Combustible Cigarette Smoking Research Articles

Effects of short-term nicotine deprivation on delay discounting among young, experienced, exclusive ENDS users: An initial study.

Delay discounting describes how rapidly delayed rewards lose value as a function of delay and serves as one measure of impulsive decision-making. Nicotine deprivation among combustible cigarette smokers can increase delay discounting. We aimed to explore changes in discounting following nicotine deprivation among electronic nicotine delivery systems (ENDS) users. Thirty young adults (aged 18-24 years) that exclusively used ENDS participated in two laboratory sessions: one with vaping as usual and another after 16 hr of nicotine deprivation (biochemically assessed). At each session, participants completed a craving measure and three hypothetical delay discounting tasks presenting choices between small, immediate rewards and large, delayed ones (money-money; e-liquid-e-liquid; e-liquid-money). Craving for ENDS significantly increased during short-term nicotine deprivation relative to normal vaping. Delay discounting rates in the e-liquid now versus money later task increased (indicating a shift in preference for smaller, immediate rewards) following short-term nicotine deprivation relative to vaping as usual, but no changes were observed in the other two discounting tasks. Short-term nicotine deprivation increased the preference for smaller amounts of e-liquid delivered immediately over larger, monetary awards available after a delay in this first study of its kind. As similar preference shifts for drug now versus money later have been shown to be indicative of increased desire to use drug as well as relapse risk, the findings support the utility of the current model as a platform to explore interventions that can mitigate these preference shifts. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Role of Perceived Neighborhood Cohesion in the Association between Depressive Symptoms and Cigarette Smoking

Background Greater depression has been linked to increased smoking rates. However, the mechanisms underlying this association are not fully understood. It is possible that high perceived neighborhood cohesion may serve as one such mechanism given its associations with decreased depression and smoking. Having increased levels of depression likely impacts one’s perceptions of neighborhood cohesion, which could lead to further increases in depression and a need to manage these symptoms via cigarette smoking. As a first test of this theory, the current study examined the effect of neighborhood cohesion on the association between depressive symptoms and smoking frequency and quantity among past 30-day cigarette smokers. Methods Participants were 201 combustible cigarette smokers (Mage = 48.33, SD = 11.64; 63.2% female; 68.2% White) who completed self-report measures as part of a larger study of environmental influences on cardiac health. Results Greater depressive symptoms were associated with lower levels of perceived neighborhood cohesion, and there was a significant indirect effect of greater depressive symptoms on heavier smoking through decreased neighborhood cohesion (b = .07, SE = .04, 95% CI [.003, .15]). There was no significant indirect effect for daily smoking. Conclusion These results suggest that neighborhood cohesion is an important contextual factor that serves as one explanatory mechanism for the well-established relationship between depression and smoking quantity. Thus, there may be utility in implementing interventions focused on increasing neighborhood cohesion as a way to decrease smoking behavior.

Social, educational, and psychological health correlates of e-cigarette and combustible cigarette use among adolescents in the US from 2015 to 2021

BackgroundThe prevalence of e-cigarette and vaping products has increased in the past decade, especially among adolescents. To provide data that will inform identification of youth at high risk, the goals of this study are to determine the social, educational, and psychological health outcomes associated with e-cigarette use distinct from combustible cigarettes. MethodsAnnual samples of adolescents in grade 12 (years: 2015–2021, N = 24,015) were analyzed from Monitoring the Future cross-sectional data. Students were categorized based on vaping and smoking patterns (no use, vape only, combustible cigarette smoking only, or both). Survey-weighted prevalence and logistic regression were used to assess associations. ResultsBetween 2015 and 2021, 78.7% of students used neither e-cigarettes nor combustible cigarettes, 13.2% used e-cigarettes only (vape-only), 3.7% used combustible cigarettes only (smoke-only), and 4.4% used both. Students who vaped-only (OR:1.49, CI:1.28–1.74), smoked-only (OR:2.50, CI:1.98–3.16), or both (OR:3.03, CI:2.43–3.76) had worse academic performance than non-smoking, non-vaping peers after demographic adjustment. There was no significant difference in self-esteem between the “neither” group and the other groups, though the “vaping-only”, “smoking-only” and “both” groups were more likely to report unhappiness. Inconsistent differences emerged regarding personal & family beliefs. ConclusionsGenerally, adolescents who reported e-cigarette-only use had better outcomes than their peers who smoked cigarettes. However, students who vape-only reported poorer academic performance compared to those who did not vape or smoke. Vaping and smoking were not significantly related to self-esteem, but were linked to unhappiness. Still, vaping does not follow the same patterns as smoking, despite frequent comparisons in the literature.

Changes in E-Cigarette Use Among U.S. Adults, 2019–2021

E-cigarette use increased between 2014 and 2018 among younger U.S. adults who had never smoked combustible cigarettes, potentially increasing nicotine addiction risk and progression to combustible tobacco products. It is unknown how prevalence changed after the E-cigarette, or vaping, product use-associated lung injury epidemic (late 2019) and COVID-19 pandemic (March 2020) by age group and combustible cigarette smoking status. Data from cross-sectional, nationally representative National Health Interview Surveys in 2019, 2020, and 2021 (analyzed in 2022) were used to estimate current E-cigarette use prevalence, adjusted prevalence difference between survey years, and population counts, by age group (younger, 18-29 years, n=11,700; middle age, 30-44 years, n=21,300, 45-59 years, n=21,308; older, ≥60 years, n=36,224) and cigarette smoking status (current, former, and never). E-cigarette use prevalence increased among younger adults between 2019 and 2021 (8.8%-10.2%, adjusted prevalence difference=1.7% points, 95% CI=0.1, 3.3), primarily owing to an increase among those who never smoked cigarettes (4.9%-6.4%, adjusted prevalence difference=1.7% points, 95% CI=0.3, 3.1). People who never smoked cigarettes constituted 53% (2.68 million) of younger adults who used E-cigarettes in 2021, increasing by 0.71 million from 2019. Conversely, among middle age and older adults, the prevalence was similar in 2019 and 2021 irrespective of cigarette smoking status, and those who formerly smoked cigarettes constituted the largest proportion of people who used E-cigarettes in 2021 (age 30-44 years: 51.8%, 1.8 million; age 45-59 years: 51.6%, 0.85 million; age ≥60 years: 47.5%, 0.45 million). Efforts must address the rise in E-cigarette use among younger adults who never smoked cigarettes. At the same time, assistance is needed to help those who switched to E-cigarettes to stop smoking to transition to non-use of all products.

Plasma protein binding and tissue retention kinetics influence the rate and extent of nicotine delivery to the brain

Nicotine from inhaled combustible cigarette smoke is delivered rapidly to the brain, and sufficient unbound nicotine concentrations exert pharmacological effects. In addition to nicotine, combustible cigarette smoke also contains a significant number of toxicants that trigger perturbations, leading to an altered steady state due to differential expression of proteins. In this study, a physiologically based pharmacokinetic (PBPK) model for inhaled nicotine was used to simulate the influence of lysosomal change-driven tissue retention and plasma protein binding levels on nicotine pharmacokinetics (PK). A 3 × increase in tissue lysosomal volumes lowered the nicotine brain maximum concentration (Cmax) by 20.8%. Similarly, a 50% increase in plasma protein binding also lowered the unbound plasma arterial nicotine Cmax by 39.4%. Such fundamental changes in nicotine disposition due to physiological changes in combustible cigarette smokers will lead to altered nicotine consumption and exposure-responses of other weakly basic drugs. Literature reports indicate that nicotine consumed from non-combustible products do not alter drug exposures, indicating fewer or less severe toxicant-driven perturbations with the use of these products. Although several other parameters influence nicotine PK, this PBPK modeling study shows that increased tissue retention and plasma protein binding reduce nicotine delivery to the brain and could lead to differential consumption of combustible cigarettes. These differences in physiological states among combustible cigarette smokers need to be evaluated and should be considered during therapeutic interventions.

Smoking is associated with elevated blood level of volatile organic compounds: a population-based analysis of NHANES 2017–2018

BackgroundThe study aims to explore the association between cigarette smoking with blood exposure to volatile organic compounds using population data from the National Health and Nutrition Examination Survey (NHANES) 2017–2018.MethodsBased on the data of NHANES 2017–2018, we identified 1117 participants aged 18 to 65 years, who had complete VOCs testing data and filled out the Smoking-Cigarette Use and Volatile Toxicant questionnaires. The participants consisted of 214 dual-smoking persons, 41 E-cigarette smokers, 293 combustible-cigarette smokers and 569 non-smokers. We used One-way ANOVA and Welch’s ANOVA to compare differences of VOCs concentration among 4 groups and multivariable regression model to confirm the factors associated with VOCs concentration.ResultsIn dual-smoking and combustible-cigarette smokers, blood concentration of 2,5-Dimethylfuran, Benzene, Benzonitrile, Furan, Isobutyronitrile were higher than non-smokers. When compared with people who never smoked, E-cigarette smokers had similar blood concentrations of VOCs. Blood concentrations of Benzene, Furan, and Isobutyronitrile were significant higher in combustible-cigarette smokers than in E-cigarette smokers. In the multivariable regression model, dual-smoking and combustible-cigarette smoking were associated with elevated blood concentrations of several VOCs except 1,4-Dichlorobenzene, while E-cigarette smoking was only associated with elevated 2,5-Dimethylfuran concentration.ConclusionsSmoking, mainly dual-smoking and combustible-cigarette smoking, is associated with elevated blood concentration of VOCs, while the effect is weak in E-cigarette smoking.

Qualitative exploration of longer versus shorter quit attempts among adults using E-Cigarettes for combustible cigarette cessation

Empirical evidence about the effectiveness of using e-cigarettes to quit smoking cigarettes remains inconclusive, yet e-cigarettes are commonly used for smoking cessation. Moreover, people who have longer duration quit attempts are likely to have even longer quit attempts in the future. Researchers analyzed 40 qualitative interviews to assess adults’ experiences using e-cigarettes during their longest duration quit attempt. Interviewees quit smoking for ≥ one month (n = 20) or for shorter durations (n = 20). Thematic and comparative content analyses were used to analyze interview transcripts for factors facilitating or impeding the duration of quit attempts when using e-cigarettes. Participant narratives were mostly similar irrespective of their quit attempt duration. Six themes common across groups as well as themes more often discussed by people with shorter quit attempts are described. Most participants discussed using e-cigarette devices and flavors to either replace sensations similar to smoking combustible cigarettes (e.g., inhaling from a cylindrical object) or to distract themselves from cravings to smoke. E-cigarettes also were described by the majority of participants as useful for smoking cessation because they approximate combustible cigarette use, potentially reduce health-related harms, save money, and lead to reduced social stigma compared to smoking cigarettes. Those who reported shorter duration quit attempts shared e-cigarette product challenges, health concerns, needs for support. Study findings demonstrate the need for additional research on the factors that may increase the likelihood that using e-cigarettes will result in longer and sustained e-cigarette-based quit attempts among adults.

The Substitution of Fifty Percent of Combustible Tobacco Smoke Exposure With Either Electronic Cigarettes or Heated tobacco Products Did Not Attenuate Acute Lung Injury in an Animal Model.

To reduce the harmful health effects of combustible cigarette smoke (CS), some (CS) users attempt to substitute CS with electronic cigarettes (ECIG) and/or heated tobacco products (HTP). In this animal study, we evaluated the acute effects of substituting CS consumption with ECIG or HTP thus mimicking the dual users' approach, on the lungs of a mouse model. C57BL/6 mice were divided into Control, ECIG, HTP, CS, ECIG + CS, HTP + CS, and HTP + ECIG groups. Animals were exposed for 3 hours in AM and PM sessions to either air, CS, ECIG, or HTP for seven days. Lung injury was assessed by: wet to dry (W/D) ratio, albumin concentration in bronchoalveolar lavage fluid, expression of IL-1β, IL-6, and TNF-α, histopathology examination, reactive oxygen species (ROS) production, and assessment of cellular apoptosis. W/D ratio was significantly increased in mice exposed to CS only. Albumin leak and expression of IL-1β, IL-6, and TNF-a were elevated in CS, ECIG + CS, and HTP + CS. Histological examination revealed significant inflammatory cells infiltration, as well as collagen deposit in CS, ECIG + CS, HTP + CS. ROS production was significantly increased in CS, ECIG + CS, HTP + CS. Finally, cell death was also significantly increased in CS, ECIG + CS, and HTP + CS. In this animal model, substituting 50% of daily CS exposure by either ECIG or HTP exposure did not result in significant attenuation of acute lung injury.

Electronic Cigarette Use during Pregnancy: Is It Harmful?

Although combustible cigarette smoking rates have declined in recent years, alternative tobacco product use, particularly electronic cigarette use ("vaping"), has increased among young adults. Recent studies indicate that vaping during pregnancy is on the rise, possibly due to the perception that it is a safer alternative to combustible cigarette smoking. However, e-cigarette aerosols may contain several newer, potentially toxic compounds, including some known developmental toxicants that may adversely impact both the mother and the fetus. However, there is paucity of studies that have examined the effects of vaping during pregnancy. While the adverse perinatal outcomes of cigarette smoking during pregnancy are well established, the specific risks associated with inhaling vaping aerosols during pregnancy requires more research. In this article, we discuss the existing evidence and knowledge gaps on the risks of vaping during pregnancy. Studies that investigate vaping-associated systemic exposure and its effects (i.e., biomarker analyses) and maternal and neonatal clinical health outcomes are needed to reach more robust conclusions. We particularly emphasize the need to go beyond comparative studies with cigarettes, and advocate for research that objectively evaluates the safety of e-cigarettes and other alternative tobacco products.

Study protocol for approach bias retraining for nicotine addiction among dual combustible and electronic cigarette users

BackgroundElectronic cigarette (ECIG) use has become a popular method for nicotine delivery. Combustible cigarette (CC) cessation or reduction are the primary reasons for ECIG uptake among adults. Yet, most CC smokers who initiate ECIG use do not fully transition from CC to ECIG, despite intending to quit CC completely. Retraining approach bias, or the approach action tendency toward stimuli related to the substance of interest, has been effective in alcohol and CC use treatments. However, approach bias retraining for both CC and (ECIG) users has not been explored. Therefore, the objective of the study is to evaluate the initial efficacy of approach bias retraining among dual CC and ECIG users. MethodsEligible dual CC/ECIG using adults (N = 90) will complete a phone-screener, baseline assessment, 4 treatment sessions over 2 weeks, ecological momentary assessments (EMAs) post-intervention, and follow-ups at 4- and 6-week post-intervention. Participants will be assigned to one of three conditions at baseline: (1) CC + ECIG retraining; (2) CC only retraining; and (3) sham retraining. Participants will engage in a self-guided quit attempt to abstain from all nicotine products starting at treatment session 4. ConclusionsThe study may lead to a more effective treatment for at-risk nicotine users while simultaneously isolating explanatory mechanisms. The findings should guide advances in the theoretical conceptualization of nicotine addiction for dual users and mechanisms involved in maintaining and abstaining from CC and ECIG, and provide initial effect size data for a brief intervention, thus providing necessary data for a large-scale follow-up trial.Clinical Trials ID: NCT05306158

Twenty-eight day repeated exposure of human 3D bronchial epithelial model to heated tobacco aerosols indicates decreased toxicological responses compared to cigarette smoke.

Tobacco harm reduction (THR) involves providing adult smokers with potentially reduced harm modes of nicotine delivery as alternatives to smoking combustible cigarettes. Heated tobacco products (HTPs) form a category with THR potential due to their ability to deliver nicotine and flavours through heating, not burning, tobacco. By eliminating burning, heated tobacco does not produce smoke but an aerosol which contains fewer and lower levels of harmful chemicals compared to cigarette smoke. In this study we assessed the in vitro toxicological profiles of two prototype HTPs' aerosols compared to the 1R6F reference cigarette using the 3D human (bronchial) MucilAir™ model. To increase consumer relevance, whole aerosol/smoke exposures were delivered repeatedly across a 28day period (16, 32, or 48 puffs per exposure). Cytotoxicity (LDH secretion), histology (Alcian Blue/H&E; Muc5AC; FoxJ1 staining), cilia active area and beat frequency and inflammatory marker (IL-6; IL-8; MMP-1; MMP-3; MMP-9; TNFα) levels were assessed. Diluted 1R6F smoke consistently induced greater and earlier effects compared to the prototype HTP aerosols across the endpoints, and in a puff dependent manner. Although some significant changes across the endpoints were induced by exposure to the HTPs, these were substantially less pronounced and less frequently observed, with apparent adaptive responses occurring over the experimental period. Furthermore, these differences between the two product categories were observed at a greater dilution (and generally lower nicotine delivery range) for 1R6F (1R6F smoke diluted 1/14, HTP aerosols diluted 1/2, with air). Overall, the findings demonstrate the THR potential of the prototype HTPs through demonstrated substantial reductions in toxicological outcomes in in vitro 3D human lung models.

Association between pain and e-cigarette use stratified by cigarette smoking status: Results from National Health Interview Survey (NHIS) 2019–2020

IntroductionPrevious studies have shown frequent co-morbidities between pain and tobacco use. However, the investigation in use of e-cigarettes, a relatively new tobacco product, at the intersection of pain and cigarette smoking is still lacking. This study used a US national dataset to examine associations between pain experience (pain lasting 3 months) and e-cigarette use, stratified by cigarette smoking status. MethodsThis study used a pooled dataset of the 2019 and 2020 National Health Interview Survey (NHIS) (N = 63,565). We estimated multivariable binomial logistic regressions predicting current e-cigarette use by pain experience, after controlling for survey year, age, sex, race/ethnicity, sexual orientation, education level, health insurance status, other tobacco use, diagnosis of anxiety and depression, use of pain management methods (e.g., physical therapy, behavioral therapy), and prescribed opioid pain reliever use among the overall population, and stratified by cigarette smoking status – never, former, and current cigarette smoking. ResultsAfter controlling for covariates, past-3-month pain experience was associated with current e-cigarette use (aOR = 1.26; 95 % CI = 1.08, 1.46) in the overall population. When stratified by current cigarette smoking, pain experience was associated with current e-cigarette use among current combustible cigarette smokers (aOR = 1.62, 95 % CI = 1.20, 2.18). However, there was no significant difference in e-cigarette use by pain experience among non-current cigarette smokers (p = 0.103). ConclusionsWe observed a higher likelihood of e-cigarette use among US adults experiencing pain. Future studies are needed to investigate mechanisms linking pain and e-cigarette use to inform smoking/vaping prevention and cessation interventions.

The spread of heated tobacco product (HTP) use across various subgroups during 2015–16 and 2017–18 in Japan

Heated tobacco product (HTP) use has increased substantially between 2016 and 2017 in Japan. This study aims to clarify how HTP use (IQOS, Ploom, and glo) spread across the different combustible cigarette smoking statuses during 2015-16 and 2017-18 in Japan. We compared the two periods of (i) 2015 to 2016 (N = 5,366) and (ii) 2017 to 2018 (N = 3,422) from a longitudinal study randomly sampling members from the Japan "Society and New Tobacco" Internet Survey (JASTIS). Multivariable logistic regression models for current HTP use in the previous 30 days by combustible cigarette smoking status in the previous year were used adjusting for socio-demographic factors. HTP use increased by 10 times in the 2017-18 cohort compared with the 2015-16 cohort according to the adjusted odds ratio (95% confidence interval) for current HTP use as 10.2 (7.03-14.8). According to smoking status, significantly higher adjusted ORs (95% CIs) of current HTP use for the after period were observed: 2.60 (1.37-4.94) for never smokers, 7.82 (3.64-16.8) for former smokers, 21.1 (5.73-77.9) for current smokers with intention to quit, and 17.0 (9.58-30.3) for current smokers without intention to quit. During 2015 to 2018 in Japan, HTP use dramatically increased in all subgroups except for never smokers.

Functional Benefit of Smoking Cessation and Triple Inhaler in Combustible Cigarette Smokers with Severe COPD: A Retrospective Study.

Introduction: Chronic obstructive pulmonary disease (COPD) is the third cause of mortality and it is smoking-related. It is characterized by a non-reversible airflow limitation and a progressive worsening of the respiratory function. Objective: The aim of this study is to point out the benefit of smoking cessation combined with a single inhaler triple therapy in terms of clinical and functional outcome in this setting. Methods: A retrospective analysis was performed in patients affected by severe COPD and at least one exacerbation a year, who underwent a smoking cessation program. All patients underwent a 6 min walking test, body plethysmography, and an exhaled test for carbon monoxide. The modified medical research council test (mMRC) test, the Fagestrom nicotine dependency test (FTND) and the COPD assessment test (CAT) questionnaire were also administered. All patients were checked at the baseline and in the six-month follow-up after the start of the treatment. Results: Smoking cessation was achieved by 51% of patients within a month and it was confirmed by eCO measure (<7 ppm). Patients who quit smoking reported better results after six months compared with patients who did not. The increase in FEV1 within the group of quitters was 90 mL (p < 0.05) and the walking test improved by 90 m (p < 0.01); eCO decreased by 15 ppm (p < 0.01) while FVC increased by 70 mL (p < 0.05). No significant changes were recorded within the group of sustainers. The difference in functional changes between groups was significant with regard to FEV1, cCO, and WT. Conclusions: Smoking cessation enhances the efficacy of single inhaler triple therapy, improving clinical and functional variables after six months from the start.

Cytotoxicity and cell injuries of flavored electronic cigarette aerosol and mainstream cigarette smoke: A comprehensive in vitro evaluation

IntroductionAlthough electronic cigarettes (e-cigarettes) have attracted much attention due to their claimed harm-reduction effects compared with conventional cigarettes, the adverse effects of e-cigarette aerosol exposure on human health are still unclear. In this work we compared the cytotoxic effects of combustion cigarettes with four commercially available flavored electronic cigarettes and their main components on ten cell lines. Cell injury mechanism of e-cigarette aerosol and combustible cigarette smoke was also explored using cellular models. MethodsEleven kinds of e-cigarettes aerosol condensates (ECSCs) and cigarette smoke constituent’s condensates (CSC) were collected by Cambridge filter pad, and the nicotine contents were determined by UPLC to provide an equivalent nicotine dosage. The CCK-8 assay was used to measure the cell viability differences between ECSC and CSC. Based on RNA-seq results, we compared the effects of ECSC and CSC on various cell injury pathways. Oxidative stress and inflammatory responses were further tested by Western Blot, immunofluorescence, and qRT-PCR assays. ResultsCSC was found to be more cytotoxic than flavored ECSC and their main components, and BEAS-2B cell line was the most sensitive cells by comparing the IC50 value. With prolonged exposure duration and higher doses, ECSC began to exhibit cytotoxicity at and above 72 µg/mL. The IC50 values of ECSC were 15-fold higher than that of CSC. Transcriptome analyses indicated that cell injury-related processes were enriched after the treatment of CSC. CSC could significantly induce more oxidative stress and inflammatory signals than ECSC. ConclusionECSCs and their components induced significantly less cytotoxicity than CSC under the laboratory exposure conditions, and CSC caused much severe cell injuries. Our study adds to the body of scientific evidence for a more comprehensive safety evaluation of e-cigarette products as compared to cigarettes.

Health Behaviors in Combustible Cigarette, Heated Tobacco Users and Quitters

Smoking can be changed by health behavior education on the fact that unhealthy behaviors can cause chronic diseases and cancer and that it is important to identify health behaviors in smoking. We try to compare the health behaviors of combustible cigarette (CC), heated tobacco (HT) users, and quitters. Smoking behaviors were divided into three groups (CC, HT users, and quitters). The HT user group (n = 100) was selected among those who underwent a health examination in 2021-2022. CC smokers cohort group (n = 100) and quitters cohort (n = 100) were randomly selected from the same groups (age ± 2) who underwent a health examination in the same period. Sleep-related problems (snoring and sleep apnea), alcohol consumption, and exercise were compared in the CC group, HT group, and quitters group, respectively. Snoring was more common in the quitters group (27%) than in the CC users group (19%) and HT users group (18%). It can be related to weight gain during quitting tobacco use. Nondrinkers were more common in the CC users group (21%) than the HT users group (8%) and quitters group (10%). CC users seem to be more concerned about the health effects of drinking compared to HT users and quitters. Anaerobic exercise was different among groups, and aerobic exercise was not. HT users group did more aerobic exercise than CC users and quitters group. Differences in healthy behaviors among CC and HC users and quitters can be useful information for health education to smokers. Understanding smokers’ health behavior is important to smoking cessation counseling in clinical practice.

Exposure to Heated Tobacco Products Aerosol Causes Acute Stress Responses in the Lung of Mouse.

In the present study, we evaluated the acute response of mice exposed to IQOS aerosol, a brand-name heated tobacco product (HTP), in the lung tissue. First, the thiobarbituric acid-reactive substances (TBA-RS) value was measured as an index to assess oxidative stress, and a significant increase was observed after exposure, followed by a significant increase in the total lung GSH concentration. The stress responses induced by IQOS aerosols was then analyzed by focusing on the changes in Nrf2 and ATF4, which are transcription factors that induce the expression of genes involved in GSH biosynthesis or metabolism. Although Nrf2 activation was not observed, significant accumulation of ATF4 in the nuclear fraction was noted three hours after exposure to IQOS aerosols. Upon an examination of changes in factors in the GSH biosynthetic system, a significant increase in cystine concentration in the lung tissue was measured, and an increase in xCT expression level was observed in the cell membrane fraction three-six hours after IQOS exposure. Furthermore, characteristic changes in HO-1, a stress-response protein regulated by ATF4, was discovered six hours after IQOS exposure. Moreover, analysis of the upstream ATF4 regulatory system revealed that phosphorylation of eIF2α was enhanced in the lung cytoplasmic fraction three hours after exposure to IQOS aerosols. These findings suggest that ER stress might be induced as an early response to IQOS aerosol exposure, accompanied by the activation of the eIF2α-ATF4 axis. These intracellular changes have also been reported after exposure to combustible cigarette smoke. Thus, the acute response found in the lungs of mice in the present study demonstrate that the inhalation of aerosols from IQOS elicits a biological response similar to that of combustible cigarette smoke. In conclusion, our results provide evidence that the biological effects of HTPs, such as IQOS, cannot be ignored in the lungs.

E-cigarettes and smoking cessation among adolescent smokers

Smokers of any age can reap substantial health benefits from quitting or reducing their smoking. E-cigarettes have been promoted as a potentially promising product for tobacco harm reduction because e-cigarettes deliver nicotine vapor without many of the hazardous chemical combustion byproducts produced by combustible cigarette smoking. However, there remains an ongoing debate on whether the use of e-cigarettes is effective in combustible cigarette smoking cessation or reduction in both adolescents and adults. Our study uses data from the 2015 (baseline) and from the 2017 (follow-up) waves of the Taiwan Adolescent to Adult Longitudinal Study (TAALS), which is a large nationwide representative cohort study of health behaviors among adolescents in Taiwan. We analyzed the data using logistic regression and multivariate regression with a post-stratification weighting procedure. Among the 474 adolescent combustible cigarette users at baseline, the use of e-cigarettes had no association with smoking cessation (aRR = 0.99, 95% CI = 0.66, 1.50). Furthermore, the use of e-cigarettes was also not associated with change in combustible cigarette consumption among all adolescent combustible cigarette users at follow-up (Coef. = 0.62, 95% CI = − 36.85, 38.09). In summary, our findings suggest that e-cigarettes may not aid tobacco control among adolescent smokers. Policy makers should be cautious of the potential harms that e-cigarette may bring to young people when they are developing e-cigarette regulations.

Non-Targeted Chemical Characterization of JUUL-Menthol-Flavored Aerosols Using Liquid and Gas Chromatography

The aerosol constituents generated from JUUL Menthol pods with 3.0% and 5.0% nicotine by weight (Me3 and Me5) are characterized by a non-targeted approach, which was developed to detect aerosol constituents that are not known to be present beforehand or that may be measured with targeted methods. Three replicates from three production batches (n = 9) were aerosolized using two puffing regimens (intense and non-intense). Each of the 18 samples were analyzed by gas chromatography electron ionization mass spectrometry and by liquid chromatography electrospray ionization high-resolving power mass spectrometry. All chemical constituents determined to differ from control were identified and semi-quantified. To have a complete understanding of the aerosol constituents and chemistry, each chemical constituent was categorized into one of five groups: (1) flavorants, (2) harmful and potentially harmful constituents, (3) leachables, (4) reaction products, and (5) chemical constituents that were unable to be identified or rationalized (e.g., chemical constituents that could not be categorized in groups (1–4). Under intense puffing, 74 chemical constituents were identified in Me3 aerosols and 68 under non-intense puffing, with 53 chemical constituents common between both regimens. Eighty-three chemical constituents were identified in Me5 aerosol using an intense puffing regimen and seventy-five with a non-intense puffing regimen, with sixty-two chemical constituents in common. Excluding primary constituents, reaction products accounted for the greatest number of chemical constituents (approximately 60% in all cases, ranging from about 0.05% to 0.1% by mass), and flavorants—excluding menthol—comprised the second largest number of chemical constituents (approximately 25%, ranging consistently around 0.01% by mass). The chemical constituents detected in JUUL aerosols were then compared to known constituents from cigarette smoke to determine the relative chemical complexities and commonalities/differences between the two. This revealed (1) a substantial decrease in the chemical complexity of JUUL aerosols vs. cigarette smoke and (2) that there are between 55 (Me3) and 61 (Me5) unique chemical constituents in JUUL aerosols not reported in cigarette smoke. Understanding the chemical complexity of JUUL aerosols is important because the health effects of combustible cigarette smoke are related to the combined effect of these chemical constituents through multiple mechanisms, not just the effects of any single smoke constituent.

Stepwise Tobacco Price Increase and Smoking Behavioral Changes in Japan: The Japan "Society and New Tobacco" Internet Survey 2017-2021 Longitudinal Study.

Tobacco price increase is an effective measure to reduce tobacco smoking. In Japan, the price of combustible cigarettes increased in 2018 and 2020, and that of heated tobacco products increased every year from 2018 to 2020 by tobacco excise taxation. Also, the general consumption tax increase in 2019 slightly raised the retail prices of tobacco products. We investigated the impact of this stepwise tobacco price increase on combustible cigarette smoking status among Japanese adults. Five waves of annual longitudinal data (2017-2021) from The Japan "Society and New Tobacco" Internet Survey (JASTIS) (31 930 observations of 11 896 individuals) were analyzed. Multivariable logistic regression with a generalized estimating equation was fitted, adjusting for the prefecture of residence, age, sex, socioeconomic status, health status, alcohol drinking, former smoker's duration of smoking cessation, and the current smoker's number of cigarettes smoked per day. The 2018 price increase was associated with a reduction in relapse (adjusted odds ratio [aOR] 0.54, 95% confidence interval [CI] 0.42-0.68) and an increment in cessation (aOR 1.20, 95% CI 1.02-1.42). The price increase in 2019 was not associated with relapse (aOR 0.84, 95% CI 0.63-1.10) or cessation (aOR 0.95, 95% CI 0.80-1.13). The 2020 price increase was associated with a reduction in relapse (aOR 0.59, 95% CI 0.42-0.81) and an increment in cessation (aOR 1.45, 95% CI-1.21, 1.73). The price increase caused by tobacco excise taxation was associated with a reduction in combustible cigarette smoking. Japan introduced a policy of stepwise increase in tobacco excise taxation in 2018. We analyzed five-wave longitudinal data to investigate the impact of the policy. Tobacco price increases in 2018 and 2020 were associated with a reduction in combustible cigarette smoking. Tobacco price increases in 2019 by general consumption tax were not associated with a change in combustible cigarette smoking.