This cross-sectional study examines e-cigarette use and lung cancer screening uptake among individuals in the US.

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.
CONCLUSIONS: 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.
BACKGROUND: PROSPERO CRD42018099692.

In recent years, electronic cigarettes (e-cigs) have gained popularity as stylish, safe, and effective smoking cessation aids, leading to widespread consumer acceptance. Although previous research has explored the acute effects of combustible cigarettes or nicotine replacement therapy on brain functional activities, studies on e-cigs have been limited. Using fNIRS, we conducted graph theory analysis on the resting-state functional connectivity of 61 male abstinent smokers both before and after vaping e-cigs. And we performed Pearson correlation analysis to investigate the relationship between alterations in network metrics and changes in craving. E-cig use resulted in increased degree centrality, nodal efficiency, and local efficiency within the executive control network (ECN), while causing a decrease in these properties within the default model network (DMN). These alterations were found to be correlated with reductions in craving, indicating a relationship between differing network topologies in the ECN and DMN and decreased craving. These findings suggest that the impact of e-cig usage on network topologies observed in male smokers resembles the effects observed with traditional cigarettes and other forms of nicotine delivery, providing valuable insights into their addictive potential and effectiveness as aids for smoking cessation.

In the past few years, technological advancements enabled the development of novel electronic nicotine delivery systems (ENDS). Several empirical measures such as \"nicotine flux\" are being proposed to evaluate the abuse liability potential of these products. We explored the applicability of nicotine flux for clinical nicotine pharmacokinetics (PK) and 52-week quit success from cigarettes for a wide range of existing nicotine delivery systems. We found that the differences in nicotine flux for various nicotine delivery systems are not related to changes in PK, as nicotine flux does not capture key physiological properties such as nicotine absorption rate. Further, the 52-week quit success and abuse liability potential of nicotine nasal sprays (high nicotine flux product), and nicotine inhalers (nicotine flux similar to ENDS) are low, suggesting that nicotine flux is a poor metric for the assessment of nicotine delivery systems. PK indices are more dependable for characterizing nicotine delivery systems, and a nicotine plasma C max T max > 1 could improve 52-week quit success from cigarettes. However, a single metric may be inadequate to fully assess the abuse liability potential of nicotine delivery systems and needs to be further studied. A combination of in vitro and in silico approaches could potentially address the factors influencing the inhaled aerosol dosimetry and resulting PK of nicotine to provide early insights for ENDS assessments. Further research is required to understand nicotine dosimetry and PK for ad libitum product use, and abuse liability indicators of nicotine delivery systems. This commentary is intended to (1) highlight the need to think beyond a single empirical metric such as nicotine flux, (2) suggest potential PK-based metrics, (3) suggest the use of in vitro and in silico tools to obtain early insights into inhaled aerosol dosimetry for ENDS, and (4) emphasize the importance of considering comprehensive clinical pharmacology outcomes to evaluate nicotine delivery systems.

UNASSIGNED: Chronic obstructive pulmonary disease (COPD) is currently listed as the 3rd leading cause of death in the United States. Accumulating data shows the association between COPD occurrence and the usage of electronic nicotine delivery systems (ENDS) in patients. However, the underlying pathogenesis mechanisms of COPD have not been fully understood.
UNASSIGNED: In the current study, bENaC-overexpressing mice (bENaC mice) were subjected to whole-body ENDS exposure. COPD related features including emphysema, mucus accumulation, inflammation and fibrosis are examined by tissue staining, FACS analysis, cytokine measurement. Cell death and ferroptosis of alveolar epithelial cells were further evaluated by multiple assays including staining, FACS analysis and lipidomics.
UNASSIGNED: ENDS-exposed mice displayed enhanced emphysema and mucus accumulation, suggesting that ENDS exposure promotes COPD features. ENDS exposure also increased immune cell number infiltration in bronchoalveolar lavage and levels of multiple COPD-related cytokines in the lungs, including CCL2, IL-4, IL-13, IL-10, M-CSF, and TNF-α. Moreover, we observed increased fibrosis in ENDS-exposed mice, as evidenced by elevated collagen deposition and a-SMA+ myofibroblast accumulation. By investigating possible mechanisms for how ENDS promoted COPD, we demonstrated that ENDS exposure induced cell death of alveolar epithelial cells, evidenced by TUNEL staining and Annexin V/PI FACS analysis. Furthermore, we identified that ENDS exposure caused lipid dysregulations, including TAGs (9 species) and phospholipids (34 species). As most of these lipid species are highly associated with ferroptosis, we confirmed ENDS also enhanced ferroptosis marker CD71 in both type I and type II alveolar epithelial cells.
UNASSIGNED: Overall, our data revealed that ENDS exposure exacerbates features of COPD in bENaC mice including emphysema, mucus accumulation, abnormal lung inflammation, and fibrosis, which involves the effect of COPD development by inducing ferroptosis in the lung.

OBJECTIVE: To measure changes over time (between 2017 and 2023) in disposable e-cigarette use and popular brands among youth in Canada, England and the United States (US) who vaped.
METHODS: Nine waves of repeat cross-sectional data from the International Tobacco Control Policy Evaluation Project (ITC) Youth Tobacco and Vaping Survey.
METHODS: Online surveys conducted in Canada, England and the US between 2017 and 2023.
METHODS: Youth aged 16 to 19 years who had vaped in the past 30 days (n = 19 710).
METHODS: Usual type (disposable, cartridge/pod, tank) and brand of e-cigarette used; covariates sex at birth, age, race/ethnicity, cigarette smoking status, vaping on ≥20 of the past 30 days.
RESULTS: In 2017, the majority of youth who vaped in the past 30 days reported using refillable tank e-cigarettes, whereas disposable e-cigarettes were the least commonly used product type in Canada (10.0%), England (8.6%) and the US (14.4%). Cartridge/pods overtook tank devices in Canada and the US by 2020; however, by 2023, disposables were the leading type of e-cigarette used by youth who vaped in all three countries (Canada = 58.5%; England = 83.2%; US = 67.3%). The shift to disposables occurred among all socio-demographic groups, with few differences by vaping and smoking status. The percentage of youth who vaped that reported \'no usual\' brand also decreased substantially from 2017 (29% to 42%) to 2023 (11% to 17%). The rise of disposable e-cigarettes appeared to be driven primarily by individual brands in the US (Puff Bar in 2020/2021, Elf Bar in 2022/2023) and England (Elf Bar in 2022/2023).
CONCLUSIONS: The e-cigarette market has evolved rapidly with notable shifts in the types of e-cigarettes used by youth who vape in Canada, England and the United States. Although the timing differed across countries, major shifts in device types appear to be driven by individual brands and were often accompanied by increases in vaping prevalence among youth.

Evidence from in vitro and animal models has identified the pulmonary toxicity of flavors in electronic cigarettes (ECIGs); however, less is known from epidemiological studies about the effects of flavors in the respiratory health. This study examined the longitudinal association between exposure to ECIGs flavors and nocturnal dry cough among ECIGs users. A secondary analysis of data from the Population Assessment of Tobacco and Health Study (2014-2019) was conducted. The study population included adults who provided information (n = 18,925) for a total of 38,638 observations. Weighted-incidence estimates and weighted- generalized estimating equation models were performed to assess unadjusted and adjusted associations. The weighted incidence proportion (WIP) of nocturnal dry cough was significantly higher among current (WIP:16.6%; 95%CI 10.5, 21.2) and former fruit flavored ECIGs users (WIP:16.6%; 95%CI 11.3, 21.9) as compared to non-ECIGs users (WIP:11.1%; 95%CI 10.6, 11.6). Current ECIGs users of fruit flavors showed 40% higher risk of reporting cough than non-ECIGs users (aRR:1.40, 95%CI 1.01, 1.94). Former ECIGs users of multiple flavors and other flavors had 300% and 66% higher risk to develop cough, respectively (aRR:3.33, 95%CI 1.51, 7.34 and aRR:1.66, 95%CI 1.0.9, 2.51), relative to non-ECIGs users. We observed a significantly higher risk of developing nocturnal dry cough in the past 12 months in current and former ECIGs users of fruit flavors and in former ECIGs users of multiple flavors. To the extent that cough may serve as an early indicator of respiratory inflammation and potential disease risk, the association between ECIGs use and cough raises potential concerns.

The emerging concern about chemicals in electronic cigarettes, even those without nicotine, demands the development of advanced criteria for their exposure and risk assessment. This study aims to highlight the sensitivity of lung nuclear receptors (NRs) to electronic cigarette e-liquids, independent of nicotine presence, and the influence of the sex variable on these effects. Adult male and female C57BL/6J mice were exposed to electronic cigarettes with 0%, 3%, and 6% nicotine daily (70 mL, 3.3 s, 1 puff per min/30 min) for 14 days, using the inExpose full body chamber (SCIREQ). Following exposure, lung tissues were harvested, and RNA extracted. The expression of 84 NRs was determined using the RT2 profiler mRNA array (Qiagen). Results exhibit a high sensitivity to e-liquid exposure irrespective of the presence of nicotine, with differential expression of NRs, including one (females) and twenty-four (males) in 0% nicotine groups compared to non-exposed control mice. However, nicotine-dependent results were also significant with seven NRs (females), fifty-three NRs (males) in 3% and twenty-three NRs (female) twenty-nine NRs (male) in 6% nicotine groups, compared to 0% nicotine mice. Sex-specific changes were significant, but sex-related differences were not observed. The study provides a strong rationale for further investigation.

Despite interest in quitting vaping among young adults (YAs), little is known about characteristics of e-cigarette (EC) users seeking treatment. In this study, YAs aged 18-24 living in the United States interested in vaping cessation treatment were recruited to complete an online survey regarding demographics and EC use. Primary eligibility criteria were EC use on at least 20 days per month (no other tobacco use), and interest in quitting in the next month. We report descriptive statistics for those who did and did not complete a mandatory coaching call (n = 981). In this sample, most EC users reported high nicotine dependence, a history of unsuccessful quit attempts (including 29.4% with previous NRT use), along with stress, anxiety, and depression. There were few meaningful differences in demographics, EC use behaviors, or behavioral health factors between those who engaged with a phone coaching call (fully enrolled in study; n = 508), and those who did not (n = 473). YAs demonstrated interest in vaping cessation support, but there were no clear characteristics for the half who did not complete a coaching call. Vaping cessation program designers should consider tailoring for the self-reported behavioral health concerns present in this population.

OBJECTIVE: The primary objective of this in vitro experiment was an assessment of proliferative capacity, metabolic activity, and potential cellular detriment of human periodontal ligament cells (hPDL) exposed to cigarette smoke (CS), electronic cigarette vapor (eCV), and heated tobacco product aerosol (HTP), or air (control).
METHODS: Using a CAD/CAM-designed exposition chamber, hPDL were exposed to CS, eCV, HTP, or air (control) based on the Health Canada Intense Smoking Regime. Cell proliferation, metabolic activity, and cellular detriment were assessed at various time points.
RESULTS: Compared to the control, hPDL exposed to CS exhibited significantly decreased cell numbers at all time points. HTP exposure led to reduced cell numbers 48 h and 72 h post-exposure, while eCV-exposed cells showed no significant decrease. The metabolic activity of eCV-treated hPDL was slightly reduced at 7 h but recovered at 24 h and 48 h. In contrast, CS-treated cells exhibited significantly decreased metabolic activity at 24 h and 48 h, and HTP-exposed cells showed a significant decrease after 48 h. Flow cytometry indicated both apoptotic and necrotic cell death following CS exposure, with necrotic cell death being more pronounced.
CONCLUSIONS: eCV and HTP demonstrated comparatively reduced detrimental effects on hPDL compared to CS.
CONCLUSIONS: The findings suggest that conventional cigarette smoke poses a substantial risk to periodontal health by significantly impairing cell proliferation and metabolic activity. However, alternatives such as eCV and HTP may offer a comparatively reduced risk.