Dual Users Compared to Smokers: Demographics, Dependence, and Biomarkers

Understanding the motivational mechanisms for smoking and vaping among dual users and exclusive smokers

BACKGROUND

Understanding the motivational processes that influence e-cigarette use in a laboratory setting may help elucidate mechanisms that support long-term ecigarette use, which could have significant clinical and public health consequences.

METHODS

Secondary analyses were conducted on data from exclusive smokers (N=47) and dual users (N=88) who underwent a laboratory ad lib use session. Participants were given 10minutes to smoke (exclusive smokers) or vape (dual users) as much as they wanted. Withdrawal was assessed pre- and post-use. Smoking and vaping behavior was coded from session videos. Person-level predictors included cigarette/ecigarette craving-relief expectancies, demographics, and cigarette/e-cigarette use and dependence. Smoking and vaping status was assessed at Year 1 using self-reported 30-day point prevalence. Data were analyzed using general linear models and logistic regressions.

RESULTS

Both groups reported reductions in withdrawal after product use, including cigarette craving. Baseline e-cigarette craving-relief expectancies, pre-session ecigarette craving, heaviness of e-cigarette use, and relative e-cigarette dependence were significant univariate predictors of continued vaping in dual users at Year 1 (ORs>1.04, ps<.05). Dual users and exclusive smokers did not differ on use behavior (i.e., average number of puffs, ps>.16).

CONCLUSIONS

E-cigarette use alleviated withdrawal, including cigarette and e-cigarette craving, in dual users. Laboratory use behavior did not differ between dual users using e-cigarettes and exclusive smokers using cigarettes. Greater e-cigarette craving-relief expectancies, e-cigarette craving, heaviness of e-cigarette use, and morning product use pattern ('relative dependence') may reflect mechanisms that sustain e-cigarette use.

Nicotine acute impact on RNFL: a comparative analysis of smoking cessation aids including nicotine gum and electronic cigarettes

PURPOSE

To investigate the immediate impact of nicotine consumption on Retinal Nerve Fiber Layer (RNFL) thickness in healthy young individuals, comparing nicotine gum and electronic cigarette (vaping) as delivery methods.

MATERIALS AND METHODS

Twenty participants underwent RNFL measurements at baseline, 30, and 60 minutes after consuming 4 mg of nicotine, based on product labeling and specifications. Measurements were obtained using optical coherence tomography (OCT) (Topcon 3D OCT-1 Maestro System). Nicotine was delivered through either nicotine gum or vaping.

RESULTS

Both nicotine gum and vaping led to a statistically significant increase in RNFL thickness, with no significant difference between the two methods. The analysis revealed that area, time, and visit factors significantly affected RNFL scores. Stratification by smoking type (tobacco, vaping, dual) demonstrated significant effects for area, time, and visit factors, with an interaction effect among these factors.

CONCLUSIONS

The findings highlight the acute impact of nicotine intake on RNFL thickness in young healthy smokers. Researchers and clinicians should account for recent nicotine exposure when evaluating RNFL thickness, particularly within the first hour post-smoking. The observed significant effects warrant further research, especially in older or health-compromised populations, to improve clinical protocols and diagnostic evaluations across different demographics.

Association between prolonged dual use of cigarettes and E-cigarettes and psychosocial factors among U.S. Smokers: Secondary data analysis from the 2013 to 2019 PATH study

Objective

Dual use of combustible cigarettes and e-cigarettes is common among U.S. tobacco users, yet mis-perceptions about the harm of dual use persist, often oversimplifying its multifaceted exposure and health impacts. To address this gap, we evaluated the association of prolonged dual use (consecutive use for more than 1 year) with psychosocial factors, including perceptions of absolute and relative harm of e-cigarettes, social norms, and intentions to quit smoking, among U.S. adult smokers over time.

Methods

Using the data from Waves 1 to 5 (2013-2019) from the Population Assessment of Tobacco and Health (PATH) Study, we characterized dual use and prolonged dual use by sociodemographics and psychosocial factors among U.S. adult smokers. We examined the association between dual use, including prolonged dual use, and psychosocial factors over time using logistic regression.

Results

Dual use of smokers decreased from 19.8 % in 2013 to 16.4 % in 2019, and prolonged dual use among dual users decreased from 40.0 % in 2013 to 27.4 % in 2019. Prolonged dual users, independent of frequency of use, presented significantly higher cigarette dependence than temporary dual users. The perception of absolute e-cigarette harm (perceiving e-cigarettes as very or extremely harmful) was negatively associated with prolonged dual use. No significant association was found between prolonged dual use and perception of relative e-cigarette harm (perceiving e-cigarettes are less harmful than cigarettes) as well as with intentions to quit smoking and beliefs that most people disapprove of e-cigarette use.

Conclusion

Increased perceptions of absolute harm of e-cigarettes, rather than relative harm, appear to decrease prolonged dual use. Public health strategies should consider further emphasis in educating users of the absolute harm, as opposed to endorsing e-cigarette use as a harm reduction alternative, in their tobacco cessation efforts to further discourage dual use.

Combustible cigarette smokers versus dual combustible and electronic users: Evaluation of differences in anxiety, depression, and transdiagnostic constructs among Latinx adults

Research on dual combustible and electronic nicotine use among Latinx persons is needed to better understand patterns of use because this group is an established tobacco disparities population. Negative emotional symptoms and related processes (e.g., reactive transdiagnostic vulnerabilities) have been among the most prominent factors linked to the onset, maintenance, and relapse of smoking. As such, the current study sought to compare levels of mental health symptoms among combustible users compared to dual combustible and electronic users among Latinx persons who smoke. The current sample consisted of 297 adult Latinx daily cigarette smokers (Mage = 35.90 years; SD = 8.87; age range 18-61; 36.4% female), of which 92 reported current dual use of an e-cigarette (Mage = 33.34 years; SD = 7.75; age range 19-60; 28.3% female). Differences in anxiety, depression, anxiety sensitivity, emotion dysregulation, and distress tolerance were examined, and we hypothesized that dual users would showcase higher mental health problems. Results indicated that adult Latinx dual users evidenced greater levels of anxiety, depression, emotional dysregulation, anxiety sensitivity, and lower levels of distress tolerance compared to combustible users. The current study sheds light on the clinical importance of affective differences among dual versus combustible Latinx smokers.

Concurrent E-cigarette Use While Enrolled in a Smoking Cessation Program: Associations Between Frequency of Use, Motives for Use, and Smoking Cessation

INTRODUCTION

Trial evidence suggests that e-cigarettes may aid in quitting smoking, while observational studies have found conflicting results. However, many observational studies have not adjusted for important differences between e-cigarette users and non-users.

AIMS AND METHODS

We aimed to determine the association between e-cigarette use frequency and motivation to use e-cigarettes to quit smoking, and smoking cessation using data from Canada's largest smoking cessation program. Participants who completed a baseline assessment and 6-month follow-up questionnaire were divided post hoc into four groups based on their self-reported e-cigarette use during the 30 days before baseline: (1) non-users; (2) users of e-cigarettes not containing nicotine; (3) occasional users; and (4) frequent users. Occasional and frequent users were further divided into two groups based on whether they reported using e-cigarettes to quit smoking. Abstinence at 6-month follow-up (7-day point prevalence abstinence) was compared among groups.

RESULTS

Adjusted quit probabilities were significantly higher (both p < .001) for frequent baseline e-cigarette users (31.6%; 95% CI = 29.3%, 33.8%) than for non-users (25.8%; 25.3% and 26.3%) or occasional users (24.2%; 22.5% and 26.0%). Unadjusted proportions favored non-users over occasional users (p < .001), but this was not significant after adjustment (p = .06). People using e-cigarettes to quit smoking were not likelier than other users to be successful, but were likelier to report frequent e-cigarette use during follow-up.

CONCLUSIONS

Frequent baseline e-cigarette use predicted successful smoking cessation, compared to occasional and non-users. Use of e-cigarettes to quit did not predict smoking cessation but was associated with continued use during follow-up, perhaps due in part to planned transitions to e-cigarettes.

IMPLICATIONS

Prior observational studies investigating e-cigarette use for smoking cessation have found that occasional users have poorer outcomes than either frequent or non-users. Consistent with these studies, occasional users in our data also had poorer outcomes. However, after adjustment for variables associated with cessation success, we found that cessation probabilities did not differ between occasional and non-users. These findings are consistent with trial data showing the benefit of e-cigarette use among people trying to quit smoking. Results of this study suggest that differences between trials and previous observational studies may be because of unaddressed confounding in the latter.

Assessing acute nicotine impact on choroidal thickness: a randomized, double-blinded study comparing smoking cessation aids, including nicotine gum and electronic cigarettes

PURPOSE

To explore whether differences in choroidal thickness arise from nicotine consumption in healthy young individuals, specifically comparing the effects of nicotine gum to electronic cigarette (vaping), while maintaining a consistent 4 mg nicotine dosage.

METHODS

In a randomized double-blinded prospective cross-sectional study, 20 healthy participants (mean age ± standard deviation: 23 ± 2.36 years) were randomly assigned to either the nicotine gum or vaping group. Choroidal thickness (ChT) measurements were conducted using optical coherence tomography (OCT) (Topcon 3D OCT-1 Maestro System) at baseline, 30, and 60 min after ingesting 4 mg of nicotine, with ChT measurements taken from five different horizontal areas.

RESULTS

Neither the nicotine delivery method (gum or vaping) demonstrated a statistically significant impact on ChT mean scores among subjects in the five measured areas at baseline, 30, and 60 min (p > 0.05). However, significant differences were observed in ChT mean scores within subjects across the five areas (F (1.83, 72) = 36.43, p < 0.001), regardless of other study factors such as group, time, and visit (p > 0.05). A statistically significant interaction was identified between the factors of area and time concerning participants' ChT mean scores when stratified by the type of smoking (tobacco, vaping, and dual) (p = 0.003).

CONCLUSION

The results of this study revealed that nicotine, up to particular concentration of 4 mg, does not have a statistically significant vasoconstrictive effect on choroidal thickness, regardless of the delivery method, within the examined group. These findings offer valuable insights into the relationship between nicotine intake and choroidal dynamics in young adults.

Examining the correlates of cigarette smoking, e-cigarette use and dual use among Canadian post-secondary students

Many Canadians use nicotine products such as cigarettes and e-cigarettes. A particular subpopulation of concern is post-secondary students given they have a higher prevalence of use. Many correlates of cigarette smoking and e-cigarette use have been identified. However, less focus has been on examining the correlates of cigarette smoking, e-cigarette use and dual use. This study explores the correlates of different nicotine modality use in post-secondary students. Using data from the Canadian Campus Wellbeing Survey (CCWS; n = 27,164), a multi-level nominal regression assessed the correlates of nicotine modality use. In comparison to individuals who were <20, individuals 20-24 (OR = .448, 95% CI .321, .625), 25-29 (OR = .140, 95% CI .093, .212), 30-34 (OR = .076, 95% CI .046, .125) and over 35 (OR = .041, 95% CI .024, .071) had lower odds of e-cigarette use compared to cigarette smoking. Identifying as a woman (OR = 1.553, 95% CI 1.202, 2.006), non-heterosexual (OR = .642, 95% CI = .485,0.851), current cannabis user (OR = 1.651, 95% CI 1.296, 2.104), and being an international student (OR = .350, 95% CI .251, .487) also impacted the odds of e-cigarette use vs only cigarette smoking. When considering dual use vs cigarette smoking, individuals aged 20-24 (OR = .491, 95% CI .337, .717), 25-29 (OR = .221, 95% CI .137, .357), 30-34 (OR = .163, 95% CI .091, .292) and over 35 (OR = .122, 95% CI .065, .230) had lower odds than individuals <20. Current cannabis use (OR = 1.680, 95% CI = 1.209, 2.138), binge drinking (OR = 1.885, 95% CI 1.384, 2.568), and international student status (OR = .689, 95% CI .476, .996) also impacted cigarette smoking vs dual-use. Overall, a minority of young adults (11.5%) at post-secondary institutions in our sample use nicotine products, and the higher prevalence of e-cigarette use warrants continued monitoring. Health promotion campaigns addressing e-cigarette use are required. Additionally, tailored intervention efforts could prioritize the treatment needs of international students studying in Canada.

Variances in Smoking Expectancies Predict Moment-to-Moment Smoking Behaviors in Everyday Life

BACKGROUND

Many policy decisions about tobacco control are predicated on rational choice models, which posit (1) that smokers are aware of the risks of cigarettes and (2) that perceived risks have a consistent influence on continued smoking behavior. However, research shows that beliefs about smoking may be vulnerable to changes in internal and external contexts.

METHODS

Using ecological momentary assessment, we tested this by measuring how smokers' (N = 52) beliefs about smoking varied over time. Four times per day over 1 week, participants responded to measures of smoking intentions, risk perceptions, mood and social outcome expectancies, and internal and external contextual factors.

RESULTS

We analyzed this data using multilevel modeling, finding that both smoking intentions, risk perceptions, and expectancies differed between participants as well as between moments.

CONCLUSION

Risk perceptions and mood expectancies were a significant predictor of intentions to smoke in the next 30 min, illustrating the importance of these beliefs in decisional processes. This study was preregistered at the Open Science Foundation: https://osf.io/wmv3s/?view_only=71ad66d3ce3845fcb3bf2b9860d820c9 . Our analytic plan was not preregistered.

Symptoms of nicotine dependence by e-cigarette and cigarette use behavior and brand: A population-based, nationally representative cross-sectional study

BACKGROUND

Many modern e-cigarette brands contain equivalent or higher nicotine levels than traditional cigarettes.

OBJECTIVE

To examine differences in four nicotine dependence indicators (i.e., use within 30minutes of waking, cravings, needing to use, and frequent use) among adolescents (aged 12-17 years) with past 30-day (P30D) exclusive use of e-cigarettes, cigarettes, or dual use of both.

METHODS

Data were from Wave 5 (2018-2019) of the Population Assessment of Tobacco and Health (PATH) study (n=1060; N=2053,659). Multivariable logistic regression was performed to determine differences in indicators by P30D e-cigarette and cigarette use behavior (exclusive vs. dual use) and brand (e-cigarette use: JUUL vs. non-JUUL vs. Unknown).

RESULTS

The odds of frequent use among adolescents with JUUL (AOR: 2.11; 95% CI=1.02-4.37) and non-JUUL (AOR: 2.12; 95% CI=0.95-4.77) use were similar and paralleled that for dual use (AOR: 3.50; 95% CI=1.46-8.43) but were stronger (JUUL only) than exclusive cigarette use. The odds of using within 30minutes of waking for adolescents with JUUL (AOR: 2.23; 95% CI=0.80-6.25) and non-JUUL (AOR:1.42; 95% CI=0.47-4.32) use were similar and paralleled that for both dual (AOR=3.00; 95% CI=1.01-8.88) and exclusive cigarette use. For adolescents who used unknown brands, the odds of all indicators paralleled exclusive cigarette use but were lower than JUUL, non-JUUL, and dual use.

CONCLUSION

Compared to exclusive cigarette use, symptoms of nicotine dependence are similar for adolescents with exclusive e-cigarette use, irrespective of brand. Symptoms of nicotine dependence for JUUL and non-JUUL use parallel dual use. Tobacco regulation should consider these findings when assessing the abuse liability of e-cigarettes.

Differences in Pain Severity and Interference between Latinx Combustible Cigarette Smokers and Dual Users with Current Pain

Latinx individuals who smoke represent a tobacco health disparities group. Yet, limited research has focused on examining dual combustible and electronic cigarette use among Latinx populations. Importantly, Latinx persons who smoke also evince elevated rates of pain problems and symptoms and prior research has consistently linked pain problems and severity to smoking prevalence, maintenance, and behavior. Accordingly, the current study sought to build from the limited work that exists among dual combustible cigarette and electronic cigarette Latinx users comparing levels of pain severity and interference. The current sample consists of 196 adult Latinx daily cigarette smokers (35.48 years old; 39.4% female), of which 72 reported current daily dual use of an e-cigarette. Results indicated that Latinx dual users reported greater levels of pain severity (ηp2 = .12) and pain interference (ηp2 = .10) than exclusive combustible cigarette users. The study adds uniquely to the limited literature on the clinical importance of dual cigarette use in relation to pain severity and interference in that pain may serve as an important risk factor for the initiation and maintenance of dual use for increased analgesic nicotine effects.

Socio-demographic Correlates of Electronic Cigarette and Cannabis Co-use Among Naïve and Tobacco Adolescent Users

The increasing co-use of e-cigarette and cannabis among youth has become a public health challenge. The present analyses aimed to identify prevalence and correlates of past-month co-use of e-cigarettes and cannabis among adolescents with and without prior tobacco use. For this panel study, 5 years of cross-sectional data (2014-2018) were used from 8th, 10th-, and 12th-grade adolescents in the Monitoring the Future study, a nationally representative survey of U.S. students. We examined prevalence and correlates of e-cigarettes and cannabis co-use among adolescents who had ever used tobacco (n = 15,136) and among those who had never used tobacco (n = 56,525). Adolescents who had ever used tobacco showed significantly higher rates of e-cigarettes and cannabis co-use compared to adolescents who had never used tobacco (17.1% vs. 2.2%, p < 0.01). Results from adjusted multinomial regression models showed that overall, Black and Hispanic adolescents tobacco users were less likely than Whites to co-use e-cigarettes and cannabis. Black adolescents who had used tobacco previously were more likely than Whites to have used cannabis exclusively. Black and Hispanic tobacco-naïve adolescents were more likely than Whites to have used cannabis exclusively, while Black tobacco-naïve adolescents were less likely to use e-cigarettes exclusively or co-use e-cigarettes and cannabis. Overall, males and twelve graders were more likely than males and eight graders to use or co-use cannabis or e-cigarettes, respectively. Among lifetime tobacco users, higher levels of parental education were associated with co-use of cannabis and e-cigarettes. Racial/ethnic-specific patterns of e-cigarette and cannabis co-use depends on adolescents' prior experience with tobacco. The higher rates of use and co-use of e-cigarettes and cannabis among prior tobacco users suggest that targeted interventions are needed for this group. Identified socio-demographic groups at higher risk of co-use of e-cigarettes and cannabis need to be further studied.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Comparison of biomarkers of exposure among US adult smokers, users of electronic nicotine delivery systems, dual users and nonusers, 2018-2019

The harm caused by cigarette smoking is overwhelmingly due to byproducts of tobacco combustion. Electronic Nicotine Delivery Systems (ENDS) provide nicotine to users without combustion, and may support tobacco harm reduction among cigarette smokers who would not otherwise quit in the near term. Analyses of Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study compared biomarkers of exposure (BOE) levels for nicotine, 3 metals, 2 tobacco-specific nitrosamines and 14 smoking-related volatile organic compounds in 151 exclusive ENDS users, 1341 exclusive cigarette smokers, 115 dual users (cigarettes and ENDS), and 1846 past 30-day nonusers of tobacco, adjusting for demographics. Nicotine exposure in ENDS users and dual users did not significantly differ from smokers. Among ENDS users, 16 of 18 other BOEs were significantly lower than smokers'; 9 BOEs were not significantly different from nonusers. Among dual users smoking < 10 cigarettes/day, 15 of 18 non-nicotine BOEs were significantly lower than smokers', whereas in dual users smoking ≥ 10 cigarettes per day none of the BOEs significantly differed from smokers'. In this representative sample of US adults, exclusive use of ENDS (vs. cigarette smoking) was associated with much lower exposures to many harmful chemicals associated with smoking-related disease. BOE levels in dual users were directly related to their cigarette consumption. These BOE data provide further evidence that ENDS expose users to substantially lower levels of toxicants than combustible cigarettes, confirming their potential for harm reduction.

Specific biomarker comparison in current smokers, e-cigarette users, and non-smokers

INTRODUCTION

This study aims to address the existing gap in the literature, while adding evidence, by comparing tobacco-specific biomarkers (cotinine and nitrosamines: NNK, NNAL, NNN), and other biomarkers of e-cigarette use (humectants: glycerol, 1,2-PD, 1,3-PD) according to five study groups.

METHODS

A pooling analysis including two different studies was conducted. In both analyses, we took saliva samples from smokers (n = 409) and non-smokers (n = 154), dual tobacco and e-cig users (n = 92), exclusive e-cig user with nicotine (n = 158), and exclusive e-cig users without nicotine (n = 38). We analyzed and compared the geometric means (GM) and geometric standard deviations (GSD) of the concentration of tobacco-specific biomarkers, and e-cigarette biomarkers among groups. We used log-linear models adjusted for sex and age to model the change percentage and their 95% confidence intervals.

RESULTS

Cotinine was significantly higher in nicotine consumers and in e-cigarette users without nicotine when compared to non-smokers. TSNAs were generally significantly lower in non-smokers and higher in nicotine consumers. NNN and NNAL were lower in e-cigarette users with nicotine comparted to smokers, and NNN was higher in e-cigarette users without nicotine when compared to non-smokers. No differences were found in humectant biomarkers between e-cigarette groups.

CONCLUSIONS

Although there was a reduction in TSNAs in e-cigarette exclusive users compared to smokers, and a reduction of cotinine concentrations in e-cigarette exclusive users without nicotine compared to smokers, there are still high levels of these biomarkers when compared to non-smokers, which may be a clue towards the harmful effect of e-cigarettes.

Associations of dual use of tobacco cigarettes and e-cigarettes, sleep duration, physical activity and depressive symptoms among middle-aged and older Korean adults

AIM

There is limited evidence of the association between dual tobacco-e-cigarette use and health-related variables in Korea. Thus, this study aimed to investigate the associations between types of cigarette smoking, sleep duration, physical activity and depressive symptoms among Korean adults.

DESIGN

A cross-sectional study design using the 2019 Korean Community Health Survey.

METHODS

The study subjects consisted of 179,004 adults older than 40 years from a total of 229,099 individuals. Self-reported general characteristics, smoking history, sleep duration, physical activity and depressive symptoms were analysed.

RESULTS

In multinomial logistic regression, dual users of tobacco cigarettes and e-cigarettes were more likely to have sleep duration of less than 7 h per day and to report both mild and moderate-to-severe depressive symptoms than non-smokers. Single use of either cigarettes or e-cigarettes increased the risk of short sleep duration and moderate-to-severe depressive symptoms.

Associations of Demographics, Dependence, and Biomarkers With Transitions in Tobacco Product Use in a Cohort of Cigarette Users and Dual Users of Cigarettes and E-cigarettes

INTRODUCTION

It is uncertain whether e-cigarettes facilitate smoking cessation in the real world. We aimed to understand whether and how transitions among cigarette, e-cigarette, and dual use are associated with sociodemographics, dependence measures, and biomarkers.

AIMS AND METHODS

We followed 380 adult daily cigarette users and dual users every 2 months for up to 2 years. We estimated transition rates between noncurrent, cigarette-only, e-cigarette-only, and dual use states using a multistate transition model. We estimated univariable hazard ratios (HR) for demographics, dependence measures for cigarettes and e-cigarettes, biomarkers, spousal or partner behaviors, and other measures.

RESULTS

We estimated that participants transitioned from cigarette-only to e-cigarette-only through a period of dual use. Dual users ceased smoking (transitioning to e-cigarette-only use) at a greater rate than cigarette-only users did (HR 2.44, 95% CI: 1.49, 4.02). However, of the 60% of dual users estimated to transition to single product use in 1 year, 83% would transition to cigarette-only use and only 17% to e-cigarette-only use. E-cigarette dependence measures were generally associated with reduced e-cigarette cessation rather than enhanced cigarette cessation. E-cigarette users motivated by harm or toxicity reduction or because of restrictions on where or when they could smoke had reduced rates of smoking relapse. Cigarette dependence and spousal smoking were barriers to cigarette cessation for dual users, while using e-cigarettes first in the morning, motivation to quit smoking, and sensory, social, and emotional enjoyment of e-cigarettes (secondary dependence motives) were facilitators of smoking cessation among dual users.

CONCLUSIONS

Tobacco control policy and interventions may be informed by the barriers and facilitators of product transitions.

IMPLICATIONS

Although e-cigarettes have the potential to promote smoking cessation, their real-world impact is uncertain. In this cohort, dual users were more likely to quit smoking than cigarette-only users, but the overall impact was small because most dual users returned to cigarette-only use. Moreover, e-cigarette dependence promoted continued dual use rather than smoking cessation. Yet, high motivation to quit smoking and the sensory, social, and emotional enjoyment of e-cigarettes facilitated smoking cessation in dual users. Better understanding the barriers and facilitators of transitions can help to develop regulations and interventions that lead to more effective use of e-cigarettes for smoking cessation.

Associations Between E-cigarettes and Subsequent Cocaine Use in Adolescence: An Analysis of the UK Millennium Cohort Study

INTRODUCTION

Nicotine exposure via early combustible cigarette smoking can prime the adolescent brain for subsequent cocaine use. However, there is limited evidence whether e-cigarette use, a nicotine delivery system that is increasingly popular among youth, is associated with later cocaine use. We examine the association between e-cigarette use by the age of 14 years and cocaine use by the age of 17 years.

AIMS AND METHODS

The Millennium Cohort Study is a nationally representative sample of 18 552 9-month-old children born between September 2000 and January 2002 in the United Kingdom. Follow-up interviews and surveys were collected from children and their caregivers at modal ages 3, 5, 7, 9, 11, 14, and 17 years. Our analytic sample included 340 youth who had used e-cigarettes by age 14 years (exposure variable), matched using coarsened exact matching, to 4867 nicotine naïve youth on childhood common liability confounders and demographics measured from infancy to age 11. The outcome was cocaine use by the modal age of 17 years.

RESULTS

Of the 5207 successfully matched youth, 7.6% of adolescent e-cigarette users by age 14 years used cocaine by age 17 years versus 3.1% of non-e-cigarette users. Multivariable logistic regression in the matched sample indicated that e-cigarette use by age 14 years was associated with 2.7 times higher odds of cocaine use by age 17 years (95% CI, 1.75 to 4.28).

CONCLUSIONS

These findings in a UK sample showed that e-cigarette use in early adolescence is associated with higher odds of cocaine use later in adolescence, similar to risks posed by tobacco cigarette smoking.

IMPLICATIONS

In this large-scale prospective cohort study (n = 5207), youth who had used e-cigarettes by the age of 14 years were matched to nicotine naïve youth on childhood common liability confounders and demographics measured from infancy to age 11 years (e.g. school engagement, risk-taking propensity, delinquency, peer and parental smoking, parental educational attainment). After matching, 7.6% of age 14 years e-cigarette users had subsequently used cocaine by the age of 17 years versus 3.1% of non-e-cigarette users. Although e-cigarettes are promoted as a strategy for nicotine-dependent users to reduce the harms of combustible cigarettes, the evidence here suggests that for nicotine naïve youth, they may increase the risk of subsequent cocaine use.

Toward a better understanding of adult dual use of cigarettes and e-cigarettes based on use intensity and reasons for dual use

BACKGROUND

Dual use of combustible cigarettes and e-cigarettes is an emerging phenomenon among U.S. adults. Literature suggests two primary reasons for this emerging use (i.e., to help quit smoking and to stealth vape). This study investigated user profiles based on use intensity and the reasons for dual use.

METHODS

A total of 1,151 U.S. adult dual users were drawn from the 2018-2019 Tobacco Use Supplement to the Current Population Survey. We divided them into four groups: daily dual users (n = 189), predominant smokers (n = 608), predominant vapers (n = 143), and non-daily dual users (n = 211). We performed weighted multivariable logistic regressions to identify factors associated with the two primary reasons for dual use.

RESULTS

3 in 10 of U.S. adult dual users used e-cigarettes to help quit smoking while 2 in 10 of U.S. adult dual users used e-cigarettes to stealth vape. Compared to daily dual users, predominant smokers [adjusted odds ratio (AOR) = 0.61, 95% CI = 0.23, 0.62] were less likely to use e-cigarettes to help quit smoking whereas predominant vapers (AOR = 1.80, 95% CI = 1.04, 3.13) were more likely to use e-cigarettes to help quit smoking and less likely to use e-cigarettes to stealth vape (AOR = 0.30, 95% CI = 0.10, 0.89).

CONCLUSIONS

There was notable heterogeneity among the four groups of dual users. As the landscape of tobacco use is rapidly changing with an increasing popularity of e-cigarettes, reasons as well as behaviors of dual users need to be regularly monitored for effective tobacco control.

Association between smoking behavior and serum uric acid among the adults: Findings from a national cross-sectional study

BACKGROUND

Gout incidence is increasing worldwide; appropriate management of serum uric acid levels and a healthy lifestyle may help its prevention. The popularity of electronic cigarettes and the resultant emergence of dual smokers is increasing. Despite many studies on the effects of various health behaviors on serum uric acid levels, the association between smoking and serum uric acid levels remains controversial. This study aimed to investigate the association between smoking and serum uric acid levels.

METHODS

In this study, total sample of 27,013 participants (11,924 men and 15,089 women) were analyzed. This study used data from the Korea National Health and Nutrition Examination Survey (2016-2020) and grouped adults into dual smokers, single smokers, ex-smokers, and non-smokers. Multiple logistic regression analyses were performed to investigate the association between smoking behavior and serum uric acid levels.

RESULTS

Compared to male non-smokers, male dual smokers had significantly higher serum uric acid level (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.08-1.88). In female, serum uric acid level was higher among single smokers than non-smokers (OR, 1.68; 95% CI, 1.25-2.25). Higher serum uric acid levels were more likely to be present in male dual smokers with a > 20 pack-year smoking habit (OR, 1.84; 95% CI, 1.06-3.18).

CONCLUSION

Dual smoking may contribute to high serum uric acid levels in adults. Thus, serum uric acid levels should be properly managed through smoking cessation.

Dual users' perceptions of the addictive properties of cigarettes versus E-cigarettes

INTRODUCTION

Electronic cigarettes ("e-cigarettes") are commonly promoted as a less-harmful alternative to combustible cigarettes, yet many individuals concurrently use both products ("dual users"). Little is known about the extent to which dual users' perceptions of the addictive properties of these products differ, or to what extent there are differences in the factors that elicit craving for each product.

METHODS

An online survey evaluated beliefs about the addictive properties of cigarettes vs e-cigarettes and the situational and affective precipitants of product craving, on a scale from 1 to 10, in a sample of Canadian adults that reported past-month use of combustible and e-cigarettes (N = 175; 79 female).

RESULTS

Participants rated cigarettes as more addictive than e-cigarettes, and on average reported higher levels of dependence on combustible cigarettes. While the addictive properties of both combustible and e-cigarettes were largely attributed to nicotine, non-nicotine factors (e.g. flavouring, other non-nicotine ingredients) were believed to make a relatively stronger contribution to the addictive properties of e-cigarettes, particularly among women. Participants reported greater increases in craving for combustible cigarettes in response to negative affective states and situational factors, and these effects were strongest among participants that displayed greater dependence on combustible tobacco relative to e-cigarettes.

CONCLUSIONS

Dual users perceived cigarettes to be more addictive than e-cigarettes and attributed the addictive properties of each product to different factors. Further, cravings for combustible cigarettes were more strongly linked to certain negative affective states and situational factors relative to e-cigarettes. Findings suggest that there may be limited substitutability between combustible and e-cigarettes.

Dual Use of Combustible Cigarettes and E-cigarettes: a Narrative Review of Current Evidence

Purpose of Review

E-cigarette use (vaping) among adults has increased, and various patterns of concurrent smoking and vaping (i.e., "dual use") have emerged. Understanding dual use is important for mitigating tobacco-related harm. This narrative review summarizes recent research on dual use, including prevalence and types of dual use, sociodemographic and psychiatric characteristics, nicotine dependence, reasons for dual use, harm perceptions, toxicant exposure, trajectories of dual use, and emerging treatments for dual use.

Recent Findings

Nearly half of e-cigarette users concurrently use cigarettes, and many smoke more frequently than they use e-cigarettes. This is concerning because dual users are exposed to both cigarette and potential e-cigarette toxicants and the data are mixed regarding the ability of e-cigarettes to promote smoking cessation.

Summary

Further work is needed to identify ways to increase complete smoking abstinence and optimize harm reduction among dual users, including strategies to encourage e-cigarette cessation after stopping smoking.

Efficacy of smartphone applications for smoking cessation in heavy-drinking adults: Secondary analysis of the iCanQuit randomized trial

INTRODUCTION

Efficacious smoking cessation treatments are needed for heavy-drinking adults who often have difficulty quitting smoking. In a secondary analysis of a parent randomized controlled trial, we explored the efficacy of an Acceptance and Commitment Therapy (ACT)-based smartphone application (iCanQuit) versus a US Clinical Practice Guidelines (USCPG)-based smartphone application (QuitGuide) for smoking cessation among heavy-drinking participants (4 + drinks/day for women; 5 + drinks/day for men).

METHODS

Participants were randomized to receive iCanQuit (n = 188) or QuitGuide (n = 160) for 12-months. Smoking cessation outcomes were measured at 3, 6 and 12-months. The primary outcome was self-reported complete-case 30-day point prevalence abstinence (PPA) at 12-months. Secondary outcomes were 7-day PPA at all timepoints; prolonged abstinence; and cessation of all nicotine-containing products at 12-months. Multiple imputation and missing-as-smoking analyses were also conducted. Exploratory outcomes were cessation of both smoking and heavy drinking and change in alcohol use (drinks/day) at 12-months. Treatment engagement and satisfaction and change in ACT-based processes were compared between arms.

RESULTS

Retention rate was 85% at 12-months and did not differ by arm. At 12-months, iCanQuit participants had nearly double the odds of smoking cessation compared to QuitGuide (complete-case 30-day PPA = 24% vs. 15%; OR = 1.87 95% CI: 1.03, 3.42). Findings were similar for the multiple imputation and missing-as-smoking outcomes at 12-months. Combined cessation of smoking and heavy drinking, and alcohol use at 12-months did not differ by arm. iCanQuit was significantly more engaging and satisfying than QuitGuide. Increased acceptance of thoughts about smoking mediated the effect of treatment on cessation of heavy drinking at 12-months.

CONCLUSIONS

The iCanQuit smartphone application was more efficacious and engaging for smoking cessation among heavy-drinking adults than a USCPG-based smartphone application.

A Comparison of Vaping Behavior, Perceptions, and Dependence among Individuals Who Vape Nicotine, Cannabis, or Both

Background: Electronic delivery systems (e.g., vapes, e-cigarettes) are now popular modes of cannabis and nicotine administration that are often used by the same individuals; however, we still know little about dual nicotine and cannabis vaping. Materials & Methods: An online convenience sample of adult nicotine and/or cannabis vape users residing in the United States completed a 60 min survey on sociodemographic characteristics, cannabis and/or nicotine vape use behaviors and dependence, reasons for vape use, and perceptions of benefits and harms. After data cleaning, we compared dual vs. nicotine-only and cannabis-only vape users with univariate statistics and step-wise hierarchical linear regression analyses. Additionally, we assessed the factor structure, internal consistency, and criterion and convergent validity of the Penn State Cannabis Vaping Dependence Index (PSCVDI). Results: The final sample included 357 dual, 40 cannabis, and 106 nicotine vape users. Compared to nicotine- and cannabis-only vapers, dual vapers started using their nicotine and cannabis vapes at a younger age (p < 0.001), used them for more years (p < 0.001), and were less likely to use their nicotine vape to replace combustible cigarettes (p = 0.047). Dual users vs. single-substance users did not have significantly higher nicotine or cannabis vape dependence scores after controlling for sociodemographic and use behaviors. The PSCVDI showed adequate validity for measuring cannabis vape dependence. Conclusions: This survey is the first to highlight important differences in vape use behaviors and reasons for use between dual vs. cannabis- and nicotine-only vape users.

Minor Tobacco Alkaloids as Biomarkers to Distinguish Combusted Tobacco Use From Electronic Nicotine Delivery Systems Use. Two New Analytical Methods

Biomarkers for the use of electronic nicotine delivery systems (ENDS) are desirable for studies of the health effects of electronic cigarettes and related devices. However, the aerosols inhaled from these devices do not contain substances that are unique to this class of products, i.e., substances that are not present in cigarette smoke or those that do not have common environmental or dietary sources. Consequently, identifying selective biomarkers for ENDS use remains a challenge. If co-use of conventional tobacco products can be definitively ruled out, then nicotine and its metabolites are suitable for assessing exposure. Self-reports from questionnaires are often used to obtain information on product use. But self-reports may not always be accurate, and are not amenable to obtaining quantitative information on exposure. An alternative approach is to use selective biomarkers for conventional tobacco products to definitively rule out their use. In this article, we describe two new LC-MS/MS methods for the minor tobacco alkaloids anabasine, anatabine, nicotelline, anatalline, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a tobacco-specific nitrosamine metabolite, all biomarkers that are selective for the use of conventional tobacco products. Applications of these biomarkers in studies of ENDS use and dual use of ENDS and conventional tobacco products are also discussed.

Comparison of nicotine dependence between single and multiple tobacco product users among South Korean adults

INTRODUCTION

The relationship between nicotine dependence and the use of multiple tobacco products, such as heated tobacco products (HTPs), electronic cigarettes (ECs), and combustible cigarettes (CCs), is not well investigated. We evaluated nicotine dependence symptoms among South Korean adults among single and multiple tobacco product users.

METHODS

We conducted an online survey involving 7000 adults aged 20–69 years in November 2018 and compared the nicotine dependence among single, dual, and triple use of tobacco products. Nicotine dependence was measured for ‘time to the first use of tobacco products within 5 min’, ‘awaking at night’, ‘strong craving’, ‘uncontrollable urge to smoke’, and ‘irritability or restlessness’. Adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for nicotine dependence symptoms based on the number of tobacco products were estimated using multivariable logistic regression analysis.

RESULTS

The current prevalence of use of tobacco products was 27.5%. Proportion of dual and triple uses were: 28.3%, 13.7% for CCs; 36.5%, 50.2% for ECs; and 54.0%, 33.1% for HTPs. Nicotine dependence tended to be higher as the number of tobacco products used increased for most measures, except for ECs with the measure ‘time to first use of tobacco products within 5 min’. The ORs of ‘awaking at night’ increased approximately three times for dual users (OR=2.87; 95% CI: 1.29–6.39, for current EC users) and seven times for triple users (OR=7.24; 95% CI: 3.66–14.31, for current HTP users) compared to that for single users.

CONCLUSIONS

Multiple tobacco product users reported higher nicotine dependence symptoms than single users. High nicotine dependence of multiple tobacco product users may hamper the future cessation of tobacco products, which can be challenging for future tobacco control policies in South Korea.

Is E-cigarette Use Associated With Persistence or Discontinuation of Combustible Cigarettes? A 24-Month Longitudinal Investigation in Young Adult Binge Drinkers

INTRODUCTION

It remains unclear whether electronic cigarette (e-cigarette) use promotes persistent combustible tobacco use or smoking discontinuation over time. Alcohol use is associated with a greater risk of adverse health effects of tobacco, and higher likelihood of e-cigarette use, making drinkers a high-priority subpopulation.

AIMS AND METHODS

This study examined longitudinal patterns of combustible tobacco and e-cigarette use over 24 months in young adult binge drinkers. A pooled dataset of 1002 (58.5% female; M age = 22.14) binge drinkers from the United States (60%) and Canada (40%) was used. The primary outcomes were past month combustible tobacco and e-cigarette use. Nicotine dependence was measured using the Fagerström Test of Cigarette Dependence. Alcohol severity was measured using the Young Adult Alcohol Consequences Questionnaire. Latent transition analysis (LTA) was used to identify patterns of cigarette smoking and e-cigarette use over 24 months.

RESULTS

The LTA yielded a four-class solution: (1) e-cigarettes-only users (prevalence over time: 7.75%-10.10%), (2) dual-product users (2.61%-9.89%), (3) combustible-only smokers (8.12%-20.70%), and (4) nonusers (61.66%-80.06%). Dual-product users predominantly transitioned to complete abstinence or exclusively e-cigarette use. In combustible-only smokers, the most common transition was to abstinence, followed by persistence of combustible-only status. At 24 months, 63% of e-cigarettes-only users transitioned to abstinence, with 37% continuing e-cigarettes-only use and 0% transitioning to dual or combustible cigarette use.

CONCLUSIONS

Dual-product use in young adult binge drinkers was associated with discontinuation of combustible tobacco over time, and e-cigarette-only use was not associated with subsequent combustible tobacco use.

IMPLICATIONS

These findings suggest that concurrent or exclusive e-cigarette use is not a risk factor for the persistence or development of combustible tobacco use in this subpopulation, with dual-product use reflecting a transitional pattern away from combustible use, toward discontinuation.

Relations among cigarette dependence, e-cigarette dependence, and key dependence criteria among dual users of combustible and e-cigarettes

Objective: The aim of this study was to examine dependence on combustible and e-cigarettes among users of both products (dual users), which may provide important insights into long-term use patterns. Method: Dual users (smoking daily for 3 months, using e-cigarettes at least once/week for the past month; N = 256; 45% women, 71% White, M age 39.0 years) not interested in quitting either product participated in a longitudinal, 2-year, observational study. At baseline, participants completed measures of combustible and e-cigarette dependence (Fagerström Test of Cigarette Dependence [FTCD], e-FTCD, Wisconsin Inventory of Smoking Dependence Motives [WISDM], e-WISDM, Penn State Cigarette Dependence Index, and Penn State E-Cigarette Dependence Index) and carried a study smartphone for 2 weeks to record cigarette and e-cigarette use events. Results: Most measures of dependence were product specific (e.g., FTCD and e-FTCD were not correlated, r = -0.003) and predicted product-specific outcomes (e.g., long-term use of that product). However, individuals used the two products for some of the same secondary dependence motives (e.g., weight control, cognitive and affective enhancement). These secondary, or instrumental, motives predicted use of both products at 1 year. Which product was used first in the morning was strongly related to product dependence scores and likelihood of continued product use at 1 year. Conclusions: Among dual users of combustible and e-cigarettes, measures of e-cigarette and cigarette dependence tended to be unrelated to one another, but dual users tended to use both products for the same instrumental motives. Which product is used first in the morning may serve as a valuable measure of relative dependence on the two products. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Changes in Biomarkers of Tobacco Exposure among Cigarette Smokers Transitioning to ENDS Use: The Population Assessment of Tobacco and Health Study, 2013-2015

Limited data are available for how biomarkers of tobacco exposure (BOE) change when cigarette smokers transition to using electronic nicotine delivery systems (ENDS). Using biomarker data from Waves 1 (2013-2014) and 2 (2014-2015) of the PATH Study, we examined how mean BOE concentrations, including metabolites of nicotine, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC) and metals, changed when 2475 adult smokers transitioned to using ENDS or quit tobacco products. Exclusive smokers who transitioned to dual use had a significant decrease in NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), but not nicotine metabolites, most PAHs, metals, or VOCs. Exclusive smokers who became dual users had significant reductions in total nicotine equivalents, NNAL, and 2CyEMA (acrylonitrile metabolite), but only in those who reduced cigarettes per day (CPD) by >=50%. Smokers who transitioned to exclusive ENDS use had significant reductions in most TSNAs, PAHs, and VOCs; however, nicotine metabolites did not decrease in dual users who became exclusive ENDS users. Smokers who quit tobacco use had significant decreases in nicotine metabolites, all TSNAs, most PAHs, and most VOCs. Cigarette smokers who became dual users did not experience significant reductions in most BOEs. Reductions were impacted by changes in CPD. However, transitioning from smoking to no tobacco or exclusive ENDS use was associated with reduced exposure to most BOEs measured. Future analyses could incorporate additional waves of PATH data and examine changes in biomarker exposure by ENDS device type and CPD.

Negative Affect and Cigarette Cessation in Dual Users of Cigarettes and Electronic Nicotine Delivery Systems

Objectives: Dual use of cigarettes and electronic nicotine delivery systems (ENDS) is increasingly common in adult smokers, who often report using ENDS to quit smoking. Elevated negative affect is an established predictor of increased difficulty quitting smoking combustible cigarettes but has not yet been examined in the context of cigarette cessation for dual users. Method: This study examined whether mood-related factors predict cigarette smoking cessation among dual users (N = 364) over 12-months. Self-reported cigarette smoking at 12 months, with abstinence defined as no smoking for the past 7 days, was the primary outcome variable. Logistic regression included baseline levels of depression symptoms (CES-D), anxiety symptoms (MASQ), and negative affect expectancies for smoking, with baseline nicotine dependence for cigarettes (NDSS), motivation to quit, age, race/ethnicity, rate of cigarette smoking at baseline, and ENDS usage at baseline and 12 months as covariates. Interactions between CES-D, MASQ, and negative affect expectancies were examined. We predicted that negative affect, especially for smokers who had high negative affect expectancies for smoking, would be negatively associated with quitting. Results: Contrary to expectations, negative affect constructs did not predict quitting. Baseline nicotine dependence for cigarettes, gender, and race/ethnicity significantly predicted the likelihood of cigarette cessation. Higher rates of ENDS use, higher motivation, and lower negative affect smoking expectancies were significantly correlated with quitting cigarettes. Conclusion: In this non-treatment seeking sample of dual users, negative affect did not predict cigarette cessation over and above nicotine dependence for cigarettes, gender, and race/ethnicity.

Changes in dependence, withdrawal, and craving among adult smokers who switch to nicotine salt pod-based e-cigarettes

BACKGROUND AND AIMS

For electronic cigarettes (e-cigarettes) to be a viable substitute for combustible cigarettes, it is likely that they must be rewarding enough for regular use, indicated by factors such as craving and dependence, important aspects of reinforcement. This study aimed to understand short-term changes in measures of nicotine dependence between groups differing by use trajectory in a switching trial, and within group changes of these measures.

DESIGN

Secondary data analysis of one arm of an e-cigarette randomized clinical trial.

SETTING

San Diego, California and Kansas City, Missouri, United States.

PARTICIPANTS

114 African American (n = 60) and Latinx (n = 54) smokers (58.8% male) attempting to switch to nicotine salt pod system (NSPS) e-cigarettes in a 6-week trial.

MEASUREMENTS

At week 6, participants were classified by use trajectory: exclusive smokers (n = 16), exclusive e-cigarette (n = 32), or dual users (n = 66). E-cigarette, cigarette, and total nicotine dependence (cigarette + e-cigarette), use patterns, cigarette craving and nicotine withdrawal, and cotinine were assessed at baseline and week 6 using standard measures.

FINDINGS

In between group comparisons, exclusive e-cigarette and dual users showed greater reductions in cigarette dependence (e-cigarette: -32.38, 95% CI = -37.7,-27.1; dual: -18.48, 95% CI = -22.2,-14.7), withdrawal (e-cigarette: -6.25, 95% CI = -8.52,-3.98; dual: -3.18, 95% CI = -5.02,-1.34), craving (e-cigarette: -11.44, 95% CI = -14.2,8.7; dual: -9.59, 95% CI = -11.6,-7.59), and cigarettes per day (CPD; e-cigarette: -11.19, 95% CI = -13.1,-9.27; dual: -9.39, 95% CI = -11.3, -7.52) compared with exclusive smokers. In within group analyses, e-cigarette and dual users showed reductions in craving and withdrawal from baseline to week 6. Exclusive e-cigarette and dual users, maintained cotinine levels (all Ps > 0.05) and showed reductions in CPD and cigarette dependence (all Ps < 0.01). Findings were inconclusive regarding changes in total nicotine dependence from baseline to week 6 among exclusive e-cigarette users (P = 0.123). Dual users showed increased total nicotine dependence (P < 0.001) and smokers showed decreased total dependence (P = 0.004).

CONCLUSIONS

Smokers who switch to nicotine salt pod system e-cigarettes maintain their nicotine levels and transfer their dependence, suggesting that nicotine salt pod system e-cigarettes have a similar reinforcement potential to cigarettes and facilitate switching.

Improving on estimates of the potential relative harm to health from using modern ENDS (vaping) compared to tobacco smoking

BACKGROUND

Although the harm to health from electronic nicotine delivery systems (ENDS) compared to smoked tobacco remains highly uncertain, society and governments still need to know the likely range of the relative harm to inform regulatory policies for ENDS and smoking.

METHODS

We identified biomarkers with specificity of association with different disease groupings e.g., volatile organic compound (VOCs) for chronic obstructive pulmonary disease; and tobacco-specific N´-nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons (PAHs) for all cancers. We conducted a review of recent studies (post January 2017) that compared these biomarkers between people exclusively using ENDS and those exclusively smoking tobacco. The percentage differences in these biomarkers, weighted by study size and adjusted for acrolein from other sources, were used as a proxy for the assumed percentage difference in disease harm between ENDS and smoking. These relative differences were applied to previously modelled estimates of smoking-related health loss (in health-adjusted life-years; HALYs).

RESULTS

The respective relative biomarker levels (ENDS vs smoking) were: 28% for respiratory diseases (five results, three studies); 42% for cancers (five results, four studies); and 35% for cardiovascular (seven results, four studies). When integrated with the HALY impacts by disease, the overall harm to health from ENDS was estimated to be 33% that of smoking.

CONCLUSIONS

This analysis, suggests that the use of modern ENDS devices (vaping) could be a third as harmful to health as smoking in a high-income country setting. But this estimate is based on a limited number of biomarker studies and is best be considered a likely upper level of ENDS risk given potential biases in our method (i.e., the biomarkers used being correlated with more unaccounted for toxicants in smoking compared to with using ENDS).

Predictors of smoking reduction among African American and Latinx smokers in a randomized controlled trial of JUUL e-cigarettes

INTRODUCTION

E-cigarette (e-cig) use is widespread and may play an important role in facilitating smoking reduction. Racial/ethnic minorities are less likely than Whites to use e-cigs and suffer disproportionate tobacco-related disease, making them a priority for harm reduction. This paper explores factors associated with smoking reduction among African American (AA) and Latinx smokers enrolled in a trial assessing toxicant exposure in those assigned to e-cigs or smoking as usual.

METHODS

Participants were randomized to receive 6 weeks of JUUL e-cigs or continue smoking cigarettes as usual (N = 187). This analysis focuses on 109 participants randomized to e-cigs. We modeled cigarettes smoked in the past week at baseline and week 6 as a function of a priori selected predictors (number of JUUL pods used throughout the study, baseline cigarette dependence, and baseline cotinine) using a Poisson model fit with generalized estimating equations.

RESULTS

Over the six-week study, cigarette smoking decreased from an average of 82.4 to 15.5 cigarettes per week. Greater numbers of JUUL pods used predicted a greater smoking reduction by week 6 (IRR = 0.94 [0.91, 0.96], p < 0.001). Higher baseline cigarette dependence (IRR = 1.03 [1.01, 1.05], p = 0.004), and baseline cotinine (IRR = 1.18 [1.03, 1.37], p = 0.020) predicted a lesser smoking reduction.

CONCLUSIONS

AA and Latinx smokers reduced their cigarette consumption while using JUUL e-cigs. Higher e-cig use during an intervention to switch to e-cigs to reduce harm may facilitate a transition to smoking fewer cigarettes, offering an opportunity to narrow smoking-related health disparities.

"It is the One Thing that has Worked": facilitators and barriers to switching to nicotine salt pod system e-cigarettes among African American and Latinx people who smoke: a content analysis

BACKGROUND

Electronic cigarettes are a harm reduction strategy for individuals who smoke cigarettes who cannot or do not want to quit using FDA-approved cessation methods. Identifying perceived facilitators and barriers to switching among people who smoke cigarettes is critical to optimizing health impact. This is particularly important for the most dominant e-cigarette device, nicotine salt pod electronic cigarettes. We investigate the experience using pod electronic cigarettes among African American and Latinx individuals who smoke, the two largest racial/ethnic minority groups who experience significant health disparities.

METHODS

From July 2018 to May 2019, adults who smoked cigarettes, age 21 + (N = 114; M age = 44.6, 59.6% male, 52.6% African American from Kansas City, 47.4% Latinx from San Diego) received JUUL-brand electronic cigarettes (referred to hereafter as JUUL) for 6 weeks and answered interview questions at week six. We inquired what they liked and disliked about using JUUL, what helped with switching and made switching difficult, future intentions for continued JUUL use, and how JUUL compared to past smoking reduction methods. Responses were coded into themes by independent raters. Theme frequencies were analyzed separately by race/ethnicity and week 6 use trajectory (exclusive JUUL use, dual JUUL and cigarette use, exclusive cigarette use).

RESULTS

Clean/smell was the aspect of using JUUL most commonly liked (23%), followed by convenience (19%). Coughing/harshness was a more common barrier to switching for African American (44%) than Latinx (9%), and for continuing cigarette use (56%) than for those who exclusively switched or dually used JUUL and combustible cigarettes (15-21%). Most (78% African American; 90% Latinx) reported that the benefits of using JUUL outweighed barriers, and this varied by JUUL use trajectory: 94% exclusive switch, 86% dual use, and 42% continued cigarette use. The majority said they would continue using JUUL to replace cigarettes (83% African American; 94% Latinx) and that JUUL worked better than other methods to reduce cigarettes (72%).

CONCLUSION

African American and Latinx individuals who smoked experience using pod electronic cigarettes was generally positive. Understanding facilitators and impediments to switching to electronic cigarettes among racial/ethnic minority people who smoke can inform harm reduction interventions and reduce tobacco-related health disparities. Trial Registration ClinicalTrials.gov Identifier: NCT03511001 posted April 27, 2018.

A pilot investigation of e-cigarette use and smoking behaviour among patients with chronic airway disease or respiratory symptoms

Background

This pilot study aimed to investigate the current status of e‐cigarettes (ECs) use patterns among patients with chronic airway disease or chronic respiratory symptoms and the effects of ECs use on respiratory and mental health.

Methods

A cross‐sectional survey was conducted at the outpatient clinic of eight teaching hospitals in South Korea between November 2019 and December 2019. All adult ECs users (19 years and above) who visited the outpatient clinic as a patient with chronic airway disease or chronic respiratory symptoms were eligible to participate in this study.

Results

A total of 51 subjects responded to the survey. Most of the participants were male (92.2%) and the mean age was 41.8 years. Dominant airway diseases were asthma and chronic obstructive pulmonary disease. Most of the subjects had a history of cigarette smoking, and 19 subjects were dual users of current cigarettes and ECs. Most of the subjects started ECs use due to health‐related reasons. When comparing exclusive ECs users and dual users, St. George's respiratory questionnaire (SGRQ) scores, the proportion of cases with moderate to severe depressive symptoms, and average Fagerstrom test for nicotine dependence scores for ECs were higher in dual users than exclusive ECs users (mean 4.64 vs. 2.38, p = 0.006), respectively.

Conclusion

Most of the subjects started ECs use due to health concerns, but dual users have more respiratory symptoms and higher nicotine dependence in this pilot study. One hypothesis that comes from these results is that greater nicotine dependence may influence behaviours, habits, and views about ECs. These preliminary observations need confirmation in a large cohort.

Association between cumulative cigarette and Waterpipe smoking and symptoms of dependence in Lebanese adults

BACKGROUND

Waterpipe and cigarette smoking dependence are becoming increasingly prevalent forms of addiction globally. This study examined whether cumulative cigarette smoking and cumulative waterpipe smoking are associated with higher dependence on both cigarettes and waterpipe.

METHODS

This cross-sectional study conducted between February and April 2020, enrolled 363 participants drawn from all Lebanese districts. The mean age was 29.51 years, 64.8% were females, and 124 (34.2%) exclusive cigarette smokers, 189 (52.1%) exclusive waterpipe smokers, and 50 (13.8%) dual smokers (waterpipe and cigarette). We used the Hooked on Nicotine Checklist (HONC) as an indicator of decreased autonomy towards nicotine, in addition to the Lebanon Waterpipe Dependence Scale-11 (LWDS11) and the Lebanese Cigarette Dependence scale (LCD). A stepwise linear regression was performed taking the HONC scores due to cigarette and waterpipe smoking, LCD and LWDS-11 scores as dependent variables.

RESULTS

The results showed that in the total sample, higher cumulative cigarette smoking (B = 0.005 with a confidence interval of 0.004, 0.006) was significantly associated with higher HONC cigarette scores, whereas higher cumulative waterpipe smoking (B = -0.006 with a confidence interval of - 0.009, - 0.002) was significantly associated with lower HONC cigarette scores. Moreover, higher cumulative waterpipe smoking (B = 0.012 with a confidence interval of 0.009,0.015) was significantly associated with higher HONC waterpipe scores. The results showed that, in both sexes, higher cumulative cigarette smoking was associated with higher HONC cigarette scores and lower HONC waterpipe scores. Furthermore, higher cumulative waterpipe smoking was significantly associated with higher HONC waterpipe scores in both sexes.

CONCLUSION

Our study supports the fact that heavy nicotine consumption, related to both the increased frequency and smoking duration, can increase the risk of dependence. It raises the need for strategic plans to minimize and discourage the use of nicotine products in Lebanese community settings.

Changes in Biomarkers of Cigarette Smoke Exposure After 6 Days of Switching Exclusively or Partially to Use of the JUUL System with Two Nicotine Concentrations: A Randomized Controlled Confinement Study in Adult Smokers

Introduction

Evidence suggests that cigarette smokers who switch to electronic nicotine delivery systems (ENDS) reduce their exposure to harmful toxicants and carcinogens. It is unclear if dual-use is associated with decreases in exposure to toxicants.

Methods

This parallel-group confinement study assessed changes in biomarkers of exposure (BOEs) over six days among healthy adult smokers who were randomized into 1 of 11 study groups: eight JUUL-brand System (JUUL) groups (4 JUUL flavors [Virginia Tobacco, Menthol, Mint, Mango] × 2 nicotine concentrations [5.0% or 3.0% by weight]); Dual-Use group used preferred JUUL flavor (5.0% nicotine) and ≤50% usual brand (UB) cigarettes/day; UB Cigarette group and one group abstained from all tobacco/nicotine product use (Abstinence group). Urine and blood analysis assessed changes in primary BOE endpoints (NNAL, 3-HPMA, MHBMA, S-PMA COHb) and secondary BOE endpoints (NNN, HMPMA, CEMA, 1-OHP, O-toluidine, 2-NA, 4-ABP) among 279 adult smokers.

Results

In JUUL groups, median percent reductions in primary BOEs (Day 6–Baseline) were 90%–≥100% of Abstinence; there were no significant differences between JUUL groups and Abstinence. All reductions in JUUL groups were substantially and statistically significantly greater than reductions in the UB Cigarette group (ps < 0.025). Median reductions in primary BOEs in the Dual-Use group were 43%–55% of Abstinence. Similar results were observed for secondary BOEs.

Conclusion

This study suggests that the use of JUUL as a complete or partial substitute (i.e., dual-use with ≥50% reduction in cigarette consumption) for combustible cigarettes can substantially reduce exposure to multiple toxins associated with cigarette smoking.

Implications

This study adds to the growing body of evidence supporting the utility of ENDS products as potentially reduced-harm alternatives to cigarettes for adult smokers. Adult smokers who switched completely from cigarette smoking to use of the JUUL System (“JUUL”) in two nicotine concentrations (5.0% and 3.0%) and four flavors significantly reduced their exposure to multiple classes of cigarette-related toxicants. Additionally, smokers who used JUUL and continued smoking but reduced their daily cigarette consumption by ≥50% (dual users) also significantly reduced their toxicant exposure compared to cigarette smoking.

Exposure to Nicotine and Toxicants Among Dual Users of Tobacco Cigarettes and E-Cigarettes: Population Assessment of Tobacco and Health (PATH) Study, 2013-2014

INTRODUCTION

Concurrent use of tobacco cigarettes and e-cigarettes ("dual use") is common among tobacco users. Little is known about differences in demographics and toxicant exposure among subsets of dual users.

AIMS AND METHODS

We analyzed data from adult dual users (current every/some day users of tobacco cigarettes and e-cigarettes, n = 792) included in the PATH Study Wave 1 (2013-2014) and provided urine samples. Samples were analyzed for biomarkers of exposure to nicotine and selected toxicants (tobacco-specific nitrosamine NNK [NNAL], lead, cadmium, naphthalene [2-naphthol], pyrene [1-hydroxypyrene], acrylonitrile [CYMA], acrolein [CEMA], and acrylamide [AAMA]). Subsets of dual users were compared on demographic, behavioral, and biomarker measures to exclusive cigarette smokers (n = 2411) and exclusive e-cigarette users (n = 247).

RESULTS

Most dual users were predominant cigarette smokers (70%), followed by daily dual users (13%), non-daily concurrent dual users (10%), and predominant vapers (7%). Dual users who smoked daily showed significantly higher biomarker concentrations compared with those who did not smoke daily. Patterns of e-cigarette use had little effect on toxicant exposure. Dual users with high toxicant exposure were generally older, female, and smoked more cigarettes per day. Dual users who had low levels of biomarkers of exposure were generally younger, male, and smoked non-daily.

CONCLUSIONS

In 2013-2014, most dual users smoked cigarettes daily and used e-cigarettes occasionally. Cigarette smoking appears to be the primary driver of toxicant exposure among dual users, with little-to-no effect of e-cigarette use on biomarker levels. Results reinforce the need for dual users to stop smoking tobacco cigarettes to reduce toxicant exposure.

IMPLICATIONS

With considerable dual use of tobacco cigarettes and e-cigarettes in the United States, it is important to understand differences in toxicant exposure among subsets of dual users, and how these differences align with user demographics. Findings suggest most dual users smoke daily and use e-cigarettes intermittently. Low exposure to toxicants was most common among younger users, males, and intermittent smokers; high exposure to toxicants was most common among older users, females, and heavier cigarette smokers. Results underscore the heterogeneity occurring within dual users, and the need to quit smoking cigarettes completely in order to reduce toxicant exposure.

Harm reduction associated with dual use of cigarettes and e-cigarettes in Black and Latino smokers: Secondary analyses from a randomized controlled e-cigarette switching trial

INTRODUCTION

Most adult cigarette smokers who use e-cigarettes are dual cigarette and e-cigarette (CC-EC) users, yet little is known about relative consumption of cigarettes to e-cigarettes and any associated harm reduction.

METHODS

Rate of substitution from cigarettes to e-cigarettes at week 6 and change in biomarkers of exposure and potential harm were examined among dual CC-EC users [64/114 (56%); 35 Black, 29 Latino] in an e-cigarette switching randomized trial.

RESULTS

Dual users averaged 79% substitution of cigarettes for e-cigarettes at week 6, resulting in a reduction from baseline of 70.0 ± 54.1 cigarettes per week (p < .001). Total nicotine consumption remained stable (baseline: 1160.5 ± 1042.1 pg/mL of cotinine, week 6: 1312.5 ± 1725.9 pg/mL of cotinine, p = .47), while significant reductions were seen in the potent lung carcinogen 4-(methylnitrosamino)-1-(3-pyridul)-1-butanol (NNAL) (-55.9 ± 88.6 ng/ml, p < .001), carbon monoxide (-6.3 ± 8.6 ppm, p < .001), and self-reported respiratory symptoms (-3.3 ± 8.0, p = .002). No significant changes were found in blood pressure or spirometry. Greater substitution from cigarettes to e-cigarettes was associated with larger reductions in NNAL (r = -.29, p = .02).

CONCLUSIONS

The predominant dual use pattern was characterized by regular e-cigarette and intermittent cigarette use. Findings demonstrate the short-term harm reduction potential of this dual use pattern in Black and Latino smokers and suggest that the greatest benefit, aside from cessation of both products, is achieved by higher substitution of e-cigarettes for cigarettes. Findings need confirmation in a larger sample with longer follow-up in dual users with greater variability in rate of substitution.

Association of electronic cigarette exposure with serum uric acid level and hyperuricemia: 2016-2017 Korea National Health and Nutritional Examination Survey

OBJECTIVES

The present study evaluated the association of electronic cigarette (EC) exposure with serum uric acid (UA) level and hyperuricemia (HUA) using a nationally representative sample of South Korea.

METHODS

This study included 10,692 participants (9,905, 609, and 178, never, ever, and current EC users, respectively). Urinary cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) levels were used to determine conventional smoking exposure among EC users. The association between EC use and UA level was evaluated by linear regression analysis. Multivariable logistic regression analysis was used to assess the association between EC and HUA. Subgroup analysis confined to cotinine-verified active smokers was performed to address the association between the dual use of EC and combustible cigarettes and serum UA levels.

RESULTS

The serum UA level was highest among current EC users, followed by ever and never EC users. The prevalence of HUA was 26.2%, 19.3%, and 10.8% in current, ever, and never EC users, respectively. Although EC exposure was positively associated with HUA in a dose-dependent manner only in men (Ptrend = 0.04), a similar tendency was also observed in women with marginal significance (Ptrend = 0.102). The positive association of HUA with EC exposure was more apparent among dual users (odds ratio [OR] = 1.96, 95% confidence interval [CI]: 1.29-2.99) than among those who only smoked combustible cigarettes.

CONCLUSIONS

EC exposure was associated with higher serum UA level and higher OR of HUA. The positive association between EC exposure and HUA was more prominent in dual users who concurrently consumed EC and combustible cigarettes.

The association between short-term emotion dynamics and cigarette dependence: A comprehensive examination of dynamic measures

BACKGROUND

The association between short-term emotion dynamics and long-term psychopathology has been well established in the psychology literature. Yet, dynamic measures for inertia and instability of negative and positive affect have not been studied in terms of their association with cigarette dependence. This study builds an important bridge between the psychology and substance use literatures by introducing these novel measures and conducting a comprehensive examination of such association with intervention implications.

METHODS

This study conducted secondary analysis on the data from a community sample of 136 dual users (e-cigarette + cigarette) and 101 exclusive smokers who completed both the two-week ecological momentary assessment (EMA) and cigarette dependence assessments in a recent study.

RESULTS

Among dual users, a higher average level of negative affect, lower inertia of negative affect (i.e., less sustained negative affect), and higher instability of positive affect (i.e., greater magnitude of changes in positive affect) were associated with higher cigarette dependence. The patterns of associations among exclusive smokers were, however, different. Higher inertia of negative affect, lower instability of positive affect, and higher variability of negative affect were associated with higher dependence.

CONCLUSIONS

The results illustrate the importance of examining not only negative affect but also positive affect in order to fully understand the association between emotion dynamics and cigarette dependence. The different patterns of association between emotion dynamics and cigarette dependence across the two groups of cigarette users also call for future research that is designed to compare cigarettes and e-cigarettes in terms of their effects on emotion regulation.

No evidence of differences in smoking levels, nicotine dependence, carbon monoxide or motivational indices between cigarette smokers and cigarette + e-cigarette dual users in two samples

Concurrent use of electronic cigarettes (e-cigarettes) as an alternative source of nicotine may lead to lower smoke exposure, tobacco addiction and reinforcing value of conventional combustible cigarettes. In two different cohorts, we characterized smokers, dual cigarette/e-cigarette users, and e-cigarette-only users in terms of sociodemographic, motives and patterns of e-cigarette use. Differences in smoking-related characteristics and reinforcing value of cigarettes between smokers and e-cigarette dual users were also examined. Two cohorts comprising 339 community adults [Sample 1; aged 18-65] and 293 young adult binge drinkers [Sample 2; aged 19-24] were recruited in Hamilton, Ontario. All participants provided expired carbon monoxide (CO) samples and completed an assessment battery including the Fagerström Test of Nicotine Dependence (FTND), the Wisconsin Inventory of Smoking Dependence Motives (WISDM), and the Cigarette Purchase Task (CPT). In both samples, smoking rate, CO level, FTND, WISDM, and CPT responses did not significantly differ between smokers and dual users. Compared to e-cigarette-only individuals, dual users from the two cohorts reported a greater use of e-cigarettes for quitting smoking, but dual product consumers exhibited no significant differences in motivation for change relative to combustible-only smokers. Relative to smokers, e-cigarette dual users did not show lower levels of smoking, lower severity of cigarette addiction and reinforcing value of cigarettes in these samples. These findings suggest that concurrent e-cigarette use does not affect combustible tobacco use or motivation, or reduce its harms.

A comparison of product dependence among cigarette only, ENDS only, and dual users: Findings from Wave 3 (2015-2016) of the PATH study

INTRODUCTION

Little is known about differences in tobacco product dependence among people who use two tobacco products versus one. Self-reported product dependence among individuals using cigarettes only, electronic nicotine delivery systems (ENDS) only, and both cigarettes and ENDS (dual users) was compared.

METHOD

PATH Wave 3 data were collected between 2015 and 2016. We used 11 Wisconsin Inventory of Smoking Dependence Motives items to assess cigarette and ENDS dependence, averaged to generate Cigarette Dependence (CD) and ENDS Dependence (ED) scores. Linear regression models were used to assess the association between tobacco use groups and the two dependence scores.

RESULTS

Our analytic sample included 5538 (91.5 %) cigarette only, 399 (6.7 %) ENDS only, and 108 (1.8 %) dual users. There was no difference in CD between cigarette only and dual users. ENDS only users' ED (2.11, SE = 0.05) was higher than dual users' ED (1.67, SE = 0.04) (p < 0.05). Dual users' mean ED (1.70, SE = 0.09) was significantly lower than their CD (3.03, SE = 0.11) (p < 0.001), and ENDS only users' ED (2.34, SE = 0.05) was significantly lower than cigarette only users' CD (2.94, SE = 0.02) (p < 0.001).

CONCLUSION

While there was no difference in CD between dual and cigarette only users, dual users' ED was lower than that for ENDS only users. ENDS appeared to produce less dependence than cigarettes among dual users. Given the high nicotine concentration ENDS products that entered the market after PATH Wave 3 data were collected, future research should examine ED among ENDS only and dual users.

Effect of Pod e-Cigarettes vs Cigarettes on Carcinogen Exposure Among African American and Latinx Smokers: A Randomized Clinical Trial

Importance

Fourth-generation nicotine salt pod system (NSPS) electronic cigarettes (e-cigarettes) are the leading class of e-cigarettes. They contain high nicotine concentrations, which may facilitate switching among smokers, but could also lead to increased exposure to nicotine and biomarkers of potential harm. African American and Latinx smokers experience significant tobacco-related health disparities. The potential of NSPS e-cigarettes to reduce smoking-related harm among these groups is unknown.

Objective

To compare the harm reduction potential of NSPS e-cigarette vs combustible cigarettes.

Design, Setting, and Participants

This unblinded randomized clinical trial compared 6 weeks of e-cigarette use vs cigarettes as usual from to 2018 to 2019 among smokers in the San Diego, California, and Kansas City, Missouri, areas. Participants included African American and Latinx adult combustible cigarette smokers who smoked at least 5 cigarettes/d on at least 25 of the past 30 days for at least 6 months and were interested in switching to e-cigarettes. Data were analyzed from September 18, 2019, to September 4, 2020.

Interventions

6 weeks of e-cigarette use in a choice of pod flavors (5% nicotine) along with brief education, training, and action planning to completely switch to e-cigarettes from combustible cigarettes. The control group smoked combustible cigarettes as usual.

Main Outcomes and Measures

The primary outcome was reduction in urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) concentration at week 6. Secondary outcomes were change in urinary cotinine, expired carbon monoxide (CO), respiratory symptoms, lung function, blood pressure, past 7-day consumption of combustible cigarettes, and switching rates (e-cigarette group only) at weeks 2 and 6.

Results

This study included 186 participants, including 92 African American participants and 94 Latinx participants. The mean (SD) age was 43.3 (12.5) years, and 75 (40.3%) were women. Participants smoked a mean (SD) of 12.1 (7.2) cigarettes/d on 6.8 (0.6) d/wk at baseline. A total of 125 participants were randomized to the e-cigarette group and 61 were randomized to the control group. At baseline, median (interquartile range) NNAL was 124 (45-197) pg/mL in the e-cigarette group and 88 (58-197) pg/mL in the control group. At week 6, the e-cigarette group had significantly greater reductions in NNAL (relative risk [RR], 0.36 [95% CI, 0.23-0.54]; P < .001), CO (RR, 0.53 [95% CI, 0.42-0.68]; P < .001), respiratory symptoms (RR, 0.63 [95% CI, 0.47-0.85]; P = .002), and number of cigarettes smoked in the past 7 days among those still smoking (RR, 0.30 [95% CI, 0.20-0.43]; P < .001) than the control group and maintained their cotinine levels (RR, 0.80 [95% CI, 0.58-1.10]; P = .17). Lung function and diastolic and systolic blood pressure remained unchanged and did not differ between groups. For participants randomized to receive e-cigarettes, 32 participants (28.1%) were exclusively using e-cigarettes at week 6, while 66 participants (57.9%) were dual using and 16 participants (14%) resumed exclusively using cigarettes.

Conclusions and Relevance

These findings suggest that e-cigarettes may be an inclusive harm reduction strategy for African American and Latinx smokers.

Trial Registration

ClinicalTrials.gov Identifier: NCT03511001.

Electronic cigarette dependence and demand among pod mod users as a function of smoking status

Electronic cigarette (e-cigarette) use continues to proliferate with fast-paced product evolution. Pod mod e-cigarettes emerged in the market in 2015 and have changed the tobacco landscape again. However, little is known regarding their addiction potential among users. The current study describes e-cigarette dependence and demand among pod mod users as a function of smoking status (current smokers/dual users, former smokers, and never smokers). Participants were 593 young adult (Mage = 25.9 years) JUUL users recruited via Amazon's Mechanical Turk. Respondents were specifically recruited based on current use of pod mods (but may also be using other e-cigarette devices) and smoking status (never, former, and current/dual users). Participants completed online measures assessing e-cigarette dependence and demand. Dual users of pod mods and cigarettes displayed greater e-cigarette dependence compared to current pod mod users with no history of cigarette smoking (p = .033). Similarly, dual users showed the greatest levels of e-cigarette demand compared to both former smokers and those without a history of smoking (ps < .05). Dual users displayed the greatest e-cigarette dependence and demand. Future research should directly assess potential mechanisms for this effect and continue to monitor e-cigarette dependence as the tobacco landscape changes with the emergence of new e-cigarette products and innovations. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The Acute Effects of Electronic Cigarette Vaping and Tobacco Cigarette Smoking on Choroidal Thickness in Young, Healthy, Habitual, Dual Smokers

The present study aims to evaluate and compare the acute effects of tobacco cigarettes (TC) smoking and electronic cigarette (EC) vaping on foveal and choroidal thickness (CT) in young, healthy, dual smokers. Participants underwent four trials: 5 min TC; 5 min EC; 30 min EC; and 60 min nothing (sham trial). Scans before and immediately after each trial were obtained using spectral domain optical coherence tomography with the enhanced depth imaging mode. Changes in central foveal thickness (CFT), subfoveal choroidal thickness (SFCT), and CT at fourother points, 500 μm and 1000 μm temporally and nasally to the fovea, were measured. Forty-seven participants (33 male, 14 female; mean age 24.85 ± 1.57 years) were included. They smoked 13.53 ± 5.27 TCs/day for 6 ± 2.3 years and vaped ECs for the past 2.4 ± 1.08 years. We did not observe any statistically significant change in SFCT, CFT, and CT of the other points after any of the fourtrials. The acute changes in CFT and CT after EC vaping or TC smoking did not differ significantly compared to the sham trial. Smoking and vaping does not seem to result in statistically significant acute alterations in foveal and CT in young, dual smokers.

Exposure to nicotine-free and flavor-free e-cigarette vapors modifies the pulmonary response to tobacco cigarette smoke in female mice

Most of electronic cigarette (e-cigarette) users are also smoking tobacco cigarettes. Because of the relative novelty of this habit, very little is known on the impact of vaping on pulmonary health, even less on the potential interactions of dual e-cigarette and tobacco cigarette use. Therefore, we used well-established mouse models to investigate the impact of dual exposure to e-cigarette vapors and tobacco cigarette smoke on lung homeostasis. Groups of female BALB/c mice were exposed to room air, tobacco smoke only, nicotine-free flavor-free e-cigarette vapors only or both tobacco smoke and e-cigarette vapors. Moreover, since tobacco smoke and electronic cigarette vapors both affect circadian processes in the lungs, groups of mice were euthanized at two different time points during the day. We found that dual-exposed mice had altered lung circadian gene expression compared with mice exposed to tobacco smoke alone. Dual-exposed mice also had different frequencies of dendritic cells, macrophages, and neutrophils in the lung tissue compared with mice exposed to tobacco smoke alone, an observation also valid for B-lymphocytes and CD4+ and CD8+ T lymphocytes. Exposure to e-cigarette vapors also impacted the levels of immunoglobulins in the bronchoalveolar lavage and serum. Finally, e-cigarette and dual exposures increased airway resistance compared with mice exposed to room air or tobacco smoke alone, respectively. Taken together, these data suggest that e-cigarette vapors, even without nicotine or flavors, could affect how the lungs react to tobacco cigarette smoke exposure in dual users, potentially altering the pathological course triggered by smoking.

Twenty-four-hour subjective and pharmacological effects of ad-libitum electronic and combustible cigarette use among dual users

BACKGROUND AND AIMS

Relative pharmacological effects of e-cigarettes and cigarettes during 24 hours of ad-libitum use have not been described. In this study, 24-hour blood plasma nicotine concentrations and 48-hour subjective effects with use of cigarettes and e-cigarettes were measured among dual users.

DESIGN

Two-arm within-subject cross-over design with preferred e-cigarette or cigarette ad-libitum use over 48 hours.

SETTING

Hospital research ward in San Francisco, California, USA.

PARTICIPANTS

Thirty-six healthy dual users of e-cigarettes and cigarettes (n = 8, 25% females).

MEASUREMENTS

Twenty-four-hour blood plasma nicotine and cotinine concentrations and 48-hour self-reported nicotine withdrawal symptoms and rewarding effects.

FINDINGS

Analyses used analysis of variance (ANOVA)-based mixed models with order of product (e-cigarette or cigarette) and product type (combustible cigarette or type of e-cigarette) as fixed effects, and subject as a repeated effect. During a 24-hour period, e-cigarettes produced lower nicotine exposure than cigarettes for the majority of users, although 25% received more nicotine from e-cigarettes, which was predicted by more frequent e-cigarette use or greater dependence. Compared to cigarette smoking, nicotine exposure for variable-power tank users was similar, while cig-a-like (t₍₃₀₎  = 2.71, P = 0.011, d = 0.745) and fixed-power tank users (t₍₃₀₎  = 3.37, P = 0.002, d = 0.993) were exposed to less nicotine. Cigarettes were rated higher than e-cigarettes on some desirable subjective effects (e.g. psychological reward, t₍₃₂₂₎  = 7.24 P < 0.001, d = 0.432), but withdrawal symptom reduction was comparable. No differences were found between e-cigarette types, but Bayes factors indicate that these measures were insensitive.

CONCLUSIONS

During a 24-hour period in a hospital setting in the United States, nicotine exposure for dual users of e-cigarettes and cigarettes was similar when using cigarettes or variable-power tank devices only but was lower for those using cig-a-like or fixed-power devices only. Despite lower nicotine levels, all types of e-cigarette were effective in preventing withdrawal symptoms. E-cigarettes were rated less rewarding than cigarettes.

Associations Between Self-Reported and Biological Measures of Nicotine Consumption Among Young Adult Nondaily Cigarette Smokers

BACKGROUND AND OBJECTIVES

Intermittent, dual use of cigarettes and e-cigarettes is a common pattern among youth and young adults. However, little is known about the validity of self-report measures of nicotine consumption in these populations. The goal of the present study was to examine associations between self-reported frequency of cigarette and e-cigarette use and nicotine levels in hair samples at two assessments 1 year apart.

METHODS

Participants (n = 90; 65% female) were 19- to 25-year-old intermittent cigarette smokers recruited from the community for a longitudinal study of tobacco use. They submitted hair samples via mail, 1 and 2 years after enrollment in the parent study.

RESULTS

Findings indicated that days of use of both cigarettes and e-cigarettes in the past 30 days independently predicted hair nicotine in the full sample, and when examining only timepoints at which any cigarette use was reported. Timepoints when any e-cigarette use was reported, hair nicotine was positively associated with e-cigarette but not cigarette frequency.

DISCUSSION AND CONCLUSIONS

Data suggest that self-report measures are valid methods of assessing intermittent use of both cigarettes and e-cigarettes. Findings also suggest that dual users may tend to consume more nicotine and thus be at greater risk for dependence than single product users.

SCIENTIFIC SIGNIFICANCE

These results are among the first to indicate that hair analysis can be used to detect intermittent nicotine exposure via both cigarettes and e-cigarettes. (Am J Addict 2020;29:471-475).