E-Cigarettes and Adolescents' Risk Status

Longitudinal bidirectional association between youth electronic cigarette use and tobacco cigarette smoking initiation in Thailand

INTRODUCTION

This study quantifies the longitudinal association between e-cigarette use and subsequent conventional cigarette initiation and vice versa among Thai youths.

METHODS

Data from a longitudinal survey of 6045 Thai seventh grade students with baseline in 2019 and the 12-month follow-up in 2020 were analysed using complex survey multivariate logistic regressions to assess whether e-cigarette use was associated with subsequent cigarette smoking (ever, current and dual product users at follow-up) among baseline never smokers.

RESULTS

Consistent with prior findings from other countries, among those who had never smoked cigarettes at baseline, ever e-cigarette users were more likely to try cigarette smoking (adjusted OR 4.44; 95% CI 2.23 to 8.86; p<0.001), or become dual users (adjusted OR 5.31; 95% CI 2.63 to 10.74; p<0.001) 1 year later. Baseline current e-cigarette users were more likely to become ever smokers (adjusted OR 5.37; 95% CI 1.82 to 15.90; p=0.005), current smokers (OR 3.92; 95% CI 1.69 to 9.14; p=0.003) and dual product users (adjusted OR 6.96; 95% CI 1.54 to 31.38; p=0.015) at the 12-month follow-up than non-e-cigarette users. Similarly, among never e-cigarette users at baseline, ever cigarette smoking were more likely to try e-cigarettes (adjusted OR 3.38; 95% CI 1.66 to 6.88; p=0.002), currently use e-cigarettes (adjusted OR 2.75; 95% CI 1.47 to 5.13; p=0.003) and currently use both e-cigarettes and cigarettes (adjusted OR 4.87; 95% CI 2.92 to 8.13; p<0.001) at the follow-up than never smokers. Among never e-cigarette users at baseline, current-cigarette smoking were more likely to try e-cigarettes (adjusted OR 6.21; 95% CI 2.58 to 14.95; p<0.001), currently use e-cigarettes (adjusted OR 2.80; 95% CI 1.27 to 6.14; p=0.014) and currently use both e-cigarettes and cigarettes (adjusted OR 7.70; 95% CI 3.45 to 17.19; p<0.001) at the follow-up than never smokers.

CONCLUSIONS

This longitudinal study in Asian low-income and middle-income countries supports the prospective association of youth e-cigarette use with subsequent smoking initiation and youth cigarette use with subsequent e-cigarette initiation that is similar to that observed in high-income Western countries.

Adolescent electronic cigarette use and tobacco smoking in the Millennium Cohort Study

AIMS

To evaluate the catalyst, diversion and common liability hypotheses by examining associations between e-cigarette use and tobacco cigarette smoking at modal ages 14 and 17 years, controlling for adolescent and infancy risk factors.

DESIGN

Intergenerational, prospective cohort data from the Millennium Cohort Study (MCS). Nationally representative sample of infants born September 2000 to January, 2002.

SETTING

United Kingdom.

PARTICIPANTS

Parent and child data from 10 625 youth assessed in infancy and modal ages 11, 14 and 17 years.

MEASUREMENTS

Age 14 and 17 e-cigarette and combustible cigarette use (recency, frequency). Potential confounders were age 11 risk factors (e.g. alcohol use, externalizing behaviors, parental tobacco use, permissiveness), infancy risk factors (e.g. maternal smoking during pregnancy, smoke exposure in infancy) and demographic characteristics.

FINDINGS

Among youth who had not smoked tobacco by age 14 (n = 9046), logistic regressions estimated that teenagers who used e-cigarettes by age 14 compared with non-e-cigarette users, had more than five times higher odds of initiating tobacco smoking by age 17 [odds ratio (OR) = 5.25, 95% confidence interval (CI) = 3.28-8.38] and nearly triple the odds of being a frequent tobacco smoker at age 17 (OR = 2.91, 95% CI = 1.56-5.41), net of risk factors and demographics. Among youth who had not used e-cigarettes by age 14 (n = 9078), teenagers who had smoked tobacco cigarettes by age 14 had three times higher odds of initiating e-cigarettes by age 17 (OR = 2.98, 95% CI = 1.74-5.09) compared with non-tobacco smokers and nearly three times higher odds of frequently using e-cigarettes at age 17 (OR = 2.90, 95% CI = 1.21-6.95), net of confounders. Similar links between e-cigarette and tobacco cigarette use were observed in regressions following coarsened exact matching.

CONCLUSIONS

E-cigarette use by age 14 is associated with increased odds of tobacco cigarette initiation and frequent smoking at age 17 among British youth. Similarly, tobacco smoking at age 14 is associated with increased odds of both e-cigarette initiation and frequent use at age 17.

E-cigarette initiation predicts subsequent academic performance among youth: Results from the PATH Study

Research shows cigarette smoking is associated with lower academic performance among youth. This study examines how initiating e-cigarette use is associated with subsequent academic performance. Data from Waves 2-4 youth and parent surveys of the Population Assessment of Tobacco and Health (PATH) Study were analyzed. Youth (12-15 years old) who reported never using any tobacco products at Wave 2 were included in the analysis (n = 4960). Initiation of e-cigarettes and cigarettes was assessed at Wave 3. Weighted multivariable linear regression models were tested to assess the association between e-cigarette and cigarette initiation at Wave 3 and academic performance at Wave 4, controlling for covariates at Wave 2. At Wave 3, 4.3% and 1.9% of youth initiated e-cigarette and cigarette use, respectively. Youth who initiated e-cigarette use at Wave 3 had lower academic performance at Wave 4, compared to those who did not initiate e-cigarette use (adjusted regression coefficient [ARC] -0.22, 95% confidence interval [CI] -0.43, -0.02). Initiating cigarettes was also associated with lower academic performance (ARC -0.51, 95% CI -0.84, -0.18). Results indicate that e-cigarette use initiation is associated with lower subsequent academic performance, independent from the association between cigarette use initiation and lower academic performance among U.S. youth. Future research needs to examine whether preventing youth e-cigarette and cigarette use can lead to improvement in academic performance.

Waterpipe smoking and subsequent cigarette and e-cigarette use: a cohort study

Aim

We tested the hypothesis that waterpipe smoking increases the likelihood to try conventional and electronic cigarettes.

Methods

In 2017 and 2018, 2752 German adolescents (mean age: 14.9 years), who had never tried conventional cigarettes or e-cigarettes, took part in a longitudinal survey with a 6-month observational period. Multiple regression analyses tested the association between waterpipe use at baseline and first experimentation with e-cigarettes at follow-up. The models adjusted for risk-taking propensity (sensation seeking and experimentation with alcohol and marijuana), age, sex, migration background, type of school and peer substance use.

Results

Some 381 adolescents (12.5% of the survey population) reported waterpipe smoking at baseline. The overall initiation rate during the 6 months was 4.9% (n=134) for conventional cigarettes and 10.5% (n=288) for e-cigarettes. Prior waterpipe smoking significantly predicted cigarette use (adjusted relative risk (ARR)=1.81, 95% CI 1.19-2.76), as well as e-cigarette use (ARR=3.29, 95% CI 2.53-4.28). In addition, a significant interaction between waterpipe use and sensation seeking was found (ARR=0.56, 95% CI 0.33-0.95), with waterpipe use being more predictive of later e-cigarette initiation for lower sensation-seeking individuals.

Discussion

Waterpipe use predicted both later cigarette and e-cigarette use independent of all other assessed risk factors, indicating that waterpipe use might be a risk factor on its own. The results suggest that the association was stronger for adolescents with a lower risk-taking propensity, which brings this group into focus for prevention efforts. However, further research is needed to understand whether these associations are causal.

Peer Crowd Identification of Young and Early Middle Adulthood Customers at Vape Shops

Vape shops specialize in the sales of e-cigarettes and other vaping products. In recent studies, young adults who use e-cigarettes have tended to identify with at-risk peer crowds. This is the first study to examine vape shop customers' clientele. Composed primarily of young adults and persons in early middle adulthood, we speculated that a relatively high prevalence of those who appeared to bystanders as radical/extreme (at-risk) customers would be identified as such at these shops. We recruited vape shops throughout Southern California (N = 44 shops), and trained teams of data collectors visited each of the consented vape shops, making note of 451 customers' appearance, including features such as manner of dress, presence of tattoos, and hairstyles. Customers were then coded as either belonging to a conventional, progressive, or radical/extreme crowd based on outward appearance. Of the customers observed, 223 (49%) were rated as appearing to be in the conventional crowd; 169 (38%) were rated as appearing to be in the progressive crowd, and only 59 (13%) were rated as appearing to be in the radical/extreme crowd. The conventional crowd tended to appear older. Clientele may reflect that more conventional young and early middle age adults are tempted to visit vape shops due to perceptions of greater acceptability or safety of e-cigarettes. E-cigarette mass media campaigns aimed at protecting potential vape shop customers from harm may need to depict more conservative-looking characters.

Electronic Cigarette-Related Injuries Presenting to Five Large Burn Centers, 2015-2019

Electronic cigarettes are advertised as safer alternatives to traditional cigarettes yet cause serious injury. US burn centers have witnessed a rise in both inpatient and outpatient visits to treat thermal injuries related to their use. A multicenter retrospective chart review of American Burn Association burn registry data from 5 large burn centers was performed from January 2015 to July 2019 to identify patients with electronic cigarette-related injuries. A total of 127 patients were identified. Most sustained less than 10% total body surface area burns (mean 3.8%). Sixty-six percent sustained 2nd degree burns. Most patients (78%) were injured while using their device. Eighteen percent of patients reported spontaneous device combustion. Two patients were injured while changing their device battery, and two were injured modifying their device. Three percent were injured by second-hand mechanism. Burn injury was the most common injury pattern (100%), followed by blast injury (3.93%). Flame burns were the most common (70%) type of thermal injury; however, most patients sustained a combination-type injury secondary to multiple burn mechanisms. The most injured body region was the extremities. Silver sulfadiazine was the most common agent used in initial management of thermal injuries. Sixty-three percent of patients did not require surgery. Of the 36% requiring surgery, 43.4% required skin grafting. Multiple surgeries were uncommon. Our data recognizes electronic cigarette use as a public health problem with potential to cause thermal injury and secondary trauma. Most patients are treated on an inpatient basis although most patients treated on outpatient basis have good outcomes.

Electronic Vapor Product Use and Sexual Risk Behaviors in US Adolescents

BACKGROUND AND OBJECTIVES

Adolescent electronic vapor product (EVP) usage continues to increase and is associated with heightened engagement in other risk behaviors. However, there is limited research on associations between youth EVP use and sexual risk behaviors (SRBs). In this study, we examined how current youth EVP and/or cigarette usage, as well as EVP usage frequency, is related to several SRBs.

METHODS

Respondents (N = 12 667) of the 2017 National Youth Risk Behavior Survey were categorized by previous 30-day EVP and/or cigarette usage: nonuse, EVP use only, cigarette use only, or dual use. Separately, respondents were categorized by previous 30-day EVP usage frequency: 0, 1 to 9, 10 to 29, or 30 days. Ten SRBs were identified as dependent variables. Adjusted prevalence ratios were calculated by using modified Poisson regression to determine associations between SRBs and both current EVP and/or cigarette usage and EVP usage frequency. Linear contrasts compared adjusted prevalence ratios across usage and frequency categories.

RESULTS

Youth EVP-only users and dual users were more likely than nonusers to engage in 9 of 10 SRBs. Prevalence proportions did not differ between EVP-only users and dual users for 7 of 10 behaviors. Occasional EVP users were more likely than nonusers to engage in 9 of 10 SRBs and were similarly as likely as frequent and daily users to engage in all 10 SRBs.

CONCLUSIONS

EVP usage among US high school students, with or without concurrent cigarette use, was associated with heightened engagement in several SRBs. Prevalence of engagement in most SRBs did not differ among occasional, frequent, and daily EVP users.

Social Learning, Social Bonds, Self-Control and Adolescent Nicotine Vaping

The aim of this study was to examine whether three theories of adolescent substance use-social learning, social bonding, and self-control-were useful for predicting adolescent nicotine vaping. Methods: The analysis utilized data on U.S. 8th and 10th grade students from the 2017 and 2018 Monitoring the Future (MTF) studies, repeated cross-sectional surveys that included 11,624 youth who responded to questions about past 12-month nicotine vaping. Measures from each of the three theories were used to predict the outcome using a zero-inflated negative binomial model. Results: The results demonstrated that variables from social learning and self-control theories were key predictors of nicotine vaping. Friends' substance use appeared as the most consequential predictor, followed by low self-control or higher risk-taking propensities. An interaction effect also suggested that friends' substance use had a stronger association with nicotine vaping among youth who reported higher self-control. Conclusions/Importance: The findings suggested that adolescent nicotine vaping is a consequence of social learning influences and low self-control. Future research should explore these and similar factors in more detail.

Electronic and Combustible Cigarette Use in Adolescence: Links With Adjustment, Delinquency, and Other Substance Use

PURPOSE

The purpose of the study was to identify proximal links between electronic cigarette (e-cigarette) use and numerous indicators of adjustment, delinquency, and other substance use in adolescence, beyond prior levels and confounders.

METHODS

The ongoing Millennium Cohort Study is a nationally representative, intergenerational, longitudinal study of children born 2000-2001 in the United Kingdom followed from birth to age 14 years (n = 11,564 adolescents and their parents). A series of ordinary least squares and logistic regressions compared 14-year-old e-cigarette only users to never users and to combustible/dual users on 10 measures of adjustment (school engagement, well-being, and self-esteem), delinquency (theft, vandalism, disorderly conduct, and graffitiing), and other substance use (frequent alcohol use, heavy drinking, and marijuana use). Controls included each outcome variable measured at age 11 years and prospectively assessed parent and child confounders (e.g., parent education, child externalizing and internalizing behaviors, cognitive test scores, gender, and race/ethnicity).

RESULTS

At age 14 years, e-cigarette only users (approximately 7% of youth) had a higher risk of adolescent adjustment problems, delinquent behavior, and substance use relative to nonusers (75% of youth), but lower risk relative to combustible cigarette/dual users (18% of youth), even after controlling for a host of childhood confounders.

CONCLUSIONS

Positive links shown here between e-cigarette use and poor adjustment, delinquency, and other substance use in adolescence, coupled with accumulating evidence that e-cigarettes substantially increase youths' likelihood of combustible smoking, indicate that e-cigarettes are part of an emerging pattern of health-risk behaviors and poor adjustment for some youth.

Associations of ADHD Symptoms With Smoking and Alternative Tobacco Product Use Initiation During Adolescence

Objective

Recently, use of alternative tobacco products, such as electronic cigarettes (e-cigarettes) and hookah (water-pipe tobacco), has increased among adolescents. It is unknown whether attention-deficit hyperactivity disorder (ADHD) symptoms are associated with initiation of alternative tobacco product use.

Methods

Ninth grade high school students who never used any tobacco product at baseline (N = 1,921) participated in a longitudinal survey from 2014 to 2015. Overall symptomatology and inattention (IN) and hyperactivity-impulsivity (HI) ADHD subtypes were assessed at baseline. Past 6-month e-cigarette, hookah, and combustible cigarette use (yes/no) were reported at three semi-annual follow-ups. Repeated measures logistic regression models assessed the association of baseline ADHD symptoms with likelihood of tobacco product initiation across follow-ups.

Results

For ADHD main effect estimates, unadjusted odds of reporting e-cigarette, hookah, and combustible cigarette use pooled across follow-up time points were 45%, 33%, and 37% greater, respectively, with each increase in one SD-unit of baseline ADHD symptoms in baseline never-users of tobacco products. ADHD was not associated with hookah or combustible cigarette use after adjusting for other risk factors. After adjustment, e-cigarette use initiation remained associated with overall ADHD (odds ratio, OR [95%confidence interval, 95% CI] = 1.22 [1.04, 1.42]) and HI (OR [95% CI] = 1.26 [1.09, 1.47]) symptoms, but not IN symptoms (OR [95% CI] = 1.13 [0.97, 1.32]). ADHD × Time interactions were not significant, suggesting ADHD increased odds of e-cigarette use initiation but did not alter the shape of use trajectory across follow-up among initiators.

Conclusions

Understanding the psychosocial mechanisms underlying the pathway from ADHD to e-cigarette use may advance tobacco product use etiologic theory and prevention practice in the current era in which e-cigarette use is popular among youth.

Characterizing Polytobacco Use Trajectories and Their Associations With Substance Use and Mental Health Across Mid-Adolescence

Background

Polytobacco product use is suspected to be common, dynamic across time, and increase risk for adverse behavioral outcomes. We statistically modeled characteristic types of polytobacco use trajectories during mid-adolescence and tested their prospective association with substance use and mental health problems.

Methods

Adolescents (N = 3393) in Los Angeles, CA, were surveyed semiannually from 9th to 11th grade. Past 6-month combustible cigarette, e-cigarette, or hookah use (yes/no) over four assessments were analyzed using parallel growth mixture modeling to identify a parsimonious set of polytobacco use trajectories. A tobacco product use trajectory group was used to predict substance use and mental health at the fifth assessment.

Results

Three profiles were identified: (1) tobacco nonusers (N = 2291, 67.5%) with the lowest use prevalence (<3%) of all products across all timepoints; (2) polyproduct users (N = 920, 27.1%) with moderate use prevalence of each product (8–35%) that escalated for combustible cigarettes but decreased for e-cigarettes and hookah across time; and (3) chronic polyproduct users (N = 182, 5.4%) with high prevalence of each product use (38–86%) that escalated for combustible cigarettes and e-cigarettes. Nonusers, polyproduct users, and chronic polyproduct users reported successively higher alcohol, marijuana, and illicit drug use and ADHD at the final follow-up, respectively. Both tobacco using groups (vs. nonusers) reported greater odds of depression and anxiety at the final follow-up but did not differ from each other.

Conclusions

Adolescent polytobacco use may involve a common moderate risk trajectory and a less common high-risk chronic trajectory. Both trajectories predict substance use and mental health symptomology.

Implications

Variation in use and co-use of combustible cigarette, e-cigarette, and hookah use in mid-adolescence can be parsimoniously characterized by a small set common trajectory profiles in which polyproduct use are predominant patterns of tobacco product use, which predict adverse behavioral outcomes. Prevention and policy addressing polytobacco use (relative to single product use) may be optimal tobacco control strategies for youth, which may in turn prevent other forms of substance use and mental health problems.

E-Cigarette Use and Future Cigarette Initiation Among Never Smokers and Relapse Among Former Smokers in the PATH Study

OBJECTIVES

Any potential harm-reduction benefit of electronic cigarettes (e-cigarettes) could be offset by nonsmokers who initiate e-cigarette use and then smoke combustible cigarettes. We examined correlates of e-cigarette use at baseline with combustible cigarette smoking at 1-year follow-up among adult distant former combustible cigarette smokers (ie, quit smoking ≥5 years ago) and never smokers.

METHODS

The Population Assessment of Tobacco and Health Study, a nationally representative, longitudinal study, surveyed 26 446 US adults during 2 waves: 2013-2014 (baseline) and 2014-2015 (1-year follow-up). Participants completed an audio computer-assisted interview in English or Spanish. We compared combustible cigarette smoking at 1-year follow-up by e-cigarette use at baseline among distant former combustible cigarette smokers and never smokers.

RESULTS

Distant former combustible cigarette smokers who reported e-cigarette past 30-day use (9.3%) and ever use (6.7%) were significantly more likely than those who had never used e-cigarettes (1.3%) to have relapsed to current combustible cigarette smoking at follow-up (P < .001). Never smokers who reported e-cigarette past 30-day use (25.6%) and ever use (13.9%) were significantly more likely than those who had never used e-cigarettes (2.1%) to have initiated combustible cigarette smoking (P < .001). Adults who reported past 30-day e-cigarette use (7.0%) and ever e-cigarette use (1.7%) were more likely than those who had never used e-cigarettes (0.3%) to have transitioned from never smokers to current combustible cigarette smokers (P < .001). E-cigarette use predicted combustible cigarette smoking in multivariable analyses controlling for covariates.

CONCLUSIONS

Policies and counseling should consider the increased risk for nonsmokers of future combustible cigarette smoking use as a result of using e-cigarettes and any potential harm-reduction benefits e-cigarettes might bring to current combustible cigarette smokers.

Delay discounting and e-cigarette use: An investigation in current, former, and never cigarette smokers

BACKGROUND

Cigarette smokers show greater delay discounting (devaluation of delayed consequences) than non-smokers, suggesting that rapid devaluation of the future contributes to tobacco use through a mechanism in which tobacco-related health consequences are too delayed to discourage smoking. However, little work has quantified delay discounting in relation to electronic cigarette (EC) use, a tobacco product that many users believe to pose fewer negative health consequences than cigarettes.

METHODS

We assessed discounting of delayed monetary rewards in a web-based sample of 976 participants, stratified by both EC use (current and never) and cigarette use (current, former, and never).

RESULTS

Controlling for demographic variance, current EC users generally showed greater discounting than never EC users (p = .019). Current cigarette smokers also showed greater discounting than former and never smokers (p < .001). However, the between-group difference for EC use was much smaller (η_p² = .006) than for cigarette use (η_p² = .026). Moreover, differences in discounting in relation to EC use were not statistically apparent in most pairwise comparisons. Most notably, the difference between former smokers who achieved smoking cessation by transitioning to ECs (i.e., exclusive EC users) and those who have never used ECs or cigarettes was nonsignificant and small (η_p² = .010).

CONCLUSIONS

The smaller effect size for the association between delay discounting and current EC use, relative to current cigarette use, suggests that public perception of ECs as a safer alternative to cigarettes attenuates the role of delay discounting in decisions to use ECs.

Limited mutagenicity of electronic cigarettes in mouse or human cells in vitro

OBJECTIVES

Electronic cigarettes (e-cig), which are promoted as safe alternatives to tobacco cigarettes or as aides to smoking cessation, are becoming increasingly popular among adult chronic smokers and adolescents experimenting with tobacco products. Despite the known presence of toxicants and carcinogens in e-cig liquid and vapor, the possible carcinogenic effects of e-cig use in humans are unknown.

MATERIALS AND METHODS

We have utilized two validated in vitro model systems to investigate whether e-cig vapor induces mutation in mouse or human cells. We have exposed transgenic mouse fibroblasts in vitro to e-cig vapor extracts prepared from three popular brands, and determined the induction of mutagenesis in a reporter gene, the cII transgene. Furthermore, we have treated the pSP189 plasmid with e-cig vapor extract, transfected human fibroblast cells with the e-cig-treated plasmid, and screened for the induced mutations in the supF gene.

RESULTS AND CONCLUSION

We observed no statistically significant increases in relative mutant frequency in the cII transgene or supF gene in the e-cig treated mouse or human cells, respectively. Our data indicate that e-cig vapor extracts from the selected brands and at concentrations tested in this study have limited mutagenicity in both mouse and human cells in vitro.