Nicotine levels, withdrawal symptoms, and smoking reduction success in real world use: A comparison of cigarette smokers and dual users of both cigarettes and E-cigarettes

Reasons for using e-cigarettes among adults who smoke: comparing the findings from the 2016 and 2020 ITC Korea Surveys

INTRODUCTION

Dual use of e-cigarettes and cigarettes is a growing usage pattern in adults, but little is known about the motivations underlying this trend. We investigated the reasons for e-cigarette use among adults who smoke, considering variation in sociodemographic subgroups.

METHODS

This repeated cross-sectional study analysed adults who smoked at least weekly and vaped at any frequency. Data were from the International Tobacco Control Korea Surveys conducted in 2016 (n=164) and 2020 (n=1088). Fourteen reasons for e-cigarette use were assessed in both waves. Subgroup analyses were performed by age, sex and educational level.

RESULTS

The top reasons for e-cigarette use in 2020 were curiosity (62.8%), less harmful than smoking (45.4%) and taste (43.2%). Curiosity was the most cited across age, sex and education subgroups. Significant differences were observed in 2020 compared with 2016, with lower percentages in goal-oriented reasons: helping quit smoking (36.3% vs 48.9%; p=0.017), helping cut down smoking (35.3% vs 52.7%; p=0.001), less harmful to others (39.0% vs 54.6%; p=0.003) and more acceptable (31.6% vs 61.2%; p<0.001). By contrast, non-goal-oriented reasons showed higher percentages in 2020, such as curiosity (62.8% vs 27.9%; p<0.001), taste (43.2% vs 22.1%; p<0.001) and enjoyment (26.8% vs 8.6%; p<0.001). In 2020, a majority of adults who smoked and vaped (53.3%) reported no intention to quit or reduce smoking.

CONCLUSIONS

E-cigarette use for curiosity and pleasure predominated among adults who smoked. The reasons for dual use in adults have shifted from goal-oriented to non-goal-oriented.

Relative Efficacy of an Acceptance and Commitment Therapy-Based Smartphone App with a Standard US Clinical Practice Guidelines-Based App for Smoking Cessation in Dual Users of Combustible and Electronic Cigarettes: Secondary Findings from a Randomized Trial

BACKGROUND

While smartphone apps for smoking cessation have shown promise for combustible cigarette smoking cessation, their efficacy in helping dual users of combustible and electronic cigarettes (e-cigarettes) to quit cigarettes remains unknown. This study utilized data from a randomized trial to determine if an Acceptance and Commitment Therapy (ACT)-based app (iCanQuit) was more efficacious than a US Clinical Practice Guidelines-based app (QuitGuide) for combustible cigarette smoking cessation among 575 dual users.

METHODS

The primary cessation outcome was self-reported, complete-case 30-day abstinence from combustible cigarettes at 12 months. Logistic regression assessed the interaction between dual use and treatment arm on the primary outcome in the full trial sample (N = 2,415). We then compared the primary outcome between arms among dual users (iCanQuit: n = 297; QuitGuide: n = 178). Mediation analyses were conducted to explore mechanisms of action of the intervention: acceptance of cues to smoke and app engagement. Results: There was an interaction between dual use of combustible and e-cigarettes and treatment arm on the primary outcome (p = 0.001). Among dual users, 12-month abstinence from cigarettes did not differ between arms (23% for iCanQuit vs. 27% for QuitGuide, p = 0.40). Mediation analysis revealed a significant positive indirect effect of the iCanQuit app on 12-month abstinence from cigarettes through acceptance of emotions that cue smoking (p = 0.004).

CONCLUSIONS

Findings from this study of dual users of combustible and e-cigarettes showed no evidence of a difference in quit rates between arms. Acceptance of emotions that cue smoking is a potential mechanism contributing to cigarette smoking abstinence among dual users.

Pain interference among adult dual combustible and electronic tobacco users in terms of perceived barriers for quitting

Electronic cigarette (e-cigarette) use has become increasingly common among combustible cigarette users, and dual use may represent a more severe type of nicotine addiction. Experiencing pain is one prevalent domain that may be important to understand quit processes and behavior among dual users. Although most past research on pain and nicotine/tobacco has focused on combustible cigarette use, initial work on e-cigarette users has found that greater pain severity is associated with higher levels of dependence and negative thinking patterns about e-cigarette use. Yet, there has been no effort to explore the experience of pain among dual users in terms of perceived barriers for quitting combustibles or e-cigarettes. The present study sought to examine pain interference among dual combustible and e-cigarette users in terms of perceived barriers for quitting among 138 (45.9% female; Mage = 35.96 years, SD = 7.16) adult dual users (i.e., users of both combustible cigarette and e-cigarettes). Hierarchical linear regression models indicated that pain interference was significantly associated with both perceived barriers for cessation of combustible cigarettes and perceived barriers for cessation of e-cigarettes. Overall, the present investigation served as an initial evaluation of the role of pain interference in terms of perceived barriers for quitting combustible and e-cigarettes among adult daily dual users. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Psychosocial predictors of trajectories of dual cigarette and e-cigarette use among young adults in the US

INTRODUCTION

Young adults have the highest prevalence of cigarette and e-cigarette use, warranting research to identify psychosocial correlates of their use trajectories.

METHODS

Repeated measures latent profile analyses (RMLPAs) examined past 6-month cigarette and e-cigarette trajectories across 5 waves of data (2018-2020) among 3,006 young adults (Mage = 24.56 [SD = 4.72], 54.8% female, 31.6% sexual minority, 60.2% racial/ethnic minority). Multinomial logistic regression models examined associations among psychosocial factors (i.e., depressive symptoms, adverse childhood experiences [ACEs], personality traits) and trajectories of cigarette and e-cigarette use, controlling for sociodemographics and past 6-month alcohol and cannabis use.

RESULTS

RMLPAs yielded a 6-profile solution, which were uniquely associated with predictors: stable low-level or nonusers of cigarettes and e-cigarettes (66.3%; referent group), stable low-level cigarette and high-level e-cigarette use (12.3%; greater depressive symptoms, ACEs, openness; male, White, cannabis use), stable mid-level cigarette and low-level e-cigarette use (6.2%; greater depressive symptoms, ACEs, extraversion; less openness, conscientiousness; older age, male, Black or Hispanic, cannabis use), stable low-level cigarette and decreasing e-cigarette use (6.0%; greater depressive symptoms, ACEs, openness; younger age, cannabis use), stable high-level cigarette and low-level e-cigarette use (4.7%; greater depressive symptoms, ACEs, extraversion; older age, cannabis use), and decreasing high-level cigarette and stable high-level e-cigarette use (4.5%; greater depressive symptoms, ACEs, extraversion, less conscientiousness; older age, cannabis use).

CONCLUSIONS

Cigarette and e-cigarette prevention and cessation efforts should be targeted both toward specific trajectories of use and their unique psychosocial correlates.

A new statistical model for longitudinal ecological momentary assessment data on dual use of electronic and combustible cigarettes

Background: Existing studies of dual use of electronic and combustible cigarettes either collected longitudinal data with long gaps in between waves or conducted ecological momentary assessment (EMA) over a short period of time. In recent years, the measurement burst design that embeds an EMA protocol in each wave assessment of a traditional longitudinal study has become more popular and yet conventional generalized linear mixed models (GLMM) have important limitations for handling data from this design.Objectives: This study proposed a new statistical method to analyze data from the measurement burst design.Methods: This new statistical method was designed to model the short-term (within-wave) as well as long-term (between-wave) changes and was validated by a simulation study. Secondary analysis was conducted to analyze data from 205 dual users (52% male) and 146 exclusive smokers (50% male) who participated in a recent study using the measurement burst design.Results: The simulation study shows that the proposed method can handle the gap between waves well and is also robust to nonlinear changes across waves. Although no short-term change in smoking was found, dual users reported a long-term reduction in cigarette use that was more rapid compared to exclusive smokers (β ˆ = - 0.0127 , p = .0167 ). Vaping more was associated with smoking less (β ˆ = - 0.0058 , p = .0054 ).Conclusion: The proposed method is highly applicable as it can be easily implemented by substance use researchers and the results can be straightforwardly interpreted. The results suggest that e-cigarette use may play a role in promoting a long-term reduction in smoking among dual users.

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.

The role of electronic cigarette use for quitting or reducing combustible cigarette use in the 30s: Longitudinal changes and moderated relationships

BACKGROUND

Evidence for use of electronic cigarettes (e-cigs) as a potential aid in quitting or reducing combustible cigarette (c-cig) use is mixed. This study examined the extent to which e-cig initiation among smokers in their 30 s predicted quitting or reducing smoking or nicotine dependence symptoms by age 39, and whether the role of e-cigs in quitting differed by prospectively assessed moderators.

METHODS

Data were from the Seattle Social Development Project (SSDP), a panel study of 808 diverse participants with high retention. A subsample of 221 smokers at age 33 was selected for analysis. Self-reports of c-cig use and dependence were assessed longitudinally at ages 33 and 39. Sixteen potential moderators were examined, including social demographics, smoking attitudes and desire to quit, other health behaviors and status, and adolescent and early adult assessments of smoking history.

RESULTS

The use of e-cigs was consistently associated with a lower likelihood of quitting c-cigs by age 39, after accounting for frequency of prior c-cig use at age 33. This negative association persisted across all moderators examined, although it was nonsignificant among those with a definite desire to cut down. Among those who did not quit smoking, e-cig use had no association with decreases in either quantity of c-cigs used or dependence symptoms.

CONCLUSIONS

Results indicate that e-cigarette use was not helpful for quitting or reducing combustible cigarette use in the 30 s. Rather, across extensive tests of moderation, e-cig initiation consistently predicted less quitting during this important age period for successful cessation.

Perception and Behavior about Electric Cigarette in Electric Cigarette Users in Medan City, Indonesia

BACKGROUND: As a new device and technology, the use of e-cigarettes has increased rapidly in Indonesia, e-cigarettes attract and make people curious. AIM: This study aims to determine the description of perceptions and behavior about e- cigarettes in e-cigarette users in Medan city, Indonesia. METHODS: This type of research is quantitative with descriptive design. The sample of this study was 100 electric cigarette users in Medan city, Indonesia, using consecutive sampling method. The data in this study were obtained through a questionnaire conducted in August–October 2019. RESULTS: The respondents of this study were 100 electric cigarette users, consisting of 92 men and 8 women, aged between 17 and 39 years and 42% worked as students. Some respondents had more than 1 electric cigarette device and used different atomizers on different devices. As many as, 42% of tobacco smoking respondents switched to e-cigarettes and stopped smoking. There is a decrease in the number of tobacco cigarette consumption among users who use tobacco cigarettes and electric cigarettes, respondents who had a positive perception of e-cigarettes were 51%, and most of respondents (88%) use e-cigarettes because they see the people around them. CONCLUSION: This study shows that the majority of e-cigarette users in Medan city, Indonesia, are former smokers and have a positive perception of e-cigarettes. Moreover, the most frequent reasons to start using electric cigarette are because they see others around them use it.

The inflammatory biomarker YKL-40 is elevated in the serum, but not the sputum, of E-cigarette users

METHODS

We conducted a cross-sectional study of adults between 18 and 55 years old. Inclusion criteria were: exclusive e-cigarette use or cigarette smoking for ≥ 1 year or no history of tobacco use. Participants with a history of pulmonary illness, atopy, medications (except birth control pills), marijuana, and illegal substance use were excluded. Custom Multiplex ELISA was used to measure YKL-40 and other biomarker levels in the serum and induced sputum of the participants. Multivariable linear regression was used to compare the levels of YLK-40 in healthy participants, e-cigarette, and cigarette users after adjusting for age, sex, and BMI.

RESULTS

We recruited 20 healthy controls, 23 cigarette smokers, and 22 exclusive e-cigarette users. Serum YKL-40 (ng/ml) was significantly higher in e-cigarette users (Median 21.2 [IQR 12.1-24.0] ng/ml) when compared to controls (12.2 [IQR 8.7-18.1] ng/ml, p = 0.016) but comparable to cigarette smokers (21.6 [IQR 11.62-51.7] ng/ml, p = 0.31). No significant differences were found in the serum or sputum of the other biomarkers tested.

CONCLUSION

The inflammatory biomarker, YKL-40 is elevated in the serum but not the sputum of e-cigarette users with no reported pulmonary disease. Further research is necessary to characterize this association.

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.

A Longitudinal Analysis of Nicotine Dependence and Transitions From Dual Use of Cigarettes and Electronic Cigarettes: Evidence From Waves 1-3 of the PATH Study

OBJECTIVE

Electronic cigarettes (e-cigarettes) have gained popularity as a method to reduce conventional cigarette smoking, despite mixed evidence on their effectiveness. This study evaluates the relationship between overall and product-specific nicotine dependence and the transitions between dual use of cigarettes and e-cigarettes versus exclusive cigarette or e-cigarette use over time.

METHOD

This study used data from Waves 1-3 (2013-2016) of the Population Assessment of Tobacco and Health (PATH) Study. Weighted logistic regressions with person-level random effects tested relationships between nicotine dependence and dual versus exclusive use over time. Dual use transitions were then compared with the characteristics of e-cigarette devices used and reasons to use them.

RESULTS

Higher tobacco dependence was associated with becoming or remaining a dual user rather than remaining or becoming an exclusive user of cigarettes or e-cigarettes (p < .05). Higher e-cigarette dependence was associated with remaining or becoming an exclusive e-cigarette user. The number of days smoking cigarettes or using e-cigarettes in the past 30 days was also associated with greater odds of remaining or transitioning to exclusive use of that product (p < .05). Exclusive e-cigarette users tended to invest more financially in their devices and were more likely to report owning modifiable devices.

CONCLUSIONS

This study provides new evidence that established dual use and transitions to and from dual use are associated with higher tobacco dependence compared with remaining a cigarette- or e-cigarette-only user and that higher e-cigarette dependence is associated with becoming or remaining an exclusive user of e-cigarettes.

A Longitudinal Analysis of Nicotine Dependence and Transitions From Dual Use of Cigarettes and Electronic Cigarettes: Evidence From Waves 1-3 of the PATH Study

OBJECTIVE

Electronic cigarettes (e-cigarettes) have gained popularity as a method to reduce conventional cigarette smoking, despite mixed evidence on their effectiveness. This study evaluates the relationship between overall and product-specific nicotine dependence and the transitions between dual use of cigarettes and e-cigarettes versus exclusive cigarette or e-cigarette use over time.

METHOD

This study used data from Waves 1-3 (2013-2016) of the Population Assessment of Tobacco and Health (PATH) Study. Weighted logistic regressions with person-level random effects tested relationships between nicotine dependence and dual versus exclusive use over time. Dual use transitions were then compared with the characteristics of e-cigarette devices used and reasons to use them.

RESULTS

Higher tobacco dependence was associated with becoming or remaining a dual user rather than remaining or becoming an exclusive user of cigarettes or e-cigarettes (p < .05). Higher e-cigarette dependence was associated with remaining or becoming an exclusive e-cigarette user. The number of days smoking cigarettes or using e-cigarettes in the past 30 days was also associated with greater odds of remaining or transitioning to exclusive use of that product (p < .05). Exclusive e-cigarette users tended to invest more financially in their devices and were more likely to report owning modifiable devices.

CONCLUSIONS

This study provides new evidence that established dual use and transitions to and from dual use are associated with higher tobacco dependence compared with remaining a cigarette- or e-cigarette-only user and that higher e-cigarette dependence is associated with becoming or remaining an exclusive user of e-cigarettes.

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.

Changes in Use Patterns Over 1 Year Among Smokers and Dual Users of Combustible and Electronic Cigarettes

BACKGROUND

Dual use of combustible and electronic cigarettes (e-cigarettes) is a growing use pattern; more than half of e-cigarette users are dual users. However, little is known regarding the course of dual use; for example, the likelihood of discontinuation of either combustible or e-cigarettes or both.

METHODS

Adult daily smokers and dual users (daily smokers who also vaped at least once per week) who did not intend to quit use of either product in the next 30 days participated in a longitudinal, observational study (N = 322, 51.2% women, 62.7% white, mean age = 42.27 [SD = 14.05]). At baseline, participants completed demographics and smoking and vaping history assessments. They also reported daily cigarette and e-cigarette use via timeline follow-back assessment and provided a breath sample for carbon monoxide assay at 4-month intervals for 1 year.

RESULTS

Of those who completed the year 1 follow-up, 1.9% baseline smokers and 8.0% dual users achieved biochemically confirmed seven-day point-prevalence abstinence from combustible cigarettes (χ2 = 4.57, p = .03). Of initial dual users, by 1 year 43.9% were smoking only, 48.8% continued dual use, 5.9% were vaping only, and 1.4% abstained from both products. Among baseline smokers, 92.3% continued as exclusive smokers. Baseline dual users who continued e-cigarette use were more likely to be white and report higher baseline e-cigarette dependence.

CONCLUSIONS

In this community sample, the majority of dual users transitioned to exclusive smoking. A higher percentage of dual users quit smoking than smokers, but attrition and baseline differences between the groups compromise strong conclusions. Sustained e-cigarette use was related to baseline e-cigarette dependence.

IMPLICATIONS

This research suggests that dual use of combustible and e-cigarettes is not a sustained pattern for the majority of dual users, but it is more likely to be a continued pattern if the user is more dependent on e-cigarettes. There was evidence that dual users were more likely to quit smoking than exclusive smokers, but this may be due to factors other than their dual use.

Differences in nicotine intake and effects from electronic and combustible cigarettes among dual users

AIM

To describe systemic nicotine exposure and subjective effects of electronic cigarettes (e-cigarettes) in people who use both e-cigarettes and cigarettes (dual users), including within-subject comparisons of e-cigarette and cigarette use.

DESIGN

Two-arm, counterbalanced cross-over study. Participants used their usual brand of e-cigarette or cigarette during a standardized session in a 2-week study.

SETTING

Hospital research ward, San Francisco, CA, USA.

PARTICIPANTS

Thirty-six healthy (eight women, 28 men) participants.

MEASUREMENTS

Plasma nicotine was analyzed by gas chromatography-tandem mass spectrometry; nicotine withdrawal, urge to smoke and vape, affective states, craving, satisfaction and psychological reward were measured by standardized questionnaires.

FINDINGS

Compared with cigarettes, average maximum plasma nicotine concentration (C_max ) was lower with e-cigarettes [6.1 ± 5.5 ng/ml, mean ± standard deviation (SD) versus 20.2 ± 11.1 ng/ml, P < 0.001] and time of maximal concentration (T_max ) was longer (6.5 ± 5.4 versus 2.7 ± 2.4 minutes, P < 0.001). Use of both products resulted in a reduction in the severity of withdrawal symptoms, negative affect and urge to use either product. E-cigarettes were less rewarding and satisfying and reduced craving to a lesser degree than cigarettes. We were not able to detect any differences in withdrawal symptoms, affective states and urge to smoke cigarettes between e-cigarette and cigarette use.

CONCLUSION

Systemic nicotine exposure was, on average, lower with single use of e-cigarettes compared with cigarettes, and e-cigarettes were judged to be less satisfying and rewarding and reduced craving less than cigarettes.

Patterns and trends of dual use of e-cigarettes and cigarettes among U.S. adults, 2015-2018

•

Prevalence of current e-cigarette use among smokers remained relatively stable from 2015 (29.8%) to 2018 (27.7%).

•

Prevalence of current e-cigarette use among never and former smokers increased significantly.

•

Among e-cigarettes users, prevalence of current cigarette smoking decreased from 56.9% (2015) to 40.8% (2018).

•

Approximately 1 in 5 smokers with no plan to quit smoking were current e-cigarette users from 2015 to 2018.

•

About 3 in 10 heavy smokers who were dual users frequently used e-cigarettes from 2015 to 2018.

Introduction

If dual use of cigarettes and e-cigarettes is a transition state to tobacco and nicotine use cessation, it may be a tolerable temporary condition. But, if a long-term behavior, dual use may increase tobacco harm to the population as a whole, and efforts should aim to reduce it as much as possible. To develop effective tobacco control policy, the changes in dual use of e-cigarettes and cigarettes need to be better understood.

Methods

National probability samples of U.S. adults in 2015 (n = 6051), 2016 (n = 6014), 2017 (n = 5992), and 2018 (n = 5989) reported their smoking and e-cigarette use status, including frequency of use. Weighted multinomial logistic regression models were used to examine temporal trends and patterns of cigarette and e-cigarette use.

Results

Between 2015 and 2018, the prevalence of current e-cigarette use (29.8% in 2015, 22.3% in 2016, 29.1% in 2017, and 27.7% in 2018) did not change significantly among current smokers. This result was consistent among light, moderate, and heavy smokers, and did not change when stratified by sex, age and race. However, the prevalence of cigarette smoking in current e-cigarette users declined from 56.9% in 2015 to 40.8% in 2018 (p < 0.001). Among never (p = .012) and former (ps < 0.001) smokers the prevalence of current e-cigarette use increased significantly.

Conclusion

The continued high prevalence of dual use and increased prevalence of current e-cigarette use among never smokers highlight the need for better communication about the risks of prolonged dual use for e-cigarette users, and the risks of nicotine initiation and addiction for nonusers.

Technology-based contingency management and e-cigarettes during the initial weeks of a smoking quit attempt

Contingency management (CM) interventions are among the most effective behavioral interventions for smoking. This study assessed the effects of CM and electronic cigarettes (ECs) on smoking reductions and abstinence for durations of 30-36 days. Twelve participants were exposed to Baseline, EC alone, and EC + CM conditions. An internet-based platform was used to monitor smoking via breath carbon monoxide (CO) and deliver CM for smoking abstinence (CO ≤4 ppm). A Bluetooth-enabled EC monitored daily EC puffs. Abstinence rates were equivalent between EC (34.4%) and EC + CM (30.4%) conditions. Both conditions promoted smoking reductions. We observed an inverse correlation between smoking and EC puffs (r = -.62, p < .05). Results suggest the use of electronic cigarettes can promote smoking reductions and abstinence, and CM did not improve these outcomes. Larger magnitude consequences or tailoring EC characteristics (e.g., flavor) may have improved outcomes. Technology-based methods to collect intensive, longitudinal measures of smoking and electronic cigarette use may be useful to characterize their environmental determinants.

The Role of Nicotine Dependence in E-Cigarettes' Potential for Smoking Reduction

Introduction

E-cigarettes (Electronic Nicotine Delivery Systems, or ENDS) are an increasingly popular tobacco product among youth. Some evidence suggests that e-cigarettes may be effective for harm reduction and smoking cessation, although these claims remain controversial. Little is known about how nicotine dependence may contribute to e-cigarettes' effectiveness in reducing or quitting conventional smoking.

Methods

A cohort of young adults were surveyed over 4 years (approximately ages 19-23). Varying-coefficient models (VCMs) were used to examine the relationship between e-cigarette use and conventional smoking frequency, and how this relationship varies across users with different nicotine dependence levels.

Results

Lifetime, but not recent, e-cigarette use was associated with less frequent concurrent smoking of conventional cigarettes among those with high levels of nicotine dependence. However, nondependent e-cigarette users smoked conventional cigarettes slightly more frequently than those who had never used e-cigarettes. Nearly half of ever e-cigarette users reported using them to quit smoking at the last measurement wave. For those who used e-cigarettes in a cessation attempt, the frequency of e-cigarette use was not associated with reductions in future conventional smoking frequency.

Conclusions

These findings offer possible support that e-cigarettes may act as a smoking reduction method among highly nicotine-dependent young adult cigarette smokers. However, the opposite was found in non-dependent smokers, suggesting that e-cigarette use should be discouraged among novice tobacco users. Additionally, although a substantial proportion of young adults used e-cigarettes to help them quit smoking, these self-initiated quit attempts with e-cigarettes were not associated with future smoking reduction or cessation.

Implications

This study offers potential support for e-cigarettes as a smoking reduction tool among highly nicotine-dependent young adult conventional smokers, although the extent and nature of this remains unclear. The use of e-cigarettes as a quit aid was not associated with reductions in conventional smoking, consistent with most other quit aids in this sample except for nicotine replacement therapy, which was only effective for the most dependent smokers. Notably, these findings highlight the necessity of accounting for smokers' nicotine dependence levels when examining tobacco use patterns.

Dual Versus Never Use of E-Cigarettes Among American Indians Who Smoke

INTRODUCTION

Many American Indian communities have a high prevalence of smoking and e-cigarette use, but factors associated with their dual use are rarely studied.

METHODS

In 2016, a total of 375 American Indian adults who smoke completed paper surveys regarding cigarette and e-cigarette use and provided saliva for cotinine levels. In 2018, cross-sectional analyses were performed, comparing dual users (12%), defined as using e-cigarettes on some or every day for the past 30 days, with never users of e-cigarettes (37%).

RESULTS

Compared with never users, dual users were younger, more often reported history of depression (56% and 29%, respectively; p<0.01) and family history of smoking-related disease (77% and 59%, respectively; p<0.05), had lower harm perceptions of e-cigarettes (27% and 47%, respectively; p<0.01) or vapor (14% and 35%, respectively; p<0.01), and more often perceived e-cigarettes as cessation aids (75% and 16%, respectively; p<0.01) and as less harmful than cigarettes (70% and 17%, respectively; p<0.01). Dual users were less often uncertain/unknowing about e-cigarette benefits or harms (p<0.01) and more often reported likelihood to quit smoking (49% and 24%, respectively; p<0.01) and prior attempt to quit smoking, ever (89% and 67%, respectively; p<0.01) or in the past year (55% and 32%, respectively; p=0.01). Cigarette consumption and cotinine levels did not differ between groups. Dual users more often tried other nicotine products (p<0.02) and more often lived with a vaping partner/spouse (45% and 6%, respectively; p<0.01).

CONCLUSIONS

Dual users perceived e-cigarettes as less harmful than cigarettes and more as cessation aids than cigarette-only users did, but cigarette consumption did not differ between groups. Whether e-cigarettes will reduce smoking-related disparities among American Indian people remains undetermined.

New and Emerging Tobacco Products and the Nicotine Endgame: The Role of Robust Regulation and Comprehensive Tobacco Control and Prevention: A Presidential Advisory From the American Heart Association

The advent of new tobacco products such as electronic cigarettes and the dramatic rise in their use, especially by adolescents and young adults, are significant public health concerns. Electronic cigarettes have become the most popular tobacco products for youth and adolescents in the United States and are attracting youth to new avenues for nicotine addiction. Although these products may have benefit by helping some smokers quit or to move to a less harmful product, the long-term health effects of these products and the net public health effect associated with their use remain unclear and widely debated. There is increasing concern that the use of newer tobacco products may catalyze transition to the use of other tobacco products or recreational drugs, particularly in young adults. Therefore, there is urgent need for robust US Food and Drug Administration regulation of all tobacco products to avoid the significant economic and population health consequences of continued tobacco use. Although the American Heart Association acknowledges that the ultimate endgame would be an end to all tobacco and nicotine addiction in the United States, it supports first minimizing the use of all combustible tobacco products while ensuring that other products do not addict the next generation of youth and adolescents. The endgame strategy needs to be coordinated with the long-standing, evidence-based tobacco control strategies that have significantly reduced tobacco use and initiation in the United States.

Measuring characteristics of e-cigarette consumption among college students

Objective: E-cigarette use among college students has increased drastically in recent years. This study aims to inform development of a comprehensive measure of e-cigarette consumption for this population. Participants and Methods: This mixed-method study collected both quantitative and qualitative data from a sample of 43 experienced e-cigarette users from two college campuses, using a self-reported questionnaire and a semi-structured interview, in March-September of 2017. Results: College student users found some of the consumption questions in national surveys difficult to answer. Switching nicotine levels, mixing flavors, co-using with alcohol and marijuana, using with others who were vaping or drinking, and vaping in a car or indoor space were all common. The participants defined "regular user" based on ownership of a device rather than on quantity/frequency. Conclusions: A comprehensive e-cigarette consumption measure should cover the complex characteristics that are potentially associated with negative health consequences such as flavorings, co-use and social contexts.

Prevalence and Correlates of Electronic Cigarette Use Among a Clinical Sample of Polysubstance Users in Kentucky: Long Live the Cigarette?

BACKGROUND

E-cigarette use has increased in the US, yet, in some regions rates of cigarette use remain high.

PURPOSE

To describe the prevalence and features of lifetime and past-year e-cigarette use among a clinical sample of polysubstance users in Kentucky, and to determine significant associations of past-year e-cigarette use.

RESULTS

Of the final sample (N  =  497), 83.5% reported having ever used e-cigarettes and 97.2% reported having ever used cigarettes. These rates surpass those found among Kentucky's general population. Compared to those who did not report e-cigarette use, e-cigarette users were more likely to be younger ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mo>¯</mml:mo></mml:mover></mml:math> = 33.4 vs. 43.6, p<.001) and White (88.2.1% vs. 62.5%, p = .001). E-cigarette users showed higher rates for lifetime incarceration (91.1% vs. 72.8%, p = .001) and past-year arrest (75.0% vs. 47.5%, p = .001). This group also presented with more severe substance use history and lower mean age for illicit drug use initiation ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mo>¯</mml:mo></mml:mover></mml:math> = 13.8 vs. 16.4, p  =  .001). Approximately 65% of the sample reported past-year e-cigarette use and 96.6% reported past-year cigarette use. Logistic regression indicated that being younger (AOR = .973, p = .030), White (AOR = 1.92, .046), having a past-year arrest (AOR = 1.73, p = .047) and having used cigarettes (AOR = 8.93, p = .001) or kratom (AOR = 3.04, p = .025) within the past year were significantly associated with past-year e-cigarette use.

CONCLUSIONS

E-cigarette use was related to more severe drug-using patterns. Rates of dual tobacco use among this sample are high, particularly among younger individuals. In ecological contexts where cigarette use remains normative, it is likely that dual use will persist for nicotine-dependent, polysubstance-using individuals.

The association between e-cigarette use characteristics and combustible cigarette consumption and dependence symptoms: Results from a national longitudinal study

BACKGROUND

Existing longitudinal surveys focused on the association between ever use of e-cigarettes and combustible cigarette consumption, making it difficult to infer what characteristics of e-cigarette use could potentially change combustible cigarette use behavior, which may have long-term health consequences. Although e-cigarettes' efficacy of alleviating dependence symptoms was supported by studies conducted in laboratory settings, whether the results can be translated into symptom reduction in the real world and over time is an open question.

METHODS

This study conducted secondary analysis on the Waves 1-2 data of the Population Assessment of Tobacco and Health (PATH) Study to examine the association between e-cigarette use characteristics (frequency, flavoring, and voltage adjustment) and combustible cigarette use outcomes (frequency, quantity, and symptoms), using the Heckman 2-step selection procedure with the selection bias controlled. The inclusion criteria ensured that we followed an adult cohort of exclusive combustible cigarette users at Wave 1.

RESULTS

The result shows that higher frequency of e-cigarette use was associated with lower combustible cigarette consumption and dependence symptoms, controlling for the corresponding baseline cigarette use variable and other confounders. Given the frequency of e-cigarette use, the feature of voltage adjustment was not significantly associated with any of the cigarette use outcomes. Flavoring, on the other hand, was associated with lower quantity of cigarette use.

CONCLUSIONS

Exclusive smokers who start using e-cigarettes do indeed change the frequency and quantity with which they smoke cigarettes. E-cigarette use may also help reduce dependence symptoms.

How do we determine the impact of e-cigarettes on cigarette smoking cessation or reduction? Review and recommendations for answering the research question with scientific rigor

AIMS

To propose a hierarchy of methodological criteria to consider when determining whether a study provides sufficient information to answer the question of whether e-cigarettes can facilitate cigarette smoking cessation or reduction.

DESIGN

A PubMed search to 1 February 2017 was conducted of all studies related to e-cigarettes and smoking cessation or reduction.

SETTINGS

Australia, Europe, Iran, Korea, New Zealand and the United States.

PARTICIPANTS AND STUDIES

91 articles.

MEASUREMENTS

Coders organized studies according to six proposed methodological criteria: (1) examines outcome of interest (cigarette abstinence or reduction), (2) assesses e-cigarette use for cessation as exposure of interest, (3) employs appropriate control/comparison groups, (4) ensures that measurement of exposure precedes the outcome, (5) evaluates dose and duration of the exposure and (6) evaluates the type and quality of the e-cigarette used.

FINDINGS

Twenty-four papers did not examine the outcomes of interest. Forty did not assess the specific reason for e-cigarette use as an exposure of interest. Twenty papers did not employ prospective study designs with appropriate comparison groups. The few observational studies meeting some of the criteria (duration, type, use for cessation) triangulated with findings from three randomized trials to suggest that e-cigarettes can help adult smokers quit or reduce cigarette smoking.

CONCLUSIONS

Only a small proportion of studies seeking to address the effect of e-cigarettes on smoking cessation or reduction meet a set of proposed quality standards. Those that do are consistent with randomized controlled trial evidence in suggesting that e-cigarettes can help with smoking cessation or reduction.

An Online Survey of New Zealand Vapers

Using electronic cigarettes (vaping) is controversial, but is increasingly widespread. This paper reports the results of an electronic survey of vapers in New Zealand, a country where the sale and supply of e-liquids containing nicotine is illegal, although vapers can legally access e-liquids from overseas. An on-line survey was conducted, using vaper and smoking cessation networks for recruitment, with follow up surveys conducted 1 and 2 months after the initial survey. 218 participants were recruited. Almost all had been smokers, but three quarters no longer smoked, with the remainder having significantly reduced their tobacco use. Three participants were non-smokers before starting to vape, but none had gone on to become smokers. The overriding motivation to begin and continue vaping was to stop or to reduce smoking. The results were consistent with a progression from initially both vaping and smoking using less effective electronic cigarette types, then moving to more powerful devices, experimentation with flavors and nicotine strengths—all resulting in reducing or stopping tobacco use. Lack of access to nicotine and lack of support for their chosen cessation method were the main problems reported. Vaping had resulted in effective smoking cessation for the majority of participants.

E-cigarettes: Impact of E-Liquid Components and Device Characteristics on Nicotine Exposure

BACKGROUND

Electronic cigarette (e-cigarette) use has increased substantially in recent years. While e-cigarettes have been proposed as a potentially effective smoking cessation tool, dualuse in smokers is common and e-cigarettes are widely used by non-smokers, including youth and young-adult non-smokers. Nicotine, the primary addictive component in cigarettes, is present at varying levels in many e-liquids. E-cigarettes may lead to initiation of nicotine use in adult and youth non-smokers, re-initiation of nicotine dependence in ex-smokers or increased severity of nicotine dependence in dual-users of cigarettes and e-cigarettes. As such, there are important clinical and policy implications to understanding factors impacting nicotine exposure from e-cigarettes. However, the broad and rapidly changing range of e-liquid constituents and e-cigarette hardware which could impact nicotine exposure presents a challenge. Recent changes in regulatory oversight of e-cigarettes underscore the importance of synthesizing current knowledge on common factors which may impact nicotine exposure.

METHODS

This review focuses on factors which may impact nicotine exposure by changing e-cigarette use behavior, puff topography, altering the nicotine yield (amount of nicotine exiting the e-cigarette mouth piece including nicotine exhaled as vapor) or more directly by altering nicotine absorption and bioavailability.

RESULTS

Topics reviewed include e-liquid components or characteristics including flavor additives (e.g., menthol), base e-liquid ingredients (propylene glycol, vegetable glycerin), components commonly used to dissolve flavorants (e.g., ethanol), and resulting properties of the e-liquid (e.g., pH), e-cigarette device characteristics (e.g., wattage, temperature, model) and user behavior (e.g., puff topography) which may impact nicotine exposure.

CONCLUSION

E-liquid characteristics and components, e-cigarette hardware and settings, and user behavior can all contribute substantially to nicotine exposure from e-cigarettes.

Assessing the Association Between E-Cigarette Use and Exposure to Social Media in College Students: A Cross-Sectional Study

BACKGROUND

Social media platforms provide an indirect medium for encouraging e-cigarette use between individuals and also serve as a direct marketing tool from e-cigarette brands to potential users. E-cigarette users share information via social media that often contains product details or health-related claims.

OBJECTIVE

Determine whether e-cigarette use is associated with exposure to e-cigarettes on social media in college students.

METHODS

Data from a sample of 258 college students was obtained via a clicker-response questionnaire (90% response rate). Demographic, lifetime and current e-cigarette/cigarette use, and e-cigarette exposure via social media (peer posts or advertisements) were examined. Logistic regression was used to assess the relationship between lifetime and current e-cigarette use and viewing peer posts or advertisements on social media while adjusting for cigarette use and self-posting about e-cigarettes.

RESULTS

Overall, 46% of participants reported lifetime e-cigarette use, 16% current e-cigarette use, and 7% were current dual users of e-cigarettes and cigarettes. There were positive and significant associations between lifetime e-cigarette use and viewing peer posts (aOR = 3.11; 95% CI = 1.25-7.76) as well as advertisements (aOR = 3.01; 95% CI = 1.19-7.65) on e-cigarettes via social media after adjusting for cigarette use. Current e-cigarette use was only significantly associated with viewing peer posts via social media (aOR = 7.58; 95% CI = 1.66-34.6) after adjusting for cigarette use. Conclusions/Importance: Almost half of college students view peer posts and advertisements on e-cigarettes via social media. This exposure is associated with individual e-cigarette use. Continued efforts to examine online e-cigarette content are needed to help future interventions decrease e-cigarette use.

A Review of Pulmonary Toxicity of Electronic Cigarettes in the Context of Smoking: A Focus on Inflammation

The use of electronic cigarettes (e-cigs) is increasing rapidly, but their effects on lung toxicity are largely unknown. Smoking is a well-established cause of lung cancer and respiratory disease, in part through inflammation. It is plausible that e-cig use might affect similar inflammatory pathways. E-cigs are used by some smokers as an aid for quitting or smoking reduction, and by never smokers (e.g., adolescents and young adults). The relative effects for impacting disease risk may differ for these groups. Cell culture and experimental animal data indicate that e-cigs have the potential for inducing inflammation, albeit much less than smoking. Human studies show that e-cig use in smokers is associated with substantial reductions in blood or urinary biomarkers of tobacco toxicants when completely switching and somewhat for dual use. However, the extent to which these biomarkers are surrogates for potential lung toxicity remains unclear. The FDA now has regulatory authority over e-cigs and can regulate product and e-liquid design features, such as nicotine content and delivery, voltage, e-liquid formulations, and flavors. All of these factors may impact pulmonary toxicity. This review summarizes current data on pulmonary inflammation related to both smoking and e-cig use, with a focus on human lung biomarkers. Cancer Epidemiol Biomarkers Prev; 26(8); 1175-91. ©2017 AACR.

Does e-cigarette use predict cigarette escalation? A longitudinal study of young adult non-daily smokers

Recent studies suggest that e-cigarette use among youth may be associated with increased risk of cigarette initiation. The goal of this study was to test the hypothesis that use of e-cigarettes among young adult non-daily cigarette smokers would be associated with increased cigarette consumption. Participants (n=391; 52% male) were 18-24year-old non-daily cigarette smokers recruited from across California. Cigarette and e-cigarette use were assessed online or via mobile phone every three months for one year between March 2015 and December 2016. Longitudinal negative binomial regression models showed that, adjusted for propensity for baseline e-cigarette use, non-daily smokers who reported more frequent use of e-cigarettes upon study entry reported greater quantity and frequency of cigarette smoking at baseline and greater increases in cigarette quantity over 12months than non-daily cigarette only smokers (ps<0.01). During the 12months of assessment, more consistent consumption of e-cigarettes was associated with greater quantity and frequency of cigarette use (ps<0.01); these effects did not vary over time. Findings suggest that among non-daily smokers, young adults who use e-cigarettes tend to smoke more cigarettes and to do so more frequently. Such individuals may be at greater risk for chronic tobacco use and dependence.

Recent updates on electronic cigarette aerosol and inhaled nicotine effects on periodontal and pulmonary tissues

E-cigarette-derived inhaled nicotine may contribute to the pathogenesis of periodontal and pulmonary diseases in particular via lung inflammation, injurious, and dysregulated repair responses. Nicotine is shown to have antiproliferative properties and affects fibroblasts in vitro, which may interfere in tissue myofibroblast differentiation in e-cig users. This will affect the ability to heal wounds by decreasing wound contraction. In periodontics, direct exposure to e-vapor has been shown to produce harmful effects in periodontal ligament and gingival fibroblasts in culture. This is due to the generation of reactive oxygen species/aldehydes/carbonyls from e-cig aerosol, leading to protein carbonylation of extracellular matrix and DNA adducts/damage. A limited number of studies regarding the effects of e-cig in oral and lung health are available. However, no reports are available to directly link the deleterious effects on e-cigs, inhaled nicotine, and flavorings aerosol on periodontal and pulmonary health in particular to identify the risk of oral diseases by e-cigarettes and nicotine aerosols. This mini-review summarizes the recent perspectives on e-cigarettes including inhaled nicotine effects on several pathophysiological events, such as oxidative stress, DNA damage, innate host response, inflammation, cellular senescence, profibrogenic and dysregulated repair, leading to lung remodeling, oral submucous fibrosis, and periodontal diseases.