Sex Difference in the Association between Electronic Cigarette Use and Subsequent Cigarette Smoking among U.S. Adolescents: Findings from the PATH Study Waves 1-4

A systematic review and meta-analysis of the association between e-cigarette use among non-tobacco users and initiating smoking of combustible cigarettes

INTRODUCTION

The rapid increase in e-cigarette use over the past decade has triggered an important public health question on the potential association between e-cigarette use and combustible cigarette smoking. Following AMSTAR 2 and PRISMA guidelines, this evidence synthesis sought to identify and characterize any associations between e-cigarette use among individuals not smoking cigarettes and initiation of cigarette smoking.

METHODS

The protocol was registered on September 24, 2018 (PROSPERO 2018 CRD42018108540). Three databases were queried from January 01, 2007 to April 26, 2023. Search results were screened using the PICOS review method.

RESULTS

Among 55 included studies (40 "good" and 15 "fair"; evidence grade: "high") that adjusted for gender, age, and race/ethnicity between groups, generally, there was a significant association between non-regular e-cigarette use and initiation of cigarette smoking, further supported by the meta-analytic results (AOR 3.71; 95% CI 2.86-4.81). However, smoking initiation was most often measured as ever/current cigarette smoking. Two studies (quality: 2 "good") evaluated progression to regular cigarette smoking among individuals with regular use of e-cigarettes, and generally found no significant associations. One study ("good") evaluated smoking initiation among individuals with regular use of e-cigarettes, finding an increasing probability of ever smoking cigarettes with increased e-cigarette use. Twelve studies (10 "good" and two "fair") examining progression to regular smoking among individuals with non-regular use of e-cigarettes reported inconsistent findings.

CONCLUSIONS

Numerous methodological flaws in the body of literature limit the generalizability of these results to all individuals who are not smoking cigarettes with few studies measuring established/regular use/smoking of e-cigarettes and cigarettes. Further, studies did not control adequately for specific confounding variables representing common liabilities between e-cigarette use and cigarette smoking, nor did they account for sufficient follow-up durations. Collectively, these flaws limit the generalizability of findings to the question of an association between e-cigarette use and cigarette smoking initiation.

Transitions between smoking and vaping: Evidence (or lack thereof) on potential differences by gender and sex

OBJECTIVE

To synthesize existing evidence on possible differential effects by sex and gender from two Cochrane reviews evaluating vaping and smoking transitions.

METHODS

We screened included studies from two Cochrane reviews for studies reporting smoking outcomes based on gender or sex. The first review examines the effects of using e-cigarettes to help people quit smoking and includes randomized controlled trials and uncontrolled intervention studies published to July 2023. The second review aims to assess the evidence on the relationship between the use and availability of e-cigarettes and subsequent smoking in young people (aged 29 and younger) and includes quasi-experimental and cohort studies published to April 2023. Due to the paucity and heterogeneity of data, we report results narratively.

RESULTS

10 of 161 studies included in the two relevant reviews met our criteria. Only five reported analyzing whether observed effects or associations varied based on sex and/or gender. A further three provided relevant descriptive information, and two did not report overall outcomes regarding vaping and smoking transitions but did investigate whether these differed by sex/gender. Synthesized data were largely inconclusive, but there was some suggestion that vaping was more strongly associated with subsequent smoking in young males than females. No studies reported data on nonbinary participants.

CONCLUSIONS

Despite plausible reasons why sex and gender may be moderators of vaping and smoking transitions, there is little evidence investigating this. Future studies of vaping and smoking transitions should conduct and report analyses investigating potential differences based on sex and gender.

Nicotine pouch marketing strategies in the USA: an analysis of Zyn, On! and Velo

INTRODUCTION

Nicotine pouches are gaining popularity, yet their marketing is understudied.

METHODS

Using Numerator advertising data from January 2019 to September 2021 regarding three popular brands of nicotine pouch in the USA-Zyn (by Swedish Match, introduced in the USA in July 2016), On! (Altria, August 2016) and Velo (RJ Reynolds, July 2019)-we examined (1) general advertising characteristics (eg, media type, year); (2) ad content (ie, headlines and imagery themes); (3) prominent media channels (ie, specific websites, magazines, etc); and (4) ad expenditures.

RESULTS

There were 286 unique ads (Zyn: 44.4%; On!: 2.8%; Velo: 52.8%), 119 143 occurrences (Zyn: 3.5%; On!: 0.5%; Velo: 96.0%) and $24 774 650 total expenditures (Zyn: 4.7%; On!: 0.6%; Velo: 94.7%). The greatest proportion of ad occurrences and expenditures were accounted for by radio (75.9% and 28.2%, respectively) and television (16.2% and 56.5%), followed by mobile (0.5% and 7.2%) and online display (6.7% and 3.6%). Across ad occurrences and expenditures, prominent headline themes included 'freedom' (26.0% and 17.1%, respectively), 'brand' (9.6% and 18.6%) and 'flavour' (16.4% and 7.6%); images mainly featured the product alone (61.4% and 56.1%), text (16.2% and 24.6%) or men (8.7% and 8.6%); and prominent channel themes were entertainment (34.7% and 37.3%), news/weather (14.3% and 21.7%), business/finance (12.9% and 9.0%) and sports (9.5% and 1.0%). Zyn and On! prioritised online display and print; Velo prioritised radio and television. Zyn's and Velo's headlines focused on 'freedom', with Zyn also emphasising 'brand' and Velo 'innovation'; On!'s headlines emphasised 'flavour'.

CONCLUSIONS

Regulatory efforts must be informed by surveillance of nicotine pouch marketing and impacts on consumer subgroups (eg, young people).

School climate and school identification as determinants of smoking conventional cigarettes or vaping among adolescents in China: Stress-coping mediation mechanisms

INTRODUCTION

Smoking conventional cigarettes or vaping (SV) poses significant health threats to adolescents. School climate and school identification are key elements of the school environment and potential factors of SV. Based on the Stress Coping Theory, the mediations between school climate/school identification and SV, via perceived stress/active coping, were examined.

METHODS

A cross-sectional survey was conducted among secondary school students from February to March 2022 in Taizhou, China. Structural equation modeling was used.

RESULTS

The prevalence of SV among the 7526 participants was 4.7% (singular use of conventional cigarettes: 3.2%; singular use of electronic cigarettes: 3.6%; dual use: 2.1%). School climate, school identification, and active coping were positively, and perceived stress (family stress, academic stress, and peer-related stress) were negatively associated with SV. The association between school climate and SV was fully mediated via: 1) school climate → perceived stress → SV; 2) school climate → active coping → SV; and 3) school climate → perceived stress → active coping → SV. The effect sizes were 52.1%, 43.8%, and 6.3%, respectively. Similar partial mediation mechanisms were found between school identification and SV, with relatively small effect sizes (<10%).

CONCLUSIONS

This study observed the prevalence of SV among Chinese secondary school students. School climate and school identification had both significant direct and indirect (via perceived stress/active coping) effects on SV. Positive school environments may reduce students' stress and promote active coping. The stress coping mechanisms explained the association between school climate and SV better than between school identification and SV.

Exposure to e-cigarette advertisements and non-advertising content in relation to use behaviors and perceptions among US and Israeli adults

INTRODUCTION

As e-cigarette marketing strategies diversify, it is important to examine exposure to and impact of e-cigarette advertisements and non-advertising content (e.g. on social media) via multiple media channels among adults in different regulatory contexts.

METHODS

Using 2021 cross-sectional data among 2222 adults in the US (n=1128) and Israel (n=1094), multivariable regression examined past-month e-cigarette advertisement and non-advertising content exposure in relation to past-month e-cigarette use (logistic regression), as well as use intentions and risk perceptions (linear regressions), controlling for sociodemographics and tobacco use.

RESULTS

Overall, 20.3% reported past-month e-cigarette use (15.5% US, 25.2% Israel), 46.1% any advertisement exposure (28.7% digital media, 25.2% traditional media, 16.8% retail settings), and 34.1% any non-advertising exposure (19.4% social media, 13.6% websites, 12.3% movie/television/theater, 5.8% radio/podcasts). Exposure to digital media advertisements (AOR=1.95; 95% CI: 1.42-2.66), traditional media advertisements (AOR=2.00; 95% CI=1.49-2.68), and social media non-advertising (AOR=1.72; 95% CI: 1.25-2.36) correlated with e-cigarette use. Exposure to traditional media advertisements (β=0.23; 95% CI: 0.08-0.38) and social media non-advertising (β=0.26; 95% CI: 0.09-0.43) correlated with use intentions. Exposure to digital media advertisements (β= -0.32; 95% CI: -0.57 - -0.08), retail setting advertisements (β= -0.30; 95% CI: -0.58 - -0.03), and radio/podcast non-advertising (β= -0.44; 95% CI: -0.84 - -0.03) correlated with lower perceived addictiveness. Radio/podcast non-advertising exposure (β= -0.50; 95% CI: -0.84 - -0.16) correlated with lower perceived harm. However, retail setting advertisement exposure was associated with e-cigarette non-use (AOR=0.61; 95% CI: 0.42-0.87), and traditional media advertisement (β=0.38; 95% CI: 0.15-0.61) and social media non-advertising exposure (β=0.40; 95% CI: 0.14-0.66) correlated with greater perceived addictiveness.

CONCLUSIONS

E-cigarette-related promotional content exposure across media platforms impacts perceptions and use, thus warranting regulation.

Sex Differences in E-Cigarette Use and Related Health Effects

BACKGROUND

Electronic cigarettes (e-cigarettes) comprise a variety of products designed to deliver nicotine, flavorings, and other substances. To date, multiple epidemiological and experimental studies have reported a variety of health issues associated with their use, including respiratory toxicity, exacerbation of respiratory conditions, and behavioral and physiological effects. While some of these effects appear to be sex- and/or gender-related, only a portion of the research has been conducted considering these variables. In this review, we sought to summarize the available literature on sex-specific effects and sex and gender differences, including predictors and risk factors, effects on organ systems, and behavioral effects.

METHODS

We searched and selected articles from 2018-2023 that included sex as a variable or reported sex differences on e-cigarette-associated effects.

RESULTS

We found 115 relevant studies published since 2018 that reported sex differences in a variety of outcomes. The main differences reported were related to reasons for initiation, including smoking history, types of devices and flavoring, polysubstance use, physiological responses to nicotine and toxicants in e-liquids, exacerbation of lung disease, and behavioral factors such as anxiety, depression, sexuality, and bullying.

CONCLUSIONS

The available literature supports the notion that both sex and gender influence the susceptibility to the negative effects of e-cigarette use. Future research needs to consider sex and gender variables when addressing e-cigarette toxicity and other health-related consequences.

Consequences of adolescent drug use

Substance use in adolescence is a known risk factor for the development of neuropsychiatric and substance use disorders in adulthood. This is in part due to the fact that critical aspects of brain development occur during adolescence, which can be altered by drug use. Despite concerted efforts to educate youth about the potential negative consequences of substance use, initiation remains common amongst adolescents world-wide. Additionally, though there has been substantial research on the topic, many questions remain about the predictors and the consequences of adolescent drug use. In the following review, we will highlight some of the most recent literature on the neurobiological and behavioral effects of adolescent drug use in rodents, non-human primates, and humans, with a specific focus on alcohol, cannabis, nicotine, and the interactions between these substances. Overall, consumption of these substances during adolescence can produce long-lasting changes across a variety of structures and networks which can have enduring effects on behavior, emotion, and cognition.

First use of cannabis compared to first use of alcohol and tobacco: Associations with single and poly-substance use behavior

INTRODUCTION

Young adults report high rates of current cannabis use. The proliferation of legalized cannabis in the US has led to greater access and availability, causing cannabis to become the new "gateway" drug. This study examined the prevalence of trying cannabis before alcohol or tobacco and the association of initiation with cannabis first with single and poly-substance use in young adults.

METHODS

METHODS: Data were analyzed from young adults (n=8062) in Waves 1 through 5 (2013-2019) of the Population Assessment of Tobacco and Health study who had ever tried alcohol, cannabis, or tobacco and provided age at first use of these substances. Weighted multivariable models examined associations between cannabis initiation before, at the same age, or after initiating alcohol or tobacco use with past 30-day substance use (alcohol, cannabis, tobacco, poly-substance use) in a subsequent wave (Waves 2-5).

RESULTS

Initiating cannabis before alcohol and tobacco (6%) was rare. In adjusted regression models, initiating cannabis before alcohol and tobacco was associated with increased odds of past 30-day cannabis use, past 30-day tobacco use, and past 30-day polysubstance use and decreased odds of past 30-day alcohol use. Initiating cannabis at the same age as either alcohol or tobacco, or trying cannabis after these substances was associated with increased odds of all substance use outcomes.

CONCLUSIONS

Cannabis initiation before alcohol and tobacco is uncommon and may even protect against future alcohol use. Deterring cannabis initiation with multiple substances could have public health benefits.

The Short-Term and Long-Term Associations Between Receiving Tobacco Discounts or Coupons and Smoking Cessation Among U.S. Adult Cigarette Smokers With Intention to Quit

INTRODUCTION

To examine the associations between baseline receipt of cigarette and non-cigarette tobacco discounts or coupons and smoking cessation at follow-up among US adult cigarette smokers with the intention to quit at baseline.

AIMS AND METHODS

Data were from the Population Assessment of Tobacco and Health (PATH) study wave 3 (October 2015-October 2016), wave 4 (December 2016-January 2018), and wave 5 (December 2018-November 2019) surveys. Two separate sets of analyses were conducted using wave 3-4 data (N = 3707) and wave 4-5 data (N = 6251). Specifically, wave 4 was used as the 1-year follow-up of wave 3 to examine the short-term association, and wave 5 was used as the 2-year follow-up of wave 4 to examine the longer-term association. Study population were current established cigarette smokers with the intention to quit (within 1 year for wave 3-4 data) at baseline. Exposure was self-reported past 12-month receipt of discounts or coupons for cigarettes and non-cigarette tobacco products at baseline, and outcome was self-reported completely quitting cigarette smoking at follow-up. Baseline single-wave weights were applied, and multivariate logistic regressions were used to estimate the adjusted associations.

RESULTS

Participants who received cigarette discounts or coupons at baseline were less likely to quit completely for both 1-year follow-up (aOR = 0.66, 95% CI: 0.48 to 0.90) and 2-year follow-up (aOR = 0.74, 95% CI: 0.61 to 0.90). Baseline receipt of discounts or coupons for non-cigarette tobacco products were not consistently associated with cigarette smoking cessation at follow-up.

CONCLUSIONS

Receipt of cigarette discounts or coupons was associated with a reduced likelihood of successful quitting among cigarette smokers with intention to quit. Policies restricting cigarette coupons may help them quit completely.

IMPLICATIONS

This study found that among baseline current established cigarette smokers with intention to quit in the United States, baseline receipt of cigarette discounts or coupons was negatively associated with cigarette smoking cessation for both 1-year follow-up and 2-year follow-up. Baseline receipt of discounts or coupons for e-cigarettes, cigars, and other tobacco products were not consistently significantly associated with cigarette smoking cessation at follow-up. Our study results indicated that policies restricting cigarette coupons may help increase the likelihood of successful smoking cessation for smokers with intention to quit.

Birth Outcomes Associated With E-Cigarette and Non-E-Cigarette Tobacco Product Use During Pregnancy: An Examination of PATH Data Waves 1-5

OBJECTIVES

To examine associations of prenatal e-cigarette use to pregnancy and birth outcomes.

METHODS

Currently pregnant women (n = 1 037) from Waves 1 through 4 of the Population Assessment of Tobacco and Health Study who had pregnancy or live birth outcome data in a subsequent wave (Waves 2-5; 2013 to 2019). Weighted bivariate and multivariable models\ examined associations between past 30-day tobacco use assessed during pregnancy (any past 30-day e-cigarette use, any past 30-day non-e-cigarette tobacco use, or no past 30-day tobacco use) with adverse pregnancy (miscarriage, abortion, ectopic or tubal pregnancy, stillbirth) and birth outcomes (preterm birth, low birth weight, birth defect, placenta previa, placental abruption, pre-eclampsia) reported in the subsequent wave.

RESULTS

Approximately 1% of pregnant women reported past 30-day exclusive e-cigarette use and 3.2% used e-cigarettes and one other tobacco product. Compared to no tobacco use, past 30-day e-cigarette use (exclusive or use with another tobacco product) during pregnancy was not associated with increased odds of an adverse pregnancy or birth outcome in bivariate or multivariable models. Past 30-day non-e-cigarette tobacco use was associated with increased odds of an adverse pregnancy outcome in multivariable models, but not an adverse live birth outcome. Compared to past 30-day cigarette use, past 30-day e-cigarette use during pregnancy was not associated with lowered odds of a birth or pregnancy outcome.

CONCLUSIONS

E-cigarette use during pregnancy is rare. Understanding the positive and negative impacts of pre-natal e-cigarette use on women's health may guide public health messaging campaigns.

IMPLICATIONS

Results showed that past 30-day e-cigarette use during pregnancy was low, with cigarette smoking remaining the most prevalent form of tobacco use during pregnancy. Current e-cigarette use during pregnancy used either exclusively or with another tobacco product, was not associated with increased risk of an adverse pregnancy, or birth outcome. A small sample size of e-cigarette users and limited information on quantity and frequency of e-cigarette use before and during pregnancy may limit conclusions. Healthcare providers may use this information when discussing the harms and consequences associated with e-cigarette and tobacco use during pregnancy.

Predictors of E-cigarette and Cigarette Use Trajectory Classes from Early Adolescence to Emerging Adulthood Across Four Years (2013-2017) of the PATH Study

INTRODUCTION

This study examines predictors of trajectories of cigarette and e-cigarette use among a cohort of US adolescents transitioning into young adulthood. Comparing trajectories of each tobacco product is important to determine if different intervention targets are needed to prevent progression to daily use.

METHODS

Latent trajectory class analyses identified cigarette and e-cigarette use (never, ever excluding past 12-month, past 12-month (excluding past 30-day (P30D)), P30D 1-5 days, P30D 6+ days) trajectory classes, separately, among US youth (12-17; N = 10,086) using the first 4 waves (2013-2017) of data from the nationally representative PATH Study. Weighted descriptive analyses described the class characteristics. Weighted multinomial logistic regression analyses examined demographic, psychosocial, and behavioral predictors of class membership.

RESULTS

Younger adolescents 12-15 years had lower tobacco use compared to 16-17 year olds and less stable classes. In the 16-17 year group, there were five unique trajectories of cigarette smoking, including a Persistent High Frequency class. Four e-cigarette use trajectories were identified; but not a persistent use class. Shared predictors of class membership for cigarettes and e-cigarettes included mental health problems, other tobacco use, marijuana use, and poorer academic achievement. Male sex and household tobacco use were unique e-cigarette trajectory class predictors.

CONCLUSIONS

There was no evidence that initiation with e-cigarettes as the first product tried was associated with cigarette progression (nor cigarettes as first product and e-cigarette progression). Interventions should focus on well-established risk factors such as mental health and other substance use to prevent progression of use for both tobacco products.

IMPLICATIONS

Using nationally representative data and definitions of use that take into account frequency and recency of use, longitudinal 4-year trajectories of e-cigarette and cigarette use among US adolescents transitioning into young adulthood were identified. Results among 16-17-year olds revealed a class of persistent high frequency cigarette smoking that was not identified for e-cigarette use. Cigarette use progression was not associated with e-cigarettes as the first product tried. Risk factors for progression of use of both products included mental health and other substance use, which are important prevention targets for both tobacco products.

Bidirectional associations between depressive symptoms and cigarette, e-cigarette, cannabis, and alcohol use: Cross-lagged panel analyses among young adults before and during COVID-19

BACKGROUND

The literature regarding bidirectional relationships of depressive symptoms to cigarette and alcohol use is mixed, and limited regarding e-cigarette and cannabis use. Moreover, COVID-19 has significantly impacted mental health and substance use, especially among young adults. Thus, this is a critical period for focused research on these relationships among young adults.

METHODS

We analyzed longitudinal data (assessments in Fall 2018, 2019, and 2020) from 3,006 young adults (Mage = 24.56 [SD = 4.72], 54.8% female, 31.6% sexual minority, 71.6% White, 5.3% Black, 12.2% Asian, 11.4% Hispanic) from 6 US metropolitan statistical areas. Cross-lagged panel models were conducted to examine bidirectional associations between depressive symptoms and past 30-day use of cigarettes, e-cigarettes, cannabis, and alcohol (respectively), controlling for sociodemographics.

RESULTS

During the study period, depressive symptoms decreased before the pandemic but increased during, cigarette and e-cigarette use decreased in both periods, alcohol use showed no change before but increases during the pandemic, and cannabis use increased in both periods. Additionally, each outcome demonstrated greater stability before versus during COVID-19. Finally, greater antecedent depressive symptoms correlated with more days of subsequent cigarette (β = 0.03, SE = 0.01, p =.011) and e-cigarette use (β = 0.03, SE = 0.01, p =.021), but fewer days of alcohol use (β = -0.02, SE = 0.01, p =.035). W2 cannabis use and alcohol use, respectively, were related to W3 depressive symptoms (cannabis: β = 0.09, SE = 0.02, p <.001; alcohol: β = 0.06, SE = 0.02, p =.002). No other cross-lagged associations were significant.

CONCLUSIONS

Intervention efforts targeting depression and substance use should explicitly address the potential for onset and escalation of substance use and depressive symptoms, respectively, especially during societal stressors.

Association of e-Cigarette Advertising, Parental Influence, and Peer Influence With US Adolescent e-Cigarette Use

IMPORTANCE

Little is known about the roles of advertising and parental and peer influence in e-cigarette use among US adolescents in recent years, hindering efforts to address the increasing rate of youth vaping.

OBJECTIVE

To examine how e-cigarette advertising exposure and parental and peer e-cigarette use were associated with e-cigarette use among US adolescents.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from waves 4 (December 2016 to January 2018), 4.5 (December 2017 to December 2018), and 5 (December 2018 to November 2019) of the Population Assessment of Tobacco and Health study, an on-going cohort study representative of the noninstitutionalized US population. Sample weights were applied to generate nationally representative estimates. Data were analyzed in January 2022.

EXPOSURES

Past 30-day e-cigarette advertising exposure, past 30-day parental e-cigarette use, and the number of best friends using e-cigarettes (none, a few, some, most, and all).

MAIN OUTCOMES AND MEASURES

Outcomes were contemporary curiosity about using e-cigarettes and e-cigarette initiation at follow-up. Generalized estimating equations were used to estimate the weighted adjusted associations.

RESULTS

Wave 4 included 8548 adolescents; wave 4.5, 10 073 adolescents; and wave 5, 11 641 adolescents. Among adolescents in the wave 4 survey, 4425 (51.1%) were boys, 1935 (24.9%) were aged 12 years, 1105 (13.0%) were Black, 2515 (24.4%) were Hispanic, and 3702 (52.3%) were White. More than 60% of adolescents reported past 30-day e-cigarette advertising exposure at each survey. Among adolescents who had never used e-cigarettes, those who reported e-cigarette advertising exposure were more likely to feel curious about using e-cigarettes (adjusted odds ratio [aOR], 1.56 [95% CI, 1.43-1.70]) and were more likely to become ever e-cigarette users (aOR, 1.21 [95% CI, 1.05-1.41]) and current e-cigarette users (aOR, 1.42 [95% CI, 1.16-1.75]) at follow-up. Adolescents who reported having best friends using e-cigarettes were more likely to feel curious about using e-cigarettes (eg, all best friends: aOR, 4.13 [95% CI, 2.35-7.26]) and initiate e-cigarette use at follow-up (eg, among adolescents reporting all best friends use e-cigarettes, risk of ever use: aOR, 4.08 [95% CI, 1.44-11.59]; risk of current use aOR, 5.42 [95% CI, 1.49-19.72]) than adolescents who reported having no best friends using e-cigarettes.

CONCLUSIONS AND RELEVANCE

This cohort study of US adolescents found that e-cigarette advertising and peer influence were significantly associated with e-cigarette initiation. Efforts to address youth vaping need to consider peer influence and incorporate measures reducing e-cigarette advertising exposure.

Consumption of JUUL vs. Other E-Cigarette Brands among U.S. E-Cigarette Users: Evidence from Wave 5 of the PATH Study

This study examines the use of JUUL vs. other e-cigarette brands among U.S. youth (12-17 years), young adult (18-24 years), and adult (25 years and above) e-cigarette users. Data were from the Population Assessment of Tobacco and Health (PATH) study Wave 5 survey (2019). The study population was past 30-day e-cigarette users who knew the brand of e-cigarettes they usually/last used (N = 2569). JUUL use was reported by 65.2% of youth, 60.7% of young adult, and 25.6% of adult e-cigarette users in our study sample. The share of JUUL consumed in the past 30 days, measured by the total number of puffs, was 15.4% by youth, 55.5% by young adults, and 29.1% by adults. By contrast, the share of other e-cigarettes consumed was 4.2% by youth, 28.9% by young adults, and 66.9% by adults. Youth JUUL users were more likely to use e-cigarettes within 30 min after waking (aOR = 2.30, 95% CI: 1.12-4.75) than youth users of other brands of e-cigarettes. Additionally, youth e-cigarette users who currently smoked cigarettes were less likely to use JUUL (aOR = 0.55, 95% CI: 0.30-0.99). This study concludes that JUUL consumption was disproportionally higher among youth and young adults in the U.S. in 2019.

Longitudinal associations between e-cigarette use and onset of multiple modes of cannabis use among US adolescents

OBJECTIVE

To examine the prospective associations between e-cigarette use and subsequent onset of various modes of cannabis use during a 12-month follow-up period among US adolescents.

METHODS

Data were from the Wave 4 (2017, baseline) and Wave 4.5 (12-month follow-up) surveys of the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative, longitudinal cohort study. Study population was cannabis-naïve US adolescents (12-16 years) at baseline who reported cannabis use status at follow-up (N = 9,692). Outcomes were modality-specific past-12-month cannabis use (vaping, blunting, smoking with hookah) and any cannabis use (past-12-month and past-30-day) at follow-up. Multivariate logistic regressions were used to estimate the weighted association between baseline past-30-day e-cigarette use and each outcome.

RESULTS

Baseline e-cigarette use was significantly associated with onset of cannabis vaping (aOR = 4.00, 95% CI = 2.25-7.10), blunting (aOR = 5.30, 95% CI = 2.82-9.94), any cannabis use (aOR = 3.94, 95% CI = 2.35-6.62), and past-30-day cannabis use (aOR = 4.47, 95%CI = 2.64-7.58) at follow-up. Non-Hispanic blacks were more likely to report past-12-month blunting (aOR = 1.55, 95% CI = 1.07-2.24) and smoking cannabis with hookah (aOR = 3.13, 95% CI = 1.14-8.63) compared with non-Hispanic whites. Other tobacco use, alcohol use, perceiving e-cigarette use as having little or some harm, older age, high severity of externalizing mental health problems, and living in states legalized adult recreational cannabis use were significantly associated with future onset of cannabis vaping, blunting, and any cannabis use.

CONCLUSIONS

The association of e-cigarette use with cannabis vaping was not stronger than its association with other modes of cannabis use. Future studies are needed to explain the mechanisms linking e-cigarettes and cannabis use.

Associations of prenatal exposure to mixtures of organochlorine pesticides and smoking and drinking behaviors in adolescence

It is important to identify the factors that influence the prevalence of disinhibitory behaviors, as tobacco and alcohol use in adolescence is a strong predictor of continued use and substance abuse into adulthood. Organochlorine pesticides (OCPs) are persistent organic pollutants that pose a potential risk to the developing fetus and offspring long-term health. We examined associations between prenatal exposure OCPs and their metabolites (i.e., p,p'-DDT, p,p'-DDE, o,p'-DDT, oxychlordane, and hexachlorobenzene (HCB)), both as a mixture and single compounds, and alcohol consumption and smoking at adolescence in a sample (n = 554) from the Child Health and Development Studies prospective birth cohort. Bayesian Kernel Machine Regression demonstrated a trend of higher risk of alcohol use and smoking with higher quartile mixture levels. Single-component analysis showed increased odds of smoking and drinking with increases in lipid-adjusted p,p'-DDE serum levels (aOR = 2.06, 95% CI 0.99-4.31, p = 0.05, per natural log unit increase). We found significant effect modification in these associations by sex with higher p,p'-DDT serum levels (aOR = 0.26, 95% CI 0.09-0.076, p = 0.01, per natural log unit increase) was associated with lower odds of smoking and drinking in female adolescents, while higher p,p'-DDE serum levels (aOR = 2.98, 95% CI 1.04-8.51, p = 0.04, per natural log unit increase) was associated with higher odds of the outcomes. Results of the mutually adjusted model were not significant for male adolescents. Further research to understand reasons for these sex-differences are warranted.

Effect modification of legalizing recreational cannabis use on the association between e-cigarette use and future cannabis use among US adolescents

BACKGROUND

Many states have legalized recreational cannabis use for adults. However, no study has examined how this policy may interact with youth vaping to influence cannabis use among US adolescents. This study investigates whether the association between baseline e-cigarette use and subsequent cannabis use differs by state recreational cannabis legalization status.

METHODS

This study analyzed data from the first four waves (2013-2018) of the Population Assessment of Tobacco and Health Study, a nationally representative longitudinal survey. The study sample included adolescents (aged 12-17) who reported never used cannabis at baseline. Generalized estimating equations were used to analyze the effect modification of state recreational cannabis law on the association between baseline e-cigarette use and cannabis use at 12-month follow-up, controlling for individual characteristics.

RESULTS

Among adolescents who have never used cannabis at baseline, baseline past-30-day e-cigarette use was significantly associated with past-30-day cannabis use at 12-month follow-up (aOR=5.92, 95% CI: 3.52-9.95). This association was different by state recreational cannabis legalization status, as indicated by the significant interaction term. Subgroup analysis showed that the aOR was 18.39 (95% CI: 4.25-79.68) for adolescents living in states that legalized adult recreational cannabis use and 5.09 (95% CI: 2.86-9.07) for adolescents living in states without such laws.

CONCLUSIONS

E-cigarette use is associated with cannabis initiation among youth. This association is stronger among those living in states that legalized adult recreational cannabis use. Further examination of the impact of e-cigarette use on cannabis initiation in relation to state cannabis laws is warranted.

Role of Mental Health in the Association Between E-Cigarettes and Cannabis Use

INTRODUCTION

E-cigarette use may be associated prospectively with subsequent cannabis use among U.S. adolescents. However, it remains unclear whether this association differs by individual mental health status. This longitudinal study examines effect modifications by mental health status.

METHODS

The first 4 waves (2013-2017) of the Population Assessment of Tobacco and Health study were analyzed in 2020. Adolescents (aged 12-17 years) who reported never using cannabis at baseline waves were included. Waves 1-3 were each considered as baseline for their 12-month follow-up waves. Generalized estimating equations were used to evaluate the effect modification of internalizing mental health and externalizing mental health problems on the associations between baseline past 30-day e-cigarette use and past 30-day cannabis use at follow-up, controlling for individual characteristics and state recreational cannabis laws.

RESULTS

Baseline e-cigarette use was significantly associated with cannabis use at follow-up (AOR=4.81, 95% CI=2.93, 7.90). Adolescents with high severity of internalizing mental health/externalizing mental health problems were significantly more likely to initiate cannabis use. However, current e-cigarette users who reported high severity of internalizing mental health symptoms were less likely to initiate cannabis use (AOR=2.51, 95% CI=0.92, 6.83) than those who reported low severity of internalizing mental health problems (AOR=8.84, 95% CI=4.19, 18.65). There were no differences by the severity of externalizing mental health problems.

CONCLUSIONS

Baseline e-cigarette use and endorsement of severe internalizing mental health/externalizing mental health problems were significantly associated with subsequent cannabis use among U.S. adolescents. Efforts to reduce youth vaping and improve youth mental health could help curb cannabis initiation. Tailored interventions may be warranted for e-cigarette‒using adolescents with internalizing mental health problems.

E-Cigarette Toxicology

Since the spread of tobacco from the Americas hundreds of years ago, tobacco cigarettes and, more recently, alternative tobacco products have become global products of nicotine addiction. Within the evolving alternative tobacco product space, electronic cigarette (e-cigarette) vaping has surpassed conventional cigarette smoking among adolescents and young adults in the United States and beyond. This review describes the experimental and clinical evidence of e-cigarette toxicity and deleterious health effects. Adverse health effects related to e-cigarette aerosols are influenced by several factors, including e-liquid components, physical device factors, chemical changes related to heating, and health of the e-cigarette user (e.g., asthmatic). Federal, state, and local regulations have attempted to govern e-cigarette flavors, manufacturing, distribution, and availability, particularly to underaged youths. However, the evolving e-cigarette landscape continues to impede timely toxicological studies and hinder progress made toward our understanding of the long-term health consequence of e-cigarettes.