Unique, long-term effects of nicotine on adolescent brain

Saliva and Lung Microbiome Associations with Electronic Cigarette Use and Smoking

The microbiome has increasingly been linked to cancer. Little is known about the lung and oral cavity microbiomes in smokers, and even less for electronic cigarette (EC) users, compared with never-smokers. In a cross-sectional study (n = 28) of smokers, EC users, and never-smokers, bronchoalveolar lavage and saliva samples underwent metatranscriptome profiling to examine associations with lung and oral microbiomes. Pairwise comparisons assessed differentially abundant bacteria species. Total bacterial load was similar between groups, with no differences in bacterial diversity across lung microbiomes. In lungs, 44 bacteria species differed significantly (FDR < 0.1) between smokers/never-smokers, with most decreased in smokers. Twelve species differed between smokers/EC users, all decreased in smokers of which Neisseria sp. KEM232 and Curvibacter sp. AEP1-3 were observed. Among the top five decreased species in both comparisons, Neisseria elongata, Neisseria sicca, and Haemophilus parainfluenzae were observed. In the oral microbiome, 152 species were differentially abundant for smokers/never-smokers, and 17 between smokers/electronic cigarette users, but only 21 species were differentially abundant in both the lung and oral cavity. EC use is not associated with changes in the lung microbiome compared with never-smokers, indicating EC toxicity does not affect microbiota. Statistically different bacteria in smokers compared with EC users and never-smokers were almost all decreased, potentially due to toxic effects of cigarette smoke. The low numbers of overlapping oral and lung microbes suggest that the oral microbiome is not a surrogate for analyzing smoking-related effects in the lung.

PREVENTION RELEVANCE

The microbiome affects cancer and other disease risk. The effects of e-cig usage on the lung microbiome are essentially unknown. Given the importance of lung microbiome dysbiosis populated by oral species which have been observed to drive lung cancer progression, it is important to study effects of e-cig use on microbiome.

"Genetic influences impacting nicotine use and abuse during adolescence: insights from human and rodent studies"

Nicotine use continues to be a major public health concern, with an alarming recent rise in electronic cigarette consumption. Heritability estimates of nicotine use and abuse range from 40-80%, providing strong evidence that genetic factors impact nicotine addiction-relevant phenotypes. Although nicotine use during adolescence is a key factor in the development of addiction, it remains unclear how genetic factors impact adolescent nicotine use and abuse. This review will discuss studies investigating genetic factors impacting nicotine use during adolescence. Evidence from both rodent and human studies will be summarized and integrated when possible. Human adolescent studies have largely included candidate gene studies for genes identified in adult populations, such as genes involved in nicotine metabolism, nicotinic acetylcholine receptor signaling, dopaminergic signaling, and other neurotransmitter signaling systems. Alternatively, rodent studies have largely taken a discovery-based approach identifying strain differences in adolescent nicotine addiction-relevant behaviors. Here, we aim to answer the following three questions by integrating human and rodent findings: 1) Are there genetic variants that uniquely impact nicotine use during adolescence? 2) Are there genetic variants that impact both adolescent and adult nicotine use? and 3) Do genetic factors in adolescence significantly impact long-term consequences of adolescent nicotine use? Determining answers for these three questions will be critical for the development of preventative measures and treatments for adolescent nicotine use and addiction.

Electronic Cigarettes: Are They Smoking Cessation Aids or Health Hazards?

The US Food and Drug Administration (FDA) recently approved the marketing of an electronic cigarette (e-cig) brand called Vuse (RJ Reynolds Vapor Company, US) to help aid in smoking cessation for adult smokers. It was believed that the consumption of traditional cigarettes and their harmful effects would be reduced given the availability of newer e-cigarettes. However, adolescent use of tobacco and nicotine products rather increased with the availability of the same e-cigarettes, and the FDA-approved market boom only worsened this problem. Although the FDA underlines the importance of marketing e-cigarettes as a possible solution for adult traditional smoking, its consequences on adolescents' health raise many concerns, which we narrated in this review article.

Neuroscience Outside the Box: From the Laboratory to Discussing Drug Abuse at Schools

One of the effects of the current COVID-19 pandemic is that low-income countries were pushed further into extreme poverty, exacerbating social inequalities and increasing susceptibility to drug use/abuse in people of all ages. The risks of drug abuse may not be fully understood by all members of society, partly because of the taboo nature of the subject, and partly because of the considerable gap between scientific production/understanding and communication of such knowledge to the public at large. Drug use is a major challenge to social development and a leading cause of school dropout rates worldwide. Some public policies adopted in several countries in recent decades failed to prevent drug use, especially because they focused on imposing combative or coercive measures, investing little or nothing in education and prevention. Here we highlight the role of neuroscience education as a valid approach in drug use education and prevention. We propose building a bridge between schools and scientists by promoting information, student engagement and honest dialogue, and show evidence that public policy regulators should be persuaded to support such science-based education programs in their efforts to effect important positive changes in society.

Use of Tobacco and Nicotine Products among Young People in Denmark-Status in Single and Dual Use

Lots of new tobacco or nicotine products are being launched, e.g., e-cigarettes and smokeless tobacco, which appeal especially to the youngest part of the population. For example, the use of smokeless tobacco among Danish youth rose from approx. 2% in 2010 to 9% in 2020. Hence, there is an urgent need to follow and intervene against youth tobacco or nicotine product use. This study explored the current use of cigarettes, e-cigarettes, heated tobacco, and smokeless tobacco among Danish 15- to 29-year-olds. Further, we examined the concurrent use of two products or more. We used a nationwide survey conducted among 15- to 29-year-olds in February and March 2020. Overall, approx. 35,700 individuals received the questionnaire of which 35.5% responded (n = 13,315). One out of five (20.1%) smoked cigarettes, half of them daily, the other half occasionally. About one in twenty (3.9%) used e-cigarettes (daily or occasionally), and more than one in three (31.6%) had tried e-cigarettes. The use of heated tobacco among Danish youth is still relatively limited (0.3%). In comparison, about 9% used smokeless tobacco (daily or occasionally). Overall, 27.0% stated that they use at least one type of tobacco or nicotine product, while 5.6% used more than one product. Monitoring tobacco-related behavior in youth provides extremely important information for, e.g., policymakers and health professionals.

Sex- and Genotype-Dependent Nicotine-Induced Behaviors in Adolescent Rats with a Human Polymorphism (rs2304297) in the 3'-UTR of the CHRNA6 Gene

In human adolescents, a single nucleotide polymorphism (SNP), rs2304297, in the 3′-UTR of the nicotinic receptor subunit gene, CHRNA6, has been associated with increased smoking. To study the effects of the human CHRNA6 3′-UTR SNP, our lab generated knock-in rodent lines with either C or G SNP alleles. The objective of this study was to determine if the CHRNA6 3′-UTR SNP is functional in the knock-in rat lines. We hypothesized that the human CHRNA6 3′-UTR SNP knock-in does not impact baseline but enhances nicotine-induced behaviors. For baseline behaviors, rats underwent food self-administration at escalating schedules of reinforcement followed by a locomotor assay and a series of anxiety tests (postnatal day (PN) 25-39). In separate cohorts, adolescent rats underwent 1- or 4-day nicotine pretreatment (2×, 30 μg/kg/0.1 mL, i.v.). After the last nicotine injection (PN 31), animals were assessed behaviorally in an open-field chamber, and brain tissue was collected. We show the human CHRNA6 3′-UTR SNP knock-in does not affect food reinforcement, locomotor activity, or anxiety. Further, 4-day, but not 1-day, nicotine exposure enhances locomotion and anxiolytic behavior in a genotype- and sex-specific manner. These findings demonstrate that the human CHRNA6 3′-UTR SNP is functional in our in vivo model.

Associations of adverse childhood experiences with smoking initiation in adolescence and persistence in adulthood, and the role of the childhood environment: Findings from the 1958 British birth cohort

Adverse childhood experiences (ACEs) have been identified as a strong determinant of smoking. We aimed to examine the association between ACEs and early smoking initiation and subsequent persistence and the contribution of five pathways including family factors, parental involvement, material living conditions, social activities and conscientiousness. Data are from 7414 individuals born in 1958 in Great Britain included in the National Child Development Study. ACEs were measured at ages 7, 11, and 16. Smoking initiation was derived from smoking variables from ages 16 to 42 and persistent smoking was derived from smoking variables from ages 23 to 42. We modelled the relationship between ACEs and smoking, and further assessed the contribution of each pathway using multinomial logistic regressions. During childhood, 20.9% of respondents experienced one ACE and 6.4% two or more. Those who experienced ACEs had a higher risk of initiating smoking by age 16 and of persistent smoking (RRR _{initiation by 16y} = 1.89 [1.62; 2.20] for one ACE; RRR _{initiation by 16y} = 2.36 [1.81; 3.08] for two or more ACEs, and RRR _{persistent smoking} = 2.07 [1.73; 2.47] for one ACE, RRR _{persistent smoking} = 2.59 [1.92; 3.49] for two or more ACEs). The factors that contributed most to explaining these associations were parental smoking, sibling order and conscientiousness. ACEs remained associated with persistent smoking after further adjusting for young adulthood variables. Smoking prevention measures may need to be tailored when considering adolescents from communities where ACEs are more prevalent to curtail initiation, intensity and persistence. FUNDING: This work was supported by the Institut National du Cancer & the Institut de recherche en santé publique (grant agreement: No. [2019-204]).

Socioeconomic Differences in Cigarette Smoking and Alternative Tobacco Product Use Among Adolescents in a School-Based Smoking Preventive Intervention: Findings From the Second Year of the X:IT II Study

Background

Health interventions may differently impact adolescents from diverse backgrounds. This study examined whether a smoking preventive intervention was equally effective in preventing cigarette smoking and use of alternative tobacco products (ATPs, i.e., snus, e-cigarettes, and waterpipe) among students from different socioeconomic backgrounds, i.e., occupational social classes (OSC).

Methods

Data was from the school-based intervention X:IT II targeting 13- to 15-year-olds Danes. The intervention focused on three main components: smoke-free school time, smoke-free curriculum, and parental involvement. In total, 46 schools were included at baseline (N = 2,307, response rate = 86.3%). Using a difference-in-differences approach, changes in current smoking and ever use of ATPs were estimated among students in high versus low OSC at second follow-up. Analyses were based on available cases (N = 826) and multiple imputations of missing data at the second follow-up (N = 1,965).

Results

At baseline (age 13), 1.0% of students from high OSC and 4.8% from low OSC currently smoked cigarettes, while this was the case among 24.5 and 25.6%, respectively, at the second follow-up (age 15). Estimates indicated that social inequalities in current smoking diminished over time (p < 0.001). Regarding ATPs, 10.0% of high OSC students and 13.9% of low OSC students had ever used ATPs at baseline, while at second follow-up, 46.8 and 60.8%, respectively, had ever used ATPs. Estimates indicated that social inequalities in ever use of ATPs widened over time (p < 0.001).

Conclusions

The X:IT II intervention seemed to diminish socioeconomic disparities in smoking over the study period. Meanwhile, social inequalities in ever use of ATPs increased. Therefore, besides focusing on narrowing the social disparities in cigarette smoking, future efforts may, to a larger extent, focus on adolescents' use of ATPs.

Unique effects of nicotine across the lifespan

Smoking remains the leading cause of preventable death in the United States. Although combustible cigarettes are largely being replaced by tobacco-free products, nicotine use continues to increase in vulnerable populations, including youth, adolescents, and pregnant women. Nicotine exerts unique effects on specific brain regions during distinct developmental periods due to the dynamic expression of nicotinic acetylcholine receptors (nAChRs) throughout the lifespan. Nicotine exposure is a health concern not only for adults but also has neurotoxic effects on the fetus, newborn, child, and adolescent. In this review, we aim to highlight the dynamic roles of nAChRs throughout gestation, adolescence, and adulthood. We also provide clinical and preclinical evidence of the neurodevelopmental, cognitive, and behavioral consequences of nicotine exposure at different developmental periods. This comprehensive review highlights unique effects of nicotine throughout the lifespan to help elucidate interventions and public health measures to protect sensitive populations from nicotine exposure.

From Tobacco Cigarettes to Electronic Cigarettes: The Two Sides of a Nicotine Coin

Tobacco smoking-related diseases, including cardiovascular disease, pulmonary disease, stroke, and cancer in multiple organ sites, are the leading causes of preventable death, worldwide. Youth electronic cigarette use (vaping) is an evolving public health problem in the United States and around the world. Many of the same toxicants and carcinogens present in tobacco smoke are also found in electronic cigarette vapor, although mostly at substantially lower levels. The reduced concentrations of these chemicals in electronic cigarette vapor may imply lower health risk; however, they cannot equate to no risk. To date, the long-term health consequences of vaping are largely unknown. This “Perspective” provides a concise chronology of events leading up to an unprecedented global challenge, namely the convergence of global tobacco epidemic and youth vaping epidemic. Current state of knowledge, outstanding questions in the field, present challenges, and future directions in research are highlighted. The existing data show a continued and dynamic evolution of the converged epidemics. The goal should be to prevent youth vaping while improving smoking cessation strategies. In smokers who are unable or unwilling to quit smoking, the objective should be to provide “provably” safe or less-harmful alternatives, which should “completely” or “substantially” substitute tobacco cigarettes.

Chronic tobacco smoking, impaired reward-based decision-making, and role of insular cortex: A comparison between early-onset smokers and late-onset smokers

INTRODUCTION

The literature suggests that tobacco smoking may have a neurotoxic effect on the developing adolescent brain. Particularly, it may impair the decision-making process of early-onset smokers (<16 years), by rendering them more prone to impulsive and risky choices toward rewards, and therefore more prone to smoking relapses, in comparison to late-onset smokers (≥16 years). However, no study has ever investigated reward-based decision-making and structural brain differences between early-onset smokers and late-onset smokers.

METHODS

Computerized measures of reward-based decision-making [Cambridge Gambling Task (CGT); 5-trials adjusting delay discounting task (ADT-5)] were administered to 11 early-onset smokers (mean age at regular smoking initiation = 13.2 years), 17 late-onset smokers (mean age at regular smoking initiation = 18.0 years), and 24 non-smoker controls. Voxel-based morphometry (VBM) was utilized to investigate the gray matter (GM) and white matter (WM) volume differences in fronto-cortical and striatal brain regions between early-onset smokers, late-onset smokers, and non-smokers.

RESULTS

Early-onset smokers displayed a riskier decision-making behavior in comparison to non-smokers as assessed by the CGT (p < 0.01, Cohen's f = 0.48). However, no significant differences (p > 0.05) in reward-based decision-making were detected between early-onset smokers and late-onset smokers. VBM results revealed early-onset smokers to present lower GM volume in the bilateral anterior insular cortex (AI) in comparison to late-onset smokers and lower WM volume in the right AI in comparison to late-onset smokers.

CONCLUSION

Impairments in reward-based decision-making may not be affected by tobacco smoking initiation during early adolescence. Instead, lower GM and WM volume in the AI of early-onset smokers may underline a vulnerability to develop compulsive tobacco seeking and smoking behavior during adulthood.

Nicotine Exposure during Adolescence Leads to Changes of Synaptic Plasticity and Intrinsic Excitability of Mice Insular Pyramidal Cells at Later Life

To find satisfactory treatment for nicotine addiction, synaptic and cellular mechanisms should be investigated comprehensively. Synaptic transmission, plasticity and intrinsic excitability in various brain regions are known to be altered by acute nicotine exposure. However, it has not been addressed whether and how nicotine exposure during adolescence alters these synaptic events and intrinsic excitability in the insular cortex in adulthood. To address this question, we performed whole-cell patch-clamp recordings to examine the effects of adolescent nicotine exposure on synaptic transmission, plasticity and intrinsic excitability in layer V pyramidal neurons (PNs) of the mice insular cortex five weeks after the treatment. We found that excitatory synaptic transmission and potentiation were enhanced in these neurons. Following adolescent nicotine exposure, insular layer V PNs displayed enhanced intrinsic excitability, which was reflected in changes in relationship between current strength and spike number, inter-spike interval, spike current threshold and refractory period. In addition, spike-timing precision evaluated by standard deviation of spike timing was decreased following nicotine exposure. Our data indicate that adolescent nicotine exposure enhances synaptic transmission, plasticity and intrinsic excitability in layer V PNs of the mice insular cortex at later life, which might contribute to severe nicotine dependence in adulthood.

Age- and Sex-Dependent Nicotine Pretreatment Effects on the Enhancement of Methamphetamine Self-Administration in Sprague-Dawley Rats

INTRODUCTION

Initiation of tobacco products typically occurs in adolescence. Adolescence is a critical period in development where the maturation of brain neurocircuitry is vulnerable to nicotine. Nicotine-containing products and psychostimulants, such as methamphetamine (METH), are often co-abused. Rodent studies have shown that nicotine exposure in early adolescence increases subsequent drug intake and reward. Given the exponential increase in e-cigarette use among adolescents, there is a pressing need to understand whether adolescent nicotine exposure impacts concurrent increased methamphetamine use. The objective of this study is to evaluate age, sex, and longitudinal effects of nicotine pretreatment on methamphetamine reinforcement.

METHODS

Male and female Sprague-Dawley rats were pretreated with a sub-chronic, low dose nicotine (2x, 30 μg/kg/0.1 mL, intravenous) or saline during early adolescence (postnatal days 28-31) or adulthood (postnatal days 86-89). Following nicotine pretreatment, on postnatal day 32 or postnatal day 90, animals underwent operant intravenous self-administration for methamphetamine (20 μg/kg/inf) over a 2-hour period for five consecutive days.

RESULTS

Early adolescent nicotine exposure enhances intravenous methamphetamine self-administration in male, but not female adolescents. Male adult rats self-administer methamphetamine over the 5-day testing period, independent of nicotine exposure. In contrast, nicotine exposure increases methamphetamine self-administration in female adults during the later sessions of the 5-day testing period.

CONCLUSIONS

Taken together, our data highlight age- and sex-dependent effects of low dose, sub-chronic nicotine pretreatment on subsequent intravenous methamphetamine self-administration.

IMPLICATIONS

A majority of polysubstance users begin smoking before the age of 18. Mounting evidence highlights adolescent susceptibility to nicotine exposure on brain and behavior. With the escalation in nicotine-containing products and stimulant use among adolescents, it is important to identify the consequences from adolescent nicotine use, including polysubstance use. Our study provides evidence that adolescent nicotine exposure enhances subsequent methamphetamine use, with important sex- and age-dependent effects.

New Zealand Youth19 survey: vaping has wider appeal than smoking in secondary school students, and most use nicotine-containing e-cigarettes

OBJECTIVE

To investigate smoking and vaping in secondary school students (aged 13-18 years) in New Zealand (NZ) following the introduction of 'pod' e-cigarettes, which have been associated with the rapid escalation of youth vaping elsewhere.

METHODS

Data on smoking and vaping were collected in 2019 as part of a comprehensive youth health survey (N=7,721).

RESULTS

Vaping was 2-3 times more prevalent than smoking, with 10% of students vaping regularly (monthly or more often), and 6% weekly or more often, compared with 4% and 2%, respectively, for tobacco smoking. Nicotine-containing e-cigarettes were sometimes or always used by 80% of regular and 90% of weekly vapers. Regular and weekly smoking was rare in low deprivation (affluent) areas, whereas regular and weekly vaping prevalence was similar across the socioeconomic spectrum. More than 80% of ever-vapers (N=2732) reported they were non-smokers when they first vaped, and 49% of regular vapers (N=718) had never smoked.

CONCLUSIONS

A significant proportion of New Zealand adolescents, many of whom have never smoked, use nicotine-containing e-cigarettes regularly. Implications for public health: Vaping is less harmful than smoking, but it is not harmless. Public health action is needed to support young non-smokers to remain smokefree and vape-free.

Does nicotine exposure during adolescence modify the course of schizophrenia-like symptoms? Behavioral analysis in a phencyclidine-induced mice model

The first symptoms of schizophrenia (SCHZ) are usually observed during adolescence, a developmental period during which first exposure to psychoactive drugs also occurs. These epidemiological findings point to adolescence as critical for nicotine addiction and SCHZ comorbidity, however it is not clear whether exposure to nicotine during this period has a detrimental impact on the development of SCHZ symptoms since there is a lack of studies that investigate the interactions between these conditions during this period of development. To elucidate the impact of a short course of nicotine exposure across the spectrum of SCHZ-like symptoms, we used a phencyclidine-induced adolescent mice model of SCHZ (2.5mg/Kg, s.c., daily, postnatal day (PN) 38-PN52; 10mg/Kg on PN53), combined with an established model of nicotine minipump infusions (24mg/Kg/day, PN37-44). Behavioral assessment began 4 days after the end of nicotine exposure (PN48) using the following tests: open field to assess the hyperlocomotion phenotype; novel object recognition, a declarative memory task; three-chamber sociability, to verify social interaction and prepulse inhibition, a measure of sensorimotor gating. Phencyclidine exposure evoked deficits in all analyzed behaviors. Nicotine history reduced the magnitude of phencyclidine-evoked hyperlocomotion and impeded the development of locomotor sensitization. It also mitigated the deficient sociability elicited by phencyclidine. In contrast, memory and sensorimotor gating deficits evoked by phencyclidine were neither improved nor worsened by nicotine history. In conclusion, our results show for the first time that nicotine history, restricted to a short period during adolescence, does not worsen SCHZ-like symptoms evoked by a phencyclidine-induced mice model.

Associations of clinical, psychological, and socioeconomic characteristics with nicotine dependence in smokers

Cigarette smoking is a risk factor of mortality and morbidity from various cancerous, respiratory, and myocardial diseases. Nicotine dependence is assessed based on the degree of physical dependence. We aimed to determine the clinical, socioeconomic and psychological factors associated with the smoking status and degree of nicotine dependence of smokers. From April 2009 to September 2010, we retrospectively collected data from 17,577 subjects aged ≥ 18 years who had undergone a general health examination at a health promotion center. The instruments used included the Fagerström Tolerance Questionnaire (FTQ), Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), Stress Response Inventory (SRI), and Alcohol Use Disorder Identification Test (AUDIT). Of the current smokers (N = 3946), 2345 (59%), 1154 (29%), and 447 (12%) had low, moderate, and high nicotine dependence, respectively. In multiple logistic analysis, predictors of high nicotine dependence were male sex (odds ratio [OR] 3.705, 95% confidence interval [CI] 1.997–6.945), older age (≥ 65 years) (OR 1.016, 95% CI 1.004–1.029), higher body mass index (BMI) (OR 1.048, 95% CI 1.018–1.078), diabetes (OR 1.870, 95% CI 1.251–2.794), single marital status (OR 1.575, 95% CI 1.186–2.092), lower education level (OR 1.887, 95% CI 1.463–2.433), and a higher stress level (OR 1.018, 95% CI 1.997–6.945). Thus, clinical, psychological, socioeconomic status including male, older age, higher BMI, diabetes, single marital status, lower education, and higher stress should be taken into consideration by promoting smoking cessation.

Effects of adolescent substance use disorders on central cholinergic function

Adolescence is a transitional period between childhood and adulthood, in which the individual undergoes significant cognitive, behavioral, physical, emotional, and social developmental changes. During this period, adolescents engage in experimentation and risky behaviors such as licit and illicit drug use. Adolescents' high vulnerability to abuse drugs and natural reinforcers leads to greater risk for developing substance use disorders (SUDs) during adulthood. Accumulating evidence indicates that the use and abuse of licit and illicit drugs during adolescence and emerging adulthood can disrupt the cholinergic system and its processes. This review will focus on the effects of peri-adolescent nicotine and/or alcohol use, or exposure, on the cholinergic system during adulthood from preclinical and clinical studies. This review further explores potential cholinergic agents and pharmacological manipulations to counteract peri-adolescent nicotine and/or alcohol abuse.

JUUL and other e-cigarettes: Socio-demographic factors associated with use and susceptibility in California

This study examined which socio-demographic factors are associated with susceptibility (lack of commitment to avoid future use), past-12-month and past-30-day use of JUUL and other e-cigarettes, and reasons for and against using JUUL. An online survey of 3,075 Californians ages 15-29, including 24.3% who identified as LGBTQ, were recruited via social media in January-March 2019. Multi-level weighted logistic regression models suggest that LGBTQ participants were more likely to be susceptible to JUUL [AOR = 2.11 (1.60, 2.79) (parentheses include 95% Confidence Intervals)] and other e-cigarettes [AOR = 2.31 (1.75, 3.05)], and more likely to use JUUL [AOR = 1.27 (1.02, 1.58)] and other e-cigarettes [AOR = 1.66 (1.35, 2.05)] in the past 12 months. Susceptibility to using JUUL was more likely among adolescents (ages 15-17) [AOR = 1.72 (1.30, 2.28)] and young adults (ages 18-20) [AOR = 1.26 (1.00,1.58)] than adults (ages 21-29). At the community level, living in jurisdictions with higher median household income was associated with a higher likelihood of being susceptible to using JUUL and other e-cigarettes. Compared to non-Hispanic Whites, Asian/Pacific Islanders were less likely to use JUUL [AOR = 0.68 (0.54, 0.86)] and other e-cigarettes [AOR = 0.60 (0.48, 0.76)] in the past 12 months. Past-30-day JUUL use was more likely among males than females [AOR = 1.44 (1.11, 1.88)]. Common reasons for using JUUL were: friends' use, flavors, "safer" than cigarettes, no one will notice, and nicotine rush is greater than other devices. Common reasons against using JUUL were: harmful to self/others, contains nicotine and is addictive. E-cigarette prevention and cessation efforts should include tailored messaging for people who identify as LGBTQ and reinforce reasons for not vaping nicotine.

Balancing Consideration of the Risks and Benefits of E-Cigarettes

The topic of e-cigarettes is controversial. Opponents focus on e-cigarettes' risks for young people, while supporters emphasize the potential for e-cigarettes to assist smokers in quitting smoking. Most US health organizations, media coverage, and policymakers have focused primarily on risks to youths. Because of their messaging, much of the public-including most smokers-now consider e-cigarette use as dangerous as or more dangerous than smoking. By contrast, the National Academies of Science, Engineering, and Medicine concluded that e-cigarette use is likely far less hazardous than smoking. Policies intended to reduce adolescent vaping may also reduce adult smokers' use of e-cigarettes in quit attempts. Because evidence indicates that e-cigarette use can increase the odds of quitting smoking, many scientists, including this essay's authors, encourage the health community, media, and policymakers to more carefully weigh vaping's potential to reduce adult smoking-attributable mortality. We review the health risks of e-cigarette use, the likelihood that vaping increases smoking cessation, concerns about youth vaping, and the need to balance valid concerns about risks to youths with the potential benefits of increasing adult smoking cessation.

Who are the young users of tobacco products? Prevalence and characteristics of Danish adolescents who have either smoked cigarettes, used alternative tobacco products, or used both

Aims:

We examined characteristics (smoking in social relations, binge drinking, and well-being measures) of Danish 13-year-olds in relation to their tobacco use patterns. Ever use of cigarettes exclusively, ever use of alternative tobacco products (ATPs; e-cigarettes, snus, or waterpipe) exclusively, and use of both cigarettes and ATPs were studied.

Methods:

We used self-reported data from students at 46 Danish schools in 2017 comprising 2,307 students (response rate = 86%). Multi-level logistic regression analyses were used to examine the associations between student characteristics and the odds for having ever used any tobacco products, smoked cigarettes exclusively, used ATPs exclusively, or used both cigarettes and ATPs compared with never use of any tobacco products. Unadjusted estimates and estimates adjusted for gender were reported.

Results:

A significant minority of youth (13.2%) had used one or more tobacco products. Of these, 2.0% had exclusively smoked cigarettes, 7.2% had exclusively used ATPs, and 4.0% had used both. Findings showed that all included characteristics (families’ and friends’ smoking, binge drinking, and well-being characteristics) were associated with using any tobacco product; however, students with friends who smoked, had been binge drinking, and had low well-being at home had notably higher odds for having both smoked cigarettes and used ATPs compared to the other tobacco use patterns.

Conclusion:

ATPs were popular among Danish adolescents compared with conventional cigarettes. Thus, prevention efforts among adolescents should not merely focus on the health risks of conventional cigarette smoking but also on ATPs. Students with diverse tobacco use patterns were similar on various characteristics. However, findings indicate that adolescents who had used both conventional cigarettes and ATPs constitute a more risk-averse group in special need of prevention efforts. Gender did not markedly influence the results. These findings may help future strategies aiming at the youngest adolescents at risk of using tobacco products.

The effect of electronic cigarettes exposure on learning and memory functions: behavioral and molecular analysis

Objective: Electronic cigarettes (ECIGs) are battery-powered devices that emit vaporized solutions for the user to inhale. ECIGs are marketed as a less harmful alternative to combustible cigarettes. The current study examined the effects of ECIG aerosol exposure on learning and memory, expression of brain derived neurotrophic factor (BDNF), and the activity of antioxidant enzymes in the hippocampus.Methods: Male Wistar rats were exposed to ECIG aerosol, by a whole-body exposure system, 1 h/day for 1 week, 4 weeks, and 12 weeks. Spatial learning and memory were tested using the Radial Arm Water Maze (RAWM). Hippocampal BDNF protein level, and oxidative stress biomarkers (GPx, SOD, GSH, GSSG, GSH/GSSG ratio) were also assessed.Results: ECIG aerosol exposure for 4 and 12 weeks impaired both short- and long- term memory and induced reductions in the hippocampus BDNF, SOD and GPx activities, and GSH/GSSG ratio (p < 0.05). No changes in any examined biomarkers were observed after 1-week exposure to ECIG aerosol (p > 0.05).Conclusions: ECIG aerosol exposure impaired functional memory and elicited changes in brain chemistry that are consistent with reduced function and oxidative stress.

Association of electronic cigarette use with self-reported difficulty concentrating, remembering, or making decisions in US youth

INTRODUCTION

Electronic cigarette use (vaping) has become increasingly popular among youth. The aim of this study is to determine the cross-sectional association of vaping, smoking, and dual use of these tobacco products with self-reported serious difficulty concentrating, remembering, or making decisions (DCRMD), because of a physical, mental, or emotional condition (PMEC) in US youth.

METHODS

The 2018 National Youth Tobacco Survey (NYTS) data with 18535 youth were used for analysis. All included youth who answered whether they have serious DCRMD and stated their vaping and smoking status. Multivariable weighted logistics regression models were used to examine the association of vaping and smoking with the risk of DCRMD in youth, considering a complex sampling design.

RESULTS

Ever dual users (AOR=4.19; 95% CI: 2.97-5.92), exclusive ever cigarette smokers (AOR=1.50; 95% CI: 1.18-1.91) and exclusive ever e-cigarette users (AOR=3.13; 95% CI: 2.25-4.34) had significantly higher odds of self-reported DCRMD than never users in youth. Subgroup analysis on exclusive ever e-cigarette users who started vaping in middle school or earlier had significantly higher odds of self-reported DCRMD compared to those who started vaping in high school (AOR=1.77; 95% CI: 1.27-2.45). Meanwhile, male youth who were exclusive ever e-cigarette users had higher odds of self-reported DCRMD than female youth who were exclusive ever e-cigarette users (AOR=1.67; 95% CI: 1.25-2.22).

CONCLUSIONS

Vaping, smoking and dual use were associated with self-reported serious difficulty concentrating, remembering, or making decisions because of a physical, mental, or emotional condition in youth, which provided initial evidence on the cross-sectional association between vaping and self-reported cognitive problems.