks compared to cigarette smoking; the effect of vaping on youth smoking; vaping's impact on adult smoking cessation; the net long-term public health implications of vaping; and differences in views on policy issues. The intent is to provide a broad overview of issues and evidence, directing readers to more detailed reviews of specific issues.

FINDINGS

Principal findings include the following: (1) while longitudinal studies suggest that vaping increases never-smoking young people's odds of trying smoking, national survey data indicate that adolescents' 30-day smoking prevalence decreased at an unprecedented rate precisely whereas vaping increased. Use of all other tobacco products also declined. (2) Recent population-level studies add evidence that vaping is increasing adult smoking cessation. (3) Vaping is likely to make a positive contribution to public health.

CONCLUSIONS

THR can be a complement to, not a substitute for, evidenced-based tobacco control interventions. Tobacco control professionals need to focus on objective assessment of and discussion about the potential costs and benefits of THR.

IMPLICATIONS

Participants on both sides of the divisive THR debate need to examine the complicated issues and evidence more objectively. This entails considering both the potential benefits and costs associated with reduced-risk products like e-cigarettes. Furthermore, it requires examining different kinds of evidence when considering specific issues. For example, those concerned by longitudinal study findings that vaping increases students' trial of cigarettes should consider US national survey evidence that youth smoking has decreased at an unprecedented rate. A review of the major issues suggests that the potential of vaping to assist adult smokers to quit outweighs the potential negatives.

Effects of flavoring compounds used in electronic cigarette refill liquids on endothelial and vascular function

Electronic cigarette refill liquids are commercially provided with a wide variety of flavoring agents. A recent study suggested that several common flavors may scavenge nitric oxide (NO) and cause endothelial dysfunction. It was the aim of the present study to investigate the effects of these flavors on NO/cyclic GMP-mediated signaling and vascular relaxation. We tested the flavoring agents for effects on Ca²⁺-induced cGMP accumulation and NO synthase activation in cultured endothelial cells. NO scavenging was studied with NO-activated soluble guanylate cyclase and as NO release from a NO donor, measured with a NO electrode. Blood vessel function was studied with precontracted rat aortic rings in the absence and presence of acetylcholine or a NO donor. Cinnamaldehyde inhibited Ca²⁺-stimulated endothelial cGMP accumulation and NO synthase activation at ≥0.3 mM. Cinnamaldehyde and diacetyl inhibited NO-activated soluble guanylate cyclase with IC₅₀ values of 0.56 (0.54–0.58) and 0.29 (0.24–0.36) mM, respectively, and caused moderate NO scavenging at 1 mM that was not mediated by superoxide anions. The other compounds did not scavenge NO at 1 mM. None of the flavorings interfered with acetylcholine-induced vascular relaxation, but they caused relaxation of pre-contracted aortas. The most potent compounds were eugenol and cinnamaldehyde with EC₅₀ values of ~0.5 mM. Since the flavors did not affect endothelium-dependent vascular relaxation, NO scavenging by cinnamaldehyde and diacetyl does not result in impaired blood vessel function. Although not studied in vivo, the low potency of the compounds renders it unlikely that the observed effects are relevant to humans inhaling flavored vapor from electronic cigarettes.

Electronic Cigarettes: Common Questions and Answers

Electronic cigarettes (e-cigarettes) are popular devices designed to heat a liquid solution, often containing nicotine, that generates an inhaled aerosol, or vapor. e-Cigarettes have been marketed as healthier alternatives to traditional cigarettes. Thus, most adult users are current or former smokers who use e-cigarettes to reduce or quit cigarette smoking. Switching completely from cigarettes to e-cigarettes is associated with reduced toxicant exposure and reduced short-term respiratory symptoms; however, long-term health effects of e-cigarettes are unknown. Although a recent randomized trial suggests that e-cigarettes may promote smoking cessation, systematic reviews have had low certainty of evidence regarding cessation. e-Cigarettes pose several potential health risks, including exposure to heavy metals and toxicants, and nicotine poisoning. e-Cigarettes are also popular among youth, with rates of e-cigarette use surpassing those of cigarette use in this population. Youth e-cigarette use is associated with increased risk of subsequent cigarette and marijuana use. Screening for e-cigarette use in youth and adults, including pregnant women, in conjunction with screening for tobacco use, is advised. Education and interventions to prevent e-cigarette use should be provided to all youth. Youth should be counseled to stop using nicotine/tobacco products, including e-cigarettes. Although the impact of e-cigarette use in pregnancy is unknown, nicotine is a teratogen; thus, pregnant women should be counseled to abstain from using all nicotine/tobacco products.

Immunological and pathological effects of electronic cigarettes

Electronic cigarettes (E-cigarettes) are considered a preferable alternative to conventional cigarettes due to the lack of combustion and the absence of tobacco-specific toxicants. E-cigarettes have rapidly gained in popularity in recent years amongst both existing smokers and previous non-smokers. However, a growing literature demonstrates that E-cigarettes are not as safe as generally believed. Here, we discuss the immunological, and other, deleterious effects of E-cigarettes on a variety of cell types and host defence mechanisms in humans and in murine models. We review not only the effects of complete E-cigarette liquids, but also each of the main components-nicotine, humectants and flavourings. This MiniReview thus highlights the possible role of E-cigarettes in the pathogenesis of disease and raises awareness of the potential harm that E-cigarettes may cause.

Electronic cigarettes: a task force report from the European Respiratory Society

There is a marked increase in the development and use of electronic nicotine delivery systems or electronic cigarettes (ECIGs). This statement covers electronic cigarettes (ECIGs), defined as "electrical devices that generate an aerosol from a liquid" and thus excludes devices that contain tobacco. Database searches identified published articles that were used to summarise the current knowledge on the epidemiology of ECIG use; their ingredients and accompanied health effects; second-hand exposure; use of ECIGs for smoking cessation; behavioural aspects of ECIGs and social impact; in vitro and animal studies; and user perspectives.ECIG aerosol contains potentially toxic chemicals. As compared to conventional cigarettes, these are fewer and generally in lower concentrations. Second-hand exposures to ECIG chemicals may represent a potential risk, especially to vulnerable populations. There is not enough scientific evidence to support ECIGs as an aid to smoking cessation due to a lack of controlled trials, including those that compare ECIGs with licenced stop-smoking treatments. So far, there are conflicting data that use of ECIGs results in a renormalisation of smoking behaviour or for the gateway hypothesis. Experiments in cell cultures and animal studies show that ECIGs can have multiple negative effects. The long-term effects of ECIG use are unknown, and there is therefore no evidence that ECIGs are safer than tobacco in the long term. Based on current knowledge, negative health effects cannot be ruled out.

[COPD and smoking cessation: Patients' expectations and responses of health professionals]

The importance of smoking cessation in the management of COPD is well-established: the benefit of quitting smoking as regards morbidity and mortality outcomes in patients, is unquestioned. The smoking cessation in COPD patients is difficult: high levels of consumption, the duration of smoking, high dependence level, psychological co-morbidities such as anxiety and depression, lower socio-economic and intellectual level, constitute barriers. Studies have shown that patients often minimize the risks of smoking, that others do not believe in the benefits of quitting or doubt their ability to quit smoking. The patients' experience, and expectations with regard to smoking cessation are incompletely satisfied: are considered, the smoking characteristics of these patients, the understanding of the tobacco dependence, the beliefs and ideas of smokers, the knowledge of smoking cessation methods, the role of validated aids and alternative treatments, failure management. The answers of the health professionals can be in several directions: establishment of a better communication patient-doctor (empathy), more centered on the needs of the smoker, the role of the motivation and the place of the motivational interview, the understanding of the mechanisms of addiction, a better individualisation of therapeutics, the necessity of a extended follow-up, the contribution of modern technologies, the electronic cigarette, the smoking cessation in respiratory rehabilitation, guidelines that address smoking cessation treatment.