Vaping Transitions and Incident Depressive Symptoms among Young Adults: A Marginal Structural Model Analysis.

The extent to which vaping influences depression is unclear, but could be estimated through application of novel epidemiologic methods. Among a prospective cohort of young adults from California who screened negative for depression, we estimated repeated measures marginal structural models to examine the association of four vaping transitions from time T to T+1 (persistent use, discontinuation, initiation, persistent nonuse) with risk of clinically significant depressive symptoms at T+1, simultaneously across three ~1.5 year time-intervals between 2017-2021. Stabilized inverse probability of treatment and censoring weights adjusted for time-dependent confounders and selection bias. Among n=3,496 observations (1,806 participants, mean pooled baseline age=19.5), 8.1% reported persistent vaping from T to T+1, 6.2% reported discontinuation (i.e., use at T and no use at T+1), 6.5% initiated e-cigarettes (i.e., no use at T and use at T+1), and 79.2% reported persistent nonuse at both time-points. Compared to persistent vaping at two waves, persistent nonuse (RR=0.76, 95%CI:0.62-0.93) and discontinuation (RR=0.71, 95%CI:0.52-0.96) were associated with lower risk of depression. Associations were robust to sensitivity analyses, including restricting to tobacco naïve participants and varying temporal assumptions to reduce potential for reverse causation. Young adults who consistently avoid or discontinue vaping may be protected from depressive symptom occurrence.

Longitudinal Transitions Between Use of Combustible, Noncombustible, and Multiple Cannabis Products From Adolescence to Young Adulthood and Intersections With Nicotine Use.

Understanding transitions across use of different types of cannabis products and multiple cannabis products and how they intersect with nicotine use in young people can inform etiology and prevention. In this study, we examined transitions across use of combustible and noncombustible forms of cannabis and multiple types of cannabis from adolescence to young adulthood and the role of nicotine use in transitions. In a Southern California longitudinal cohort study (n = 3,298; baseline mean age = 16.1 (standard deviation, 0.4) years) with 9 semiannual survey waves (2015-2021), we used Markov multistate transition modeling to estimate short-term (2-wave) and long-term (9-wave) probabilities of transition across 5 cannabis use states: never use of any product, prior use with no past-6-month (P6M) use of any product, and P6M use of exclusively noncombustible products, exclusively combustible products, and multiple (noncombustible + combustible) products. Sizable transition probabilities from prior and exclusive P6M noncombustible or combustible cannabis use to P6M poly-cannabis-product use were observed in short-term (10.7%-38.9%) and long-term (43.4%-43.8%) analyses. P6M nicotine use increased risk of transitioning from never and prior use to exclusive P6M noncombustible and combustible cannabis use. Cannabis use in any form, even temporary use, during midadolescence may often be followed by poly-cannabis-product use. Nicotine use may amplify the probability of future cannabis use onset or recurrence.

Prospective study of e-cigarette use and respiratory symptoms in adolescents and young adults.

RATIONALE: Electronic cigarette (e-cigarette) aerosol contains volatile aldehydes, including flavourings and oxidant metals with known pulmonary toxicity. OBJECTIVES: To evaluate the associations of e-cigarette use with symptoms of wheeze, bronchitic symptoms and shortness of breath (SOB) across 4 years of prospective data. METHODS: Participants completed questionnaires on respiratory symptoms and past 30-day e-cigarette, cigarette and cannabis use in 2014 (wave 1; N=2094; mean age 17.3 years, SD=0.6 years). Follow-up information was collected in 2015 (wave 2; n=1609), 2017 (wave 3; n=1502) and 2018 (wave 4; n=1637) using online surveys. Mixed-effects logistic regression models evaluated associations of e-cigarette use with respiratory symptoms. MEASUREMENTS AND MAIN RESULTS: Participants were mostly Hispanic white (51.8%) and evenly representative by sex (49.6% female; 50.4% male). Compared with never e-cigarette users, past 30-day e-cigarette users reported increased odds of wheeze (OR 1.81; 95% CI 1.28, 2.56), bronchitic symptoms (OR 2.06; 95% CI 1.58, 2.69) and SOB (OR 1.78; 95% CI 1.23, 2.57), adjusting for study wave, age, sex, race, lifetime asthma diagnosis and parental education. Effect estimates were attenuated (wheeze (OR 1.41; 95% CI 0.99, 2.01), bronchitic symptoms (OR 1.55; 95% CI 1.18, 2.05), SOB (OR 1.48; 95% CI 1.01, 2.18)), after adjusting additionally for current cigarette use, cannabis use and secondhand exposure to e-cigarettes/cigarettes/cannabis. CONCLUSIONS: E-cigarette use in young adults was associated with respiratory symptoms, independent of combustible cannabis and cigarette exposures.

Recall of Flavor at First E-cigarette Use and its Association with E-cigarette Progression: The Mediating Effects of First Sensory Experience.

OBJECTIVE: To test whether the association between flavor at first vape and continued use is mediated through subjective experience at first vape. STUDY DESIGN: In a 2020 cross-sectional survey, 955 young adult ever-vapers recalled their first flavor vaped, subjective experiences at first use, current vaping behavior, nicotine dependence, and quit attempts. A latent class model grouped first-use subjective experiences into classes. Two-part negative binomial hurdle models for each vaping behavior evaluated whether the association of first flavor used with vaping outcomes was mediated by positive experience. RESULTS: Four latent classes (positive, positive and negative, negative, and minimal experience) were further reduced to "any positive experience" (only positive, positive and negative) vs "no positive experience" (negative or minimal). Class membership mediated the association of first flavor used (mint/menthol/ice [ie, "cooling"] or sweet vs other) with each vaping outcome. For example, cooling flavor (vs. other) was associated with positive class membership (OR=3.5; 95%CI:1.5,8.1), which was then associated with any past 30-day vaping (OR=3.9; 95%CI:2.7,5.8) and greater number of vaping days among current vapers (RR=1.9; 95%CI:1.3,2.7) in the two-part hurdle model. Similar results were observed for nicotine dependence and quit attempts, and for sweet (vs. other) flavor for any dependence or quit attempts, but not number of dependence symptoms or quit attempts. CONCLUSIONS: Use of a cooling or sweet flavor at first use was associated with having a positive first vaping sensory experience, and then greater likelihood as a young adult of reporting past 30-day vaping, more vaping days, and greater risk for nicotine dependence, suggesting a key mediating role of first use experience.

Distress about social problems and tobacco and cannabis use outcomes among young adults in Los Angeles County.

OBJECTIVE: To examine associations of concern, worry, and stress about discrimination, shootings/violence, and police brutality and exclusive and dual tobacco and cannabis use among young adults. METHODS: A prospective, racially/ethnically diverse cohort of young adults (n = 1960) living in Los Angeles, California completed a baseline survey in 2020 (age range: 19-23) and a follow-up survey in 2021. Exploratory factor analysis (EFA) was employed on nine variables assessing levels of concern, worry, and stress about societal discrimination, societal shootings/violence, and community police brutality at baseline. Past 30-day tobacco and cannabis use at follow-up was categorized as current exclusive tobacco, exclusive cannabis, and dual tobacco and cannabis (vs never/former) use based on eleven use variables. Multinomial logistic regressions estimated adjusted associations between each factor score (translated to standard deviation units) with exclusive and dual tobacco and cannabis use. RESULTS: The EFA produced four factor scores representing concern/worry/stress (i.e., distress) about community police brutality (F1), distress about societal shootings/violence (F2), and distress about societal discrimination (F3), as well as generalized stress about police brutality, shootings/violence, and discrimination (F4). F1, F2, and F3 were associated with subsequent exclusive current cannabis use, with F1 having the strongest association (OR: 1.35, 95% CI: 1.18-1.55), while only F1 (OR: 1.51, 95% CI: 1.27-1.78) was associated with dual tobacco and cannabis use. None of the factors were associated with exclusive tobacco use. CONCLUSIONS: Young adult concern, worry, and/or stress about social problems may increase risk of cannabis use with or without concurrent tobacco use 6-12 months later.

Association of Race-Ethnicity Intersection With Disparities in Cigarette Smoking in U.S. Adults.

INTRODUCTION: Detailed estimates of disparities in cigarette smoking across single- and multi-race groups and their intersections with ethnicity are lacking. This study estimates the prevalence of self-reported current smoking among intersecting adult race-ethnicity groups in the United States. AIMS AND METHODS: The analysis uses 2018-2019 data from the Tobacco Use Supplement-Current Population Supplement (TUS-CPS; n = 137 471). Self-reported Hispanic origin and race were recoded into 19 mutually exclusive race-by-ethnicity intersecting groups. Weighted race-ethnicity group smoking prevalence were compared to the overall population prevalence and one another. RESULTS: Compared to the U.S. population current smoking prevalence (11.4% [95% CI = 11.2% to 11.6%]), smoking was particularly higher in non-Hispanic American Indian/Alaska Native (AI/AN) groups (20.7% [95% CI = 17.8% to 24.0%]) and non-Hispanic multiracial AI/AN/White (24.4% [95% CI = 20.3% to 29.1%]) and AI/AN/Black (22.4% [95% CI = 14.4% to 33.2%]) groups. Non-Hispanic single-race Asian (5.0% [95% CI = 4.4% to 5.6%]) and Hispanic single-race White (7.2% [95% CI = 6.7% to 7.7%]) smoking prevalence undercut the overall U.S. population prevalence. In pairwise comparisons, smoking prevalence was higher in various non-Hispanic single- and multi-race AI/AN groups than non-AI/AN groups and was lower in various Hispanic groups than non-Hispanic groups. CONCLUSIONS: Smoking prevalence disparities are not monolithic across complex diversity of race and ethnicity in the United States. Accurate identification of priority populations in need of targeted tobacco control efforts may benefit by acknowledging multinomial heterogeneity across intersecting racial and ethnic identities. IMPLICATIONS: Understanding racial and ethnic disparities in cigarette smoking can inform national strategies for reducing health inequities. This study examines cigarette smoking disparities among 19 adult intersecting race-ethnicity groups in the United States using the 2018-2019 TUS-CPS data. Results show higher smoking rates in some non-Hispanic American Indian/Alaska Native and Black groups, while lower rates are seen in Asian and Hispanic individuals. These findings emphasize the need for disaggregated data to tackle smoking disparities and guide targeted prevention efforts.

Sexual and Gender Identity Disparities in Nicotine and Tobacco Use Susceptibility and Prevalence: Disaggregating Emerging Identities Among Adolescents From California, USA.

INTRODUCTION: Prior studies report nicotine/tobacco use disparities for sexual and gender minority (SGM) youth but have insufficiently characterized SGM identity diversity. AIMS AND METHODS: Adolescents (mean age = 15.2) from 11 high schools in Southern California completed surveys in Fall 2021. Ever use of combustible (cigarettes, cigars, hookah) and noncombustible (e-cigarettes, e-hookah, heated tobacco, smokeless/snus, oral nicotine) nicotine/tobacco (among overall sample, n = 3795) and susceptibility to future initiation of cigarettes, e-cigarettes, and flavored non-tobacco oral nicotine (among n = 3331 tobacco-naïve youth) were compared across four gender (male/masculine, female/feminine, transgender male/female, non-binary) and seven sexual (heterosexual, bisexual, pansexual, queer, questioning, gay/lesbian, asexual) identities. RESULTS: Non-binary (vs. cisgender male) youth had greater prevalence of ever combustible (prevalence ratio [PR] = 2.86, 95% confidence intervals (CI): 1.76 to 4.66) and non-combustible (PR = 1.94, 95% CI: 1.31 to 2.86) nicotine/tobacco use, and susceptibility to future nicotine/tobacco initiation (PR range = 2.32-2.68). Transgender (vs. cisgender male) youth had greater susceptibility to nicotine/tobacco use (PR range = 1.73-1.95), but not greater tobacco use prevalence. There was greater prevalence of non-combustible nicotine/tobacco use (PR range = 1.78-1.97) and susceptibility to nicotine/tobacco initiation (PR range = 1.36-2.18) for all sexual minority (vs. heterosexual) identities, except for asexual. Bisexual (PR = 2.03, 95% CI: 1.30 to 3.16) and queer (PR = 2.87, 95% CI: 1.31 to 6.27) youth had higher ever combustible tobacco use than heterosexual youth. Questioning (vs. heterosexual) youth were more susceptible to future tobacco initiation (PR range = 1.36-2.05) but did not differ in ever use. CONCLUSIONS: Disparities in nicotine/tobacco use and susceptibility were present with similar effect sizes across most, but not all, SGM identities. Inclusive measurement of SGM identities in research and surveillance may inform more precise tobacco control efforts to reduce disparities. IMPLICATIONS: Among high school students from Southern California with substantial diversity in sexual and gender identities, there was greater prevalence of tobacco use and susceptibility to future tobacco initiation for most, but not all, sexual and gender minority youth, including those with emerging sexual and gender identities such as non-binary, queer and pansexual. Additionally, findings indicate that tobacco control initiatives targeting youth who are questioning their sexual identities may be particularly important for preventing tobacco use initiation. This study reinforces the importance of measuring diversity within the LGBTQ + community for tobacco use research, and highlights how inclusive measurement can inform more precise tobacco control interventions.

Effects of exposure to snus marketing with versus without modified risk tobacco product claims on snus use intention and perceived harm among young adults.

BACKGROUND: We tested whether snus marketing with modified risk tobacco product (MRTP) claims: (a) promotes accurate knowledge about snus's health effects in young adults and (b) encourages use intentions in only those who use combustible tobacco without attracting other young adult populations. METHODS: A randomised between-subjects experiment was embedded in a 2020 web survey of participants from Los Angeles (aged 19-23 years). Participants viewed mass-marketed snus advertising materials with (n=1212) vs without (n=1225) US Food and Drug Administration-authorised MRTP claims. After advertising exposure, snus use intention and perceptions of snus harms relative to cigarettes or e-cigarettes were measured. RESULTS: Advertisements with versus without MRTP claims did not affect snus use intention (18.0% vs 19.4%) but produced a higher prevalence of perceptions that snus was less harmful than cigarettes (12.6% vs 9.1%; p=0.007) and e-cigarettes (8.0% vs 5.8%; p=0.04). MRTP claim exposure effects did not differ by past 30-day e-cigarette or combustible tobacco use. Snus use intentions after marketing exposure, collapsed across MRTP claim conditions, were higher in those who did versus did not report past 30-day use of e-cigarettes (38.4% vs 14.3%; adjusted OR (95% CI) 2.95 (2.28 to 3.81); p<0.001) or combustible tobacco (44.0% vs 16.2%; adjusted OR (95% CI) 2.26 (1.62 to 3.16); p<0.001). CONCLUSION: Although some young adults who vape or smoke may have snus use intentions, snus MRTP claims might not affect young adults' snus use intentions, regardless of whether they vape/smoke. MRTP claims might modestly increase the accuracy of perceived harms of snus relative to cigarettes while also slightly causing unsubstantiated perceptions of lower harm than e-cigarettes.

Association of over the counter "hangover remedy" use with alcohol use problems and consumption patterns among young adults.

This cross-sectional study of young adults examined associations of hangover remedy use with alcohol use problems. Results suggest that ever-use of hangover remedy products was positively associated with alcohol use problem score, drinks per typical drinking day, and alcohol use disorder symptom count. Use of hangover remedies among young adults merits further scientific and regulatory attention.

Indirect Effects of Body Mass Index and Sweet Taste Responsiveness on E-Cigarette Dependence: The Role of E-Cigarette Motives.

Background: Recent research has shown obesity to be associated with e-cigarette use and appeal, but models have yet to examine how weight status may be related to e-cigarette dependence among e-cigarette users. Objectives: To increase our understanding of pathways from body mass index (BMI) to e-cigarette dependence, the present cross-sectional observational study investigated a model in which BMI, sweet taste responsiveness, and the interaction of BMI and sweet taste responsiveness are associated with e-cigarette dependence indirectly via seven conceptually-distinct motives for e-cigarette use. Data from several e-cigarette clinical laboratory research studies were pooled and analyzed; only current e-cigarette users were included in the analyses (N=330). Structural equation modeling was used to analyze the hypothesized model. Results: BMI was positively associated with lower social/environmental goad motives and higher weight control motives, and BMI x sweet taste interaction terms found that sweet taste responsiveness strengthened the association of BMI and weight control motives. BMI was not directly or indirectly associated with e-cigarette dependence nor was there a bivariate association between BMI and e-cigarette dependence. Sweet taste responsiveness was positively associated with greater affiliative attachment motives, cognitive enhancement motives, cue exposure-associative process motives, weight control motives, and affect enhancement motives. Sweet taste responsiveness was bivariately associated with e-cigarette dependence and mediation paths show indirect relations to e-cigarette dependence via three of the seven motives. Conclusions: The findings suggest that sweet taste responsiveness, opposed to BMI, is associated with a wider range of e-cigarette use motives and indirectly relates to e-cigarette dependence via several e-cigarette use motives.

Adolescent Δ8-THC and Marijuana Use in the US.

Importance: Gummies, flavored vaping devices, and other cannabis products containing psychoactive hemp-derived Δ8-tetrahydrocannabinol (THC) are increasingly marketed in the US with claims of being federally legal and comparable to marijuana. National data on prevalence and correlates of Δ8-THC use and comparisons to marijuana use among adolescents in the US are lacking. Objective: To estimate the self-reported prevalence of and sociodemographic and policy factors associated with Δ8-THC and marijuana use among US adolescents in the past 12 months. Design, Setting, and Participants: This nationally representative cross-sectional analysis included a randomly selected subset of 12th-grade students in 27 US states who participated in the Monitoring the Future Study in-school survey during February to June 2023. Exposures: Self-reported sex, race, ethnicity, and parental education; census region; state-level adult-use (ie, recreational) marijuana legalization (yes vs no); and state-level Δ8-THC policies (regulated vs not regulated). Main Outcomes and Measures: The primary outcome was self-reported Δ8-THC and marijuana use in the past 12 months (any vs no use and number of occasions used). Results: In the sample of 2186 12th-grade students (mean age, 17.7 years; 1054 [48.9% weighted] were female; 232 [11.1%] were Black, 411 [23.5%] were Hispanic, 1113 [46.1%] were White, and 328 [14.2%] were multiracial), prevalence of self-reported use in the past 12 months was 11.4% (95% CI, 8.6%-14.2%) for Δ8-THC and 30.4% (95% CI, 26.5%-34.4%) for marijuana. Of those 295 participants reporting Δ8-THC use, 35.4% used it at least 10 times in the past 12 months. Prevalence of Δ8-THC use was lower in Western vs Southern census regions (5.0% vs 14.3%; risk difference [RD], -9.4% [95% CI, -15.2% to -3.5%]; adjusted risk ratio [aRR], 0.35 [95% CI, 0.16-0.77]), states in which Δ8-THC was regulated vs not regulated (5.7% vs 14.4%; RD, -8.6% [95% CI, -12.9% to -4.4%]; aRR, 0.42 [95% CI, 0.23-0.74]), and states with vs without legal adult-use marijuana (8.0% vs 14.0%; RD, -6.0% [95% CI, -10.8% to -1.2%]; aRR, 0.56 [95% CI, 0.35-0.91]). Use in the past 12 months was lower among Hispanic than White participants for Δ8-THC (7.3% vs 14.4%; RD, -7.2% [95% CI, -12.2% to -2.1%]; aRR, 0.54 [95% CI, 0.34-0.87]) and marijuana (24.5% vs 33.0%; RD, -8.5% [95% CI, -14.9% to -2.1%]; aRR, 0.74 [95% CI, 0.59-0.94]). Δ8-THC and marijuana use prevalence did not differ by sex or parental education. Conclusions and Relevance: Δ8-THC use prevalence is appreciable among US adolescents and is higher in states without marijuana legalization or existing Δ8-THC regulations. Prioritizing surveillance, policy, and public health efforts addressing adolescent Δ8-THC use may be warranted.

Alcohol Use and Life Stressors During the COVID-19 Pandemic: A Longitudinal Study of Young Adults.

Objective: To estimate the extent to which drinking to cope with the COVID-19 pandemic and experiencing pandemic-related life stressors are associated with alcohol use escalation among young adults. Methods: Respondents in Los Angeles, CA, USA (N=2,130) completed prospective cohort study surveys before (baseline; October 2018-November 2019; mean age: 19.7[SD=0.4) and during (follow-up; May-August 2020) the COVID-19 outbreak. Past 30-day drinking days and number of drinks per drinking day were assessed from baseline to follow-up. At follow-up, participants reported drinking to cope with social isolation and pandemic-related stressors. Results: Pandemic-related stressor prevalence ranged from 5.5% (evicted/lost home) to 72.6% (worried about education) and 27.1% drank to cope with social isolation during the pandemic. Respondents who did (vs. did not) report pandemic-related coping drinking were more likely to increase past 30-day drinking days and drinks per drinking day from baseline to follow-up after adjustment for possible confounders. Employment loss/reduction, financial problems, and perceived likelihood of contracting COVID-19 or handling the pandemic poorly were each associated with increases in drinking days or drinks per drinking day. Conclusions: Experiencing certain life stressors and drinking to cope with social isolation may be associated with drinking escalation among young adults during the COVID-19 pandemic.

Modeling cigarette smoking disparities between people with and without serious psychological distress in the US, 1997-2100.

Cigarette smoking rates are significantly higher among people with serious psychological distress (SPD) compared to the general population. US simulation models that project future smoking disparities by SPD status could inform policy interventions, but have not been developed. We calibrated two compartmental models to the National Health Interview Survey 1997-2018 for populations with and without SPD, calculating smoking prevalence, mortality, and life-years lost by SPD status under different scenarios from 2023 to 2100. Under the Status Quo, smoking prevalence among women with SPD falls from 27.0% in 2023 to 10.7% in 2100 (men: 30.1% to 12.2%). For women without SPD, it declines from 9.4% to 3.1% (men: 11.5% to 4.0%). The absolute difference in smoking prevalence between those with and without SPD decreases over time, whereas the relative smoking prevalence ratio increases. From 2023 to 2100, 609,000 premature smoking-attributable deaths would occur in the SPD population, with 8 million life-years lost. Under an ideal tobacco control scenario for people with SPD, in which all smokers quit in 2023 and no new smoking initiation occurs thereafter, up to 386,000 of these premature deaths could be averted with 4.9 million life-years gained. Preventing smoking initiation could avert up to 18% of these deaths, while improving smoking cessation could avert up to 82%. Smoking-related disparities for people with SPD will persist unless a shift in tobacco control substantially improves cessation and prevents initiation in this subpopulation. Smoking disparities by SPD may widen in relative but narrow in absolute terms, so both perspectives should be evaluated.

Prevalence of and disparities in adolescents' susceptibility to novel oral nicotine products marketed as "tobacco-free".

Non-therapeutic, novel oral nicotine products are convenient, discreet to use, and flavored, with increasing sales in the United States. It is unclear whether these products appeal predominantly to adolescents already susceptible to inhalable nicotine products, or whether they attract adolescents who would not otherwise use nicotine. This study examined prevalence and correlates of susceptibility to inhalable and oral nicotine product use among adolescents. Ninth- and tenth-grade students from Southern California who had never used any nicotine product (N = 3129) completed an online survey in Fall 2021 assessing susceptibility to inhalable (i.e., cigarettes, e-cigarettes) and oral (e.g., pouches, gum, gummies) nicotine products. Multinomial logistic regression analyses estimated associations of demographic characteristics with odds of susceptibility to oral, inhalable, or both products. Susceptibility was highest for e-cigarettes (19.7%), followed by cigarettes (15.0%) and nicotine gum, lozenges, tablets and/or gummies (15.0%), and nicotine pouches (8.7%). Dual susceptibility to oral and inhalable products (vs. neither product type) was higher in cisgender female and non-cisgender (vs. cisgender male) adolescents (odds ratios [ORs] = 1.36-2.02; ps < 0.05). Hispanic adolescents (vs. Asian) were more susceptible to both products (OR = 1.47; p < .05). Lower-socioeconomic status (SES) and sexual minority adolescents were more susceptible to oral (ORs = 1.76-1.87; ps < 0.05) and both products (ORs = 1.32-1.88; ps < 0.05), compared to higher-SES and heterosexual adolescents. Adolescents in Southern California may be more susceptible to e-cigarettes than other nicotine/tobacco products. However, appreciable numbers may be susceptible to oral nicotine products, including some youth who might not otherwise use nicotine and youth from populations historically impacted by tobacco-related health disparities.

Sex Differences in the Association of E-cigarette and Cigarette Use and Dual Use With Self-Reported Hypertension Incidence in US Adults.

BACKGROUND: While there is some evidence and conceptual plausibility that tobacco product use is associated with hypertension incidence and that this association varies by sex, extant longitudinal research had been conducted prior to the emergence of e-cigarette and dual e-cigarette and cigarette use. AIMS AND METHODS: Data were analyzed from the US Population Assessment of Tobacco and Health study for adults with no lifetime history of hypertension at wave 1 (2013-2014) who completed waves 2-4 follow-up surveys (2014-2018; n = 16 434). Sex-stratified weighted covariate-adjusted multivariable Cox regression models were used to examine the association between established current e-cigarette or cigarette exclusive or dual-use (as a time-varying and time-lagged regressor) and subsequent self-reported hypertension onset. RESULTS: Weighted cumulative hypertension incidence by wave 4 varied by waves 1-3 e-cigarette, cigarette, and dual use status in females (nonuse [incidence: 9.9%], exclusive e-cigarette use [11.8%], exclusive cigarette use [14.8%], dual-use [12.4%]; p = .003 for omnibus differences among all groups) but not males (nonuse [12.6%], exclusive e-cigarette use [9.7%], exclusive cigarette use [13.7%], dual-use [9.3%]; p = .231). Among females, exclusive cigarette (vs. no) use (hazard ratio: 1.69, 95%CI 1.21 to 2.34; p = .002), but not exclusive e-cigarette or dual-use, was significantly associated with subsequent hypertension. Dose-response models were suggestive that consistent exclusive e-cigarette or dual-use versus nonuse across multiple may be associated with hypertension among females, but results were nonsignificant. CONCLUSIONS: The association of e-cigarette, cigarette, and dual use with hypertension may differ by sex, whereby exclusive cigarette use could be a prospective risk factor for subsequent self-reported hypertension in US adult females. IMPLICATIONS: This nationally representative cohort study provides the very first evidence of whether there are prospective associations of established e-cigarette and cigarette use and dual use with future hypertension onset among US adult females and males. We found that exclusive cigarette smoking was associated with an increased risk of incident hypertension among females, but not males. We observed a trend of a dose-response relationship between e-cigarette use and risk of incident hypertension among female exclusive e-cigarette users or dual e-cigarette and cigarette users. Our study will contribute to understanding the chronic health risks of vaping to prevent the potential long-term e-cigarette use-related health burden.

Recent, national trends in US adolescent use of menthol and non-menthol cigarettes.

OBJECTIVE: In light of the current U.S. Food and Drug Administration (FDA) proposal to ban menthol cigarettes, this study updates trends in menthol cigarette use among adolescents age 13-18 years up to the year 2020. The study considers a potential role for the ban to reduce black/non-black disparities in menthol cigarette use, as well as a counterargument that a ban is not necessary because menthol use is already diminishing. METHODS: Data are from annual, cross-sectional, nationally representative Monitoring the Future (MTF) surveys of 85 547 8th, 10th and 12th grade students surveyed between 2012 and 2020. Analyses include trends in past 30-day menthol and non-menthol cigarette smoking among the total adolescent population, as well as stratified by race/ethnicity. RESULTS: Declines in adolescent menthol and non-menthol cigarette smoking continued through 2020 so that in 2018-2020 past 30-day prevalence for each was less than 1% for non-Hispanic black adolescents and less than 2.2% for non-black adolescents. For non-Hispanic black adolescents no smoking declines in mentholated or non-mentholated cigarette use from 2015-2017 to 2018-2020 were statistically significant, in part because prevalence levels approached a floor effect and had little room to fall further. Menthol levels were lower for non-Hispanic black versus all other adolescents in all study years. CONCLUSIONS: Continuing declines in adolescent menthol prevalence indicate that both menthol prevalence and also black/non-black disparities in its use are steadily decreasing. However, these decreases in adolescence will take decades to reach later ages through generational replacement. Efforts to accelerate menthol decreases will require new initiatives to increase cessation among adult menthol users.

'Ice' flavoured e-cigarette use among young adults.

BACKGROUND: 'Ice' e-cigarette flavours-marketed as a combination of fruity/sweet and cooling flavours (eg, 'blueberry ice' or 'melon ice')-recently entered the US market. The prevalence and correlates of ice flavoured e-cigarette use in young adults are unknown. METHODS: This cross-sectional study of a Los Angeles, California, USA, cohort analysed data from the past 30-day e-cigarette (current) users (n=344; M (SD)=21.2 (0.4) years old) who completed web-based surveys from May-August 2020. The exposure variable was self-reported e-cigarette flavour used most often in the past month (menthol/mint, fruit/sweet or ice). Outcomes included self-reported combustible tobacco use, vaping dependence symptoms, frequency of use and device type used. RESULTS: Among current e-cigarette users, 48.8% reported using ice flavours most often, 33.7% predominately used fruit/sweet and 17.4% used menthol/mint. Using primarily ice-flavour was associated with reporting more past-30-day vaping days (vs menthol/mint: b=4.4, 95% CI (1 to 7.7); vs fruit/sweet: b=3.6, 95% CI (0.8 to 6.4)) and more episodes per vaping day versus fruit/sweet users (b=2.4, 95% CI (0.5 to 4.3)). Ice-flavour users were less likely than menthol/mint users to use JUUL/cartridge-based rechargeable (OR=0.1, 95% CI (0.03 to 0.45)) and more likely than sweet/fruit users to use disposable non-cartridge (OR=3.9, 95% CI (2.1 to 7.4)) devices than refillable/rechargeable tank/pen or other devices. Ice users had greater odds of past 30-day combustible tobacco use versus menthol/mint users (OR=2.7, 95% CI (1.3 to 5.7)) and vaping dependence symptoms than versus sweet/fruit users (OR=2.6, 95% CI (1.5 to 4.4)). CONCLUSION: Young adult use of ice flavoured e-cigarettes may be common and positively associated with combustible tobacco use, nicotine vaping frequency and dependence and use of disposable e-cigarette devices. Further study of the prevalence, determinants and health effects of ice flavoured e-cigarette use is warranted.

Ice flavours and non-menthol synthetic cooling agents in e-cigarette products: a review.

E-cigarettes with cooling flavours have diversified in ways that complicate tobacco control with the emergence of: (1) Ice-hybrid flavours (eg, 'Raspberry Ice') that combine cooling and fruity/sweet properties; and (2) Products containing non-menthol synthetic cooling agents (eg, Wilkinson Sword (WS), WS-3, WS-23 (termed 'koolada')). This paper reviews the background, chemistry, toxicology, marketing, user perceptions, use prevalence and policy implications of e-cigarette products with ice-hybrid flavours or non-menthol coolants. Scientific literature search supplemented with industry-generated and user-generated information found: (a) The tobacco industry has developed products containing synthetic coolants since 1974, (b) WS-3 and WS-23 are detected in mass-manufactured e-cigarettes (eg, PuffBar); (c) While safe for limited oral ingestion, inhalational toxicology and health effects from daily synthetic coolant exposure are unknown and merit scientific inquiry and attention from regulatory agencies; (d) Ice-hybrid flavours are marketed with themes incorporating fruitiness and/or coolness (eg, snow-covered raspberries); (e) WS-23/WS-3 concentrates also are sold as do-it-yourself additives, (f) Pharmacology research and user-generated and industry-generated information provide a premise to hypothesise that e-cigarette products with ice flavours or non-menthol cooling agents generate pleasant cooling sensations that mask nicotine's harshness while lacking certain aversive features of menthol-only products, (g) Adolescent and young adult use of e-cigarettes with ice-hybrid or other cooling flavours may be common and cross-sectionally associated with more frequent vaping and nicotine dependence in convenience samples. Evidence gaps in the epidemiology, toxicology, health effects and smoking cessation-promoting potential of using these products exist. E-cigarettes with ice flavours or synthetic coolants merit scientific and regulatory attention.

Dose-response effects of two nicotine salt formulations on electronic cigarette appeal and sensory attributes.

OBJECTIVES: Various organic acids are used to create nicotine salt formulations, which may improve the appeal and sensory experience of vaping electronic cigarettes (e-cigarettes). This clinical experiment examined the effects of partially and highly protonated forms of two nicotine salt formulations (nicotine lactate and benzoate) versus free-base (no acid additive) on the appeal and sensory attributes of e-cigarettes. METHODS: Current adult tobacco product users (n=116) participated in an online remote double-blind within-subject randomised experiment involving standardised self-administration of e-cigarette solutions varying in nicotine formulation (free-base, 50% nicotine lactate -1:2 lactic acid to nicotine molar ratio, 100% nicotine lactate - 1:1 ratio, 50% nicotine benzoate and 100% nicotine benzoate). Each formulation had equivalent nicotine concentrations (27.0-33.0 mg/mL) and was administered in four flavours in a pod-style device. After each administration, participants rated appeal (liking, disliking and willingness to use again) and sensory attributes (0-100 scale). RESULTS: Compared with free-base nicotine, 50% and 100% nicotine lactate and benzoate yielded higher appeal, smoothness and sweetness and lower harshness and bitterness. Dose-response analyses found 100% vs 50% nicotine salt improved appeal, smoothness, bitterness and harshness for nicotine lactate and sweetness, smoothness and harshness for nicotine benzoate. Solutions with higher pH were associated with worse appeal and sensory attributes across nicotine formulations. Nicotine formulation effects did not differ by tobacco use status and flavours. CONCLUSION: Restricting benzoic acid or lactic acid additives or setting minimal pHs in e-cigarettes merits consideration in regulations designed to reduce vaping among populations deterred from using e-cigarettes with aversive sensory properties. TRIAL REGISTRATION NUMBER: This study was registered under ClinicalTrials.gov Identifier: NCT03742817 under the title 'Effects of e-Cigarettes on Perceptions and Behavior'.

Effects of dual use of e-cigarette and cannabis during adolescence on cigarette use in young adulthood.

INTRODUCTION: E-cigarette and cannabis use by adolescents are risk factors for smoking initiation. We hypothesised that increasingly common dual use of e-cigarette and cannabis in adolescence leads to more frequent cigarette smoking in young adulthood. METHODS: Data are from a prospective cohort study in Southern California, where 1164 participants who ever used nicotine products in their lifetime completed surveys in 12th grade (T1:2016), and at 24-month (T2) and 42-month (T3) follow-ups. Past 30-day use (number of days: range=0-30) of cigarettes, e-cigarettes and cannabis, and nicotine dependence, were assessed in each survey. Nicotine dependence for cigarettes and e-cigarettes was assessed using original and modified (for e-cigarette) Hooked on Nicotine Checklists (number of dependent products: range=0-2). Path analysis examined the mediation process via nicotine dependence linking baseline e-cigarette and cannabis use to subsequent increased cigarette use. RESULTS: Baseline exclusive use of e-cigarettes (baseline prevalence, 2.5%) was associated with 2.61-fold increase in frequency of smoking days at T3 (95% CI 1.04 to 13.1), exclusive cannabis use (26.0%) with 2.58-fold increase (95% CI 1.43 to 4.98), and dual use (7.4%) with 5.84-fold increase (95% CI 3.16 to 12.81), compared with baseline non-users. Nicotine dependence at T2 mediated 10.5% (95% CI 6.3 to 14.7) and 23.2% (95% CI 9.6 to 36.3) of the association of cannabis and dual use, respectively, with increased smoking at T3. DISCUSSION: Adolescent e-cigarette and cannabis use was associated with more frequent smoking during young adulthood, with larger effects of dual use. Associations were partially mediated through nicotine dependence. Dual use of cannabis and e-cigarettes may contribute to the development of nicotine dependence and increased use of combustible cigarettes.