My friends made me do it: Peer influences and different types of vaping in adolescence.

Vaping is one of the most common forms of substance use among adolescents. Social influences play a key role in the decision to use substances and frequency of use during adolescence, and vaping is no exception. Using a sample of 891 adolescents across two time points (Mage = 15.1 and Mage = 17.2) in this pre-registered study, we explored whether the frequency of vaping nicotine and the frequency of vaping marijuana at age 17 were related to concurrent reports of resistance to peer influence (RPI), perceptions of friends vaping, and perceptions of classmates vaping. Then, we investigated whether resistance to peer influence reported at age 15 was similarly related to age 17 vaping of both substances. Higher RPI at both ages 15 and 17 was associated with a higher probability of abstaining from vaping both substances but was not related to the frequency of vaping among those who vaped. Perceiving that a higher proportion of friends - but not classmates - vaped was associated with a lower probability of abstaining and a greater frequency of vaping among those who vape (for both substances). Higher RPI had an attenuating effect on the relation between perceptions of vaping among peers and an adolescent's own vaping behavior, but that differed by age and peer group (e.g., friends vs. classmates). Overestimation about the prevalence of classmate vaping may have played a role in the findings, but our results suggest that interventions to strengthen peer resistance across adolescence are warranted.

Adolescent E-Cigarette Expectancies: Measure Development and Preliminary Validity of the Electronic Nicotine Vaping Outcomes Measure for Youth.

Background: Electronic nicotine delivery systems ("e-cigarettes") are the nicotine product most commonly used by adolescents. Research, treatment, and policy could benefit from measures of adolescent e-cigarette beliefs about outcomes of use (ie, expectancies). In the current study, we developed and tested an adolescent electronic nicotine vaping expectancy measure. Methods: A focus group with adolescents evaluated potential e-cigarette expectancy items. A panel of national experts assisted in revision of these items. Finally, items were administered to a sample of adolescents 14-17 years old (N = 267, Mean age 15.6, SD = 1.1, 50.9% Female, 50.2% Non-Hispanic White, 22.5% Non-Hispanic Black, 14.2% Hispanic) in a large Southeastern metropolitan area in the United States. Results: Exploratory Factor Analysis revealed a four factor solution: Negative Consequences (Cronbach's α = .92); Positive Reinforcement (α = .83); Negative Affect Reduction (α = .95); and Weight Control (α = .89). Subscales were significantly correlated with vaping susceptibility and lifetime vaping. Subscales successfully differentiated susceptible adolescents from confirmed non-susceptible adolescents, with susceptible adolescents reporting more positive expectancies, eg, Positive Reinforcement, M = 5.0, SD = 2.0 vs M = 3.0, SD = 2.1, P < .001, η2 = 0.19, and less negative expectancies, M = 5.5, SD = 2.3 vs M = 6.5, SD = 2.6, P = .001, η2 = 0.04. Similar results were found comparing adolescents who have never vaped nicotine with those who have vaped nicotine. Hierarchical linear regression demonstrated subscales were significant predictors of lifetime vaping after controlling for demographics, vaping ad exposure, and peer/family vaping. Conclusions: A preliminary version of an adolescent expectancy measure appears reliable and valid based on expert input and pilot testing with adolescents. Promising results were found in the domains of concurrent validity, discriminant validity, and incremental validity. Future research and evaluation efforts will be able to use this tool to further prevention and treatment goals.

An overview of traditional smoking cessation interventions and E-cigarettes.

Many people still struggle with quitting smoking despite available treatment options, making it one of the most significant public health challenges that our society faces. The use of electronic cigarettes (E-cigarettes) has become increasingly popular among people who are seeking to quit smoking. The objective of this review paper is to present a comprehensive analysis of the mechanisms, several types, and impact of E-cigarettes, along with supporting evidence indicating their efficacy in aiding smokers to quit tobacco usage. Additionally, the review discusses recent developments in the treatment of smoking cessation, which include conventional smoking cessation methods. Also, the review discusses the challenges, potential risks, ethical considerations, and controversies surrounding the use of E-cigarettes. The present review presents a comprehensive examination of the existing methods and approaches employed in smoking cessation, including the emerging utilization of E-cigarettes as an effective option in smoking cessation. It explores their efficacy as a valuable instrument in promoting smoking cessation.

Current perspective on e-cigarette use and respiratory outcomes: mechanisms and messaging.

INTRODUCTION: There has been an increasing amount of research on the consequences of e-cigarette use for respiratory outcomes, which is significant for public health and respiratory medicine. We discuss recent findings and lay out implications for prevention and treatment. AREAS COVERED: Based on literature searches using several databases (PubMed, Web of Science, Google Scholar) for keywords, including synonyms, 'e-cigarettes,' with 'pulmonary function,' 'oxidative stress,' and 'inflammation,' we review studies on acute effects of e-cigarette use for measures of pulmonary function and discuss selected laboratory studies on mechanisms of effect, focusing on processes with known relation to respiratory disease; oxidative stress and inflammation. We discuss available studies that have tested the effectiveness of communication strategies for prevention of e-cigarette use oriented to different audiences, including nonsmoking adolescents and adult smokers. EXPERT OPINION: We conclude that the evidence presents a mixed picture. Evidence is found for adverse consequences of e-cigarette use on measures of lung function and two disease-related biological processes, sometimes but not always less than for cigarette smoking. How to best communicate these results to a complex audience of users, from younger susceptible adolescents to long-term adult smokers interested in quitting, is a question of significant interest and empirically validated communication strategies are greatly needed.

Association between the use of electronic cigarettes and myocardial infarction in U.S. adults.

BACKGROUND: Compared with conventional cigarettes, electronic cigarettes are less harmful in some studies. However, recent research may indicate the opposite. This study aimed to determine whether e-cigarette use is related to myocardial health in adults in the U.S. METHODS: This study used data from the 2020 Behavioral Risk Factor Surveillance System (BRFSS), a cross-sectional survey of adult US residents aged 18 years or older. We examined whether e-cigarette use was related to myocardial infarction byapplying a logistic regression model to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The final analytical sample included 198,530 adults in the U.S. Logistic regression indicated that U.S. adults who reported being former and some days of e-cigarette use had 23% and 52% greater odds of ever having an MI, respectively, than did those who reported never using e-cigarettes (OR = 1.23, 95% CI 1.08-1.40, p = 0.001; OR = 1.52, 95% CI 1.10-2.09, p = 0.010). CONCLUSIONS: The results suggest that former and someday users of e-cigarettes probably have increased odds of myocardial infarction in adults in the U.S. Further research is needed, including long-term follow-up studies on e-cigarettes, since it is still unknown whether they should be discouraged.

Aerosolized e-liquid base constituents induce cytotoxicity and genotoxicity in oral keratinocytes.

OBJECTIVE: Electronic cigarette (e-cigarette) use among adults in the United States continues to rise. Particularly concerning is the impact of e-cigarette aerosol inhalation on the oral mucosa. Aerosols are derived from a heated e-liquid base of propylene glycol/glycerin (PG/G) often mixed with nicotine and chemical flavors. Of note, harmful and potentially harmful constituents (HPHCs), including metals and volatile organic compounds, have been detected in e-cigarette aerosols. It remains unknown, however, whether aerosols exclusively derived from e-liquid PG/G are detrimental to oral keratinocytes. The present study analyzed toxicological outcomes in normal oral keratinocytes exposed to model nicotine-free, unflavored PG/G e-liquid aerosols. MATERIALS AND METHODS: Cell viability/cytotoxicity, genotoxicity, and immunoblotting assays were conducted in NOKSI, a gingiva-derived oral keratinocyte cell line, following exposure to model e-liquid aerosols or non-aerosolized controls. The HPHC acrolein, reported to form DNA adducts in the buccal mucosa from e-cigarette users, was also used in similar assays. RESULTS: PG/G e-liquid aerosol extracts significantly enhanced cytotoxic and DNA damaging responses in NOKSI cells when compared to non-aerosolized e-liquid treatment. Acrolein treatment led to similar results. CONCLUSIONS: The aerosolization process of PG/G e-liquid is a critical determinant of marked cytotoxic and genotoxic stimuli in oral keratinocytes.

Direct health implications of e-cigarette use: a systematic scoping review with evidence assessment.

Background: E-cigarettes are often marketed as a less harmful alternative to traditional tobacco cigarettes. Despite their popularity, the evidence regarding their effects on human health remains unclear and is filled with complexities. Objectives: This systematic review aims to elucidate the direct effects of electronic cigarette use on human health, carefully distinguishing between the specific characteristics of the populations studied. Methodology: Adhering to the PRISMA guidelines, we conducted a comprehensive search in PubMed/Medline, Web of Science, Scopus, and Google Scholar databases without date restrictions, including articles in both Spanish and English. This approach enabled the identification and analysis of primary studies to understand the direct effect of electronic cigarettes on human health. Results: A total of 33 studies were included that evaluated cardiovascular, pulmonary, renal, weight and fertility effects. Only five studies analyzed e-cigarettes in healthy populations and seven studies compared healthy individuals against smokers. The effects evaluated on smokers or former tobacco smokers were apparently positive, however, among healthy individuals, increased heart rate, mean arterial pressure, oxidative stress, alteration of respiratory epithelial cells and increased airflow resistance were found. Conclusion: Smokers or former smokers who switch to e-cigarettes may reduce their exposure to carcinogens and lower their risk of developing severe health issues associated with conventional smoking. However, in healthy individuals who have never smoked traditional cigarettes, the use of e-cigarettes introduces several cardiovascular and respiratory adverse effects. These findings suggest that while e-cigarettes can be a strategic harm reduction tool for smokers, they are not a safe option for non-smokers.

The Effect of E-Cigarette Indoor Vaping Restrictions on Infant Mortality.

We estimate the effect of county-level e-cigarette indoor vaping restrictions (IVRs) on infant mortality using United States birth certificates from 2010 to 2015. We estimate difference-in-differences models and find that e-cigarette indoor vaping restrictions increased infant mortality by 0.39 infants per 1,000 live births (12.9%). These effects were disproportionately higher for infants born to younger mothers and in locations with higher baseline levels of prenatal smoking. Infant mortality increased by 34.1% between 100 days to 1 year after IVRs. Infant mortality due to infections and neoplasms were particularly elevated.

E-cigarette use and respiratory illnesses among U.S. adults: An analysis of the population assessment of tobacco and health study.

INTRODUCTION: Electronic cigarettes (e-cigarette) entered the United States marketplace in 2007. Because of the chemical composition of e-cigarette liquid, there are concerns related to its effects on respiratory illnesses. METHODS: Using Wave 4 (2016-2018) of the adult (≥18 years of age) Population Assessment of Tobacco and Health study, logistic regression was used to quantify the association between e-cigarette use and any respiratory illness (asthma, chronic bronchitis, COPD, emphysema, or other lung or respiratory conditions). Age, gender, and the use of other tobacco products were assessed as modifiers of this relationship via interactions on the additive and multiplicative scales. RESULTS: After adjustment, ever e-cigarette use was associated with a 1.32 (95 % confidence intervals [CI]:1.03, 1.69) greater odds of any respiratory illness compared with never e-cigarette users among U.S. adults. When comparing ever and never e-cigarette users, older adults (Odds Ratio [OR] = 1.65, 95 %CI:1.20, 2.26), and ever users of other tobacco products (OR = 1.77, 95 %CI:1.37, 2.29) had greater odds of reporting any respiratory illness than younger adults and those who never used other tobacco products. Among never e-cigarette users, men (OR = 1.51, 95 %CI:1.12, 2.04) were less likely to report any respiratory illness than women. Only the joint effect of age and e-cigarette use on any respiratory illness was statistically significant, suggesting this effect was greater than expected on the additive and multiplicative scales. CONCLUSION: These findings suggest that the relationship between e-cigarette use and any respiratory illness varies with age. Interventions and policies to reduce e-cigarette use should target high-risk groups for any respiratory illness.

The school community's role in addressing vaping: Findings from qualitative research to inform pedagogy, practice and policy.

ISSUE ADDRESSED: E-cigarettes are a significant concern in schools due to their rising use by adolescents. This research aimed to identify current and preferred intervention strategies to respond to vaping in the Western Australian school setting. METHODS: Interviews and focus groups were held with 15 school professionals (leaders, teachers and nurses), parents (n = 12) and students aged 13-17 years (n = 32). Discussions were transcribed verbatim, anonymised and thematically analysed using a deductive approach aligned to the Health Promoting Schools Framework. RESULTS: Participants suggested that limited and varied attention has been directed towards policy in response to vaping in the school setting. Teaching and learning opportunities existed for students, parents and school professionals, albeit somewhat ad hoc in their approach. Additional training would benefit the whole-school community (students, parents and staff) to raise awareness of e-cigarette harms, increase knowledge and build skills in responding to student vaping. CONCLUSIONS: Clearly articulated policies are needed to guide school strategies and actions towards vaping. There needs to be a dedicated, developmentally appropriate, cross-subject vaping curriculum for students that incorporates mental health outcomes and social skills reinforcement; professional development for school staff; awareness of and access to school-based health services for help and information; visual cues to de-normalise vaping and parent and community involvement to support vape-free school environments. SO WHAT?: Comprehensive prevention activities are required to reduce the uptake of vaping among adolescents. Building students', school professionals' and parents' awareness of vaping and strategies to prevent use will contribute to de-normalising and reducing this practice among adolescents.

Depression, anxiety, stress, and current e-cigarette use: Results from the truth longitudinal cohort of youth and young adults (2022-2023).

OBJECTIVE: To examine associations between depression, anxiety, and stress, as measured by the Depression, Anxiety and Stress Scale (DASS-21) scale, with current e-cigarette use. METHODS: Data from the Truth Longitudinal Cohort - a nationally representative sample of youth and young adults - was collected between October 2022 to February 2023. The analytic sample was comprised of participants who provided information on e-cigarette use and the DASS-21 scale (N = 4198). Chi-square statistics were used to determine differences by current e-cigarette use across covariates and DASS-21 items. Logistic regression analyses were applied to the cross-sectional data to determine which scales predicted current e-cigarette use, adjusted for the effects of age, gender identity, race and ethnicity, parental educational attainment, perceived financial situation, and current use of alcohol, marijuana, and other tobacco use. RESULTS: Those who had severe/extremely severe levels of depression, anxiety, and stress had greater odds of current e-cigarette use, relative to those who had normal levels of depression, anxiety, and stress, even after adjusting for covariates. Results also demonstrated associations between age, race/ethnicity, parental education, and current use of alcohol, marijuana, and other tobacco products with current e-cigarette use. LIMITATIONS: Cross-sectional analyses of self-reported data limit the ability to determine directionality of effects between depression, anxiety, stress, and current e-cigarette use. DISCUSSION: More severe levels of depression, anxiety, and stress were associated with a greater likelihood of current e-cigarette use. Future research is needed to evaluate changes in e-cigarette use, in response to depression, anxiety, and stress symptomatology.

Adolescent Perspectives on Their E-Cigarette Initiation Experiences.

PURPOSE: To examine adolescents' perspectives regarding external and internal influences of the e-cigarette initiation process. DESIGN: Semi-structured, in-depth qualitative interviews. SETTING: California, remote videoconference. PARTICIPANTS: Adolescents ages 13-17 who currently or previously used e-cigarettes (n = 47). METHOD: Interviews occurred from May 2020-February 2021. Two researchers coded transcripts based on a codebook developed inductively. Coded excerpts were reviewed to identify encompassing themes related to adolescent e-cigarette initiation. RESULTS: Adolescents were often near e-cigarette use by peers, family members, and others, creating ample opportunities to try e-cigarettes in response to curiosity, peer pressure, and desires to cope with stress or belong to a group. Adverse first experiences were common (eg, throat irritation, nausea), but many adolescents vaped again or continued to use regularly in attempts to cement friendships or alleviate symptoms of stress and anxiety. Specific characteristics of e-cigarette devices, including low-cost, concealability, and variety in designs and flavors facilitated initiation, continued use, and nicotine dependence. CONCLUSIONS: Adolescents progress to e-cigarette use via a multistage process, starting where social expectations and opportunity converge. While individual circumstances vary, many continue to vape as a perceived coping tool for emotional issues, to gain social belonging, or influenced by e-cigarette characteristics that contribute to ongoing use and dependence. Efforts to deter use should address the devices themselves and the social forces driving youth interest in them.

Longitudinal associations of e-cigarette use with cigarette, marijuana, and other drug use initiation among US adolescents and young adults: Findings from the population assessment of tobacco and health study (Waves 1-6).

INTRODUCTION: Research examining prospective links of e-cigarette use with cigarette, marijuana, and other substance use has been limited largely to 1-2-year follow-up periods and focused on younger adolescents. This study examined longitudinal associations of e-cigarette use with cigarette, marijuana, and other substance use initiation among U.S. adolescents and young adults (AYAs) across an eight-year period. METHODS: Adolescent (ages 12-17) and young adult (ages 18-25) data from waves 1-6 of the nationally representative Population Assessment of Tobacco and Health study (2013-2021) were used. Discrete time survival models with time-varying weights were employed to examine the risk of cigarette, marijuana, and other drug use initiation over an eight-year follow-up period among AYAs with no lifetime use of e-cigarettes/other tobacco, lifetime but no past 30-day use of e-cigarettes/other tobacco, past 30-day e-cigarettes only, other tobacco use only, or past 30-day e-cigarette/other tobacco use. We compare our time-varying weighting approach to a traditional time-invariant/complete case weighting approach. RESULTS: Across six follow-up waves, all three past 30-day nicotine/tobacco use groups, including e-cigarettes only, had greater risk for cigarette, marijuana, and other drug use initiation relative to those not using nicotine/tobacco. The three past 30-day nicotine/tobacco use groups did not differ from each other in risk for marijuana use initiation. Associations were smaller in magnitude for young adults compared to adolescents, but significant for both age groups. CONCLUSIONS: Substance use initiation risks persist beyond 1-2 years for U.S. AYAs using e-cigarettes. Prevention strategies to reduce AYA e-cigarette use are needed to reduce cancer-related risk.

Evaluation and comparison of DNA alkylation and oxidative damage in e-cigarette and heated tobacco users.

OBJECTIVES: This study, aimed to determine and compare DNA damage in e-cigarette and HTP (IQOS) users by assessing DNA-adducts, which are biomarkers of various DNA alkylation and oxidation. METHODS: For the evaluation of DNA alkylation, N3-Ethyladenine (N3-EtA) and N3-Methyladenine (N3-MeA) adducts were used. DNA oxidation was assessed using, 8-hydroxy-2'-deoxyguanosine(8-OHdG). The urinary cotinine, N3-MeA, N3-EtA, and 8-OHdG concentrations of the cigarette smokers (n:39), e-cigarette users (n:28), IQOS users (n:20), passive smokers (n:32), and nonsmokers(n:41) who lived Ankara, Turkiye were determined using, liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: In light of the detected 8-OHdG levels, e-cigarette (3.19 ng/g creatinine) and IQOS (4.38 ng/g creatinine) users had higher oxidative DNA damage than healthy nonsmokers (2.51 ng/g creatinine). Alkylated DNA-adducts were identified in the urine of e-cigarette (N3-MeA: 3.92 ng/g creatinine; N3-EtA: 0.23 ng/g creatinine) and IQOS (N3-MeA: 7.54 ng/g creatinine; N3-EtA: 0.29 ng/g creatinine) users. In the generation of N3-MeA adducts, a significant difference was found between IQOS users and e-cigarette users (p < 0.05). Also, DNA alkylation in flavored e-cigarette users (N3-MeA: 4.51 ng/g creatinine; N3-EtA: 0.27 ng/g creatinine) was higher than in non-flavored e-cigarette users (N3-MeA: 2.27 ng/g creatinine; N3-EtA: 0.06 ng/g creatinine). The highest cotinine levels were found in cigarette smokers (16.1316 ng/g creatinine). No significant difference was found when e-cigarette (1163.02 ng/g creatinine) and IQOS smokers were compared (1088.3 ng/g creatinine). CONCLUSION: People who use e-cigarettes and IQOS may be at higher risk of genotoxicity than those who do not use and are not exposed to any tobacco products. Furthermore, the usage of flavoring additives in e-cigarettes contributed to additional genotoxic damage risks.

E-Cigarette Use Behavior and Expectancies Among Sexual Minority and Heterosexual College Student E-Cigarette Users.

Background: College students who identify as a sexual minority (i.e., lesbian, gay, bisexual, or other sexual orientation) are at higher risk for e-cigarette use than their heterosexual or "straight" peers. However, little is known about factors, such as e-cigarette outcome expectancies, that might influence these differences in prevalence rates. Therefore, the current study examined differences between heterosexual and sexual minority college student e-cigarette users in terms of days of past-month e-cigarette use, e-cigarette dependence, and e-cigarette outcome expectancies. A secondary aim of the study was to examine whether outcome expectancies served as an explanatory mechanism in the association between sexual minority status and e-cigarette use frequency and dependence. Methods: Participants were heterosexual (n = 90; Mage = 19.65, SD = 2.70; 76.7% female; 77.8% White) and sexual minority (n = 44; Mage = 20.02, SD = 2.18; 68.2% female; 90.9% White) college student e-cigarette users who completed self-report measures. Results: Students who identified as a sexual minority reported greater e-cigarette dependence, more frequent past 30-day use, and greater negative consequences and positive reinforcement e-cigarette outcome expectancies. Follow-up mediation analyses indicated a significant indirect effect of sexual minority status on both days of past-month e-cigarette use and e-cigarette dependence through expectancies for negative consequences and positive reinforcement. Conclusions: These findings suggest that positive reinforcement and negative consequences outcome expectancies may be contributing to the disparities in e-cigarette use among college students who identify as a sexual minority and could be useful targets for cessation interventions for this population.

Understanding the Cardiovascular Fallout of E-cigarettes: A Comprehensive Review of the Literature.

E-cigarettes (ECs) deliver chemicals, including nicotine. They can cause respiratory distress, addiction, cardiovascular effects, and death. More research is needed, especially regarding their impact on the cardiovascular system (CVS) and during pregnancy. Our article aims to fill this gap by summarizing studies elaborating upon the current impact of ECs and the components thereof on the CVS. Acute respiratory distress outbreaks, nicotine addiction, CVS effects, and deaths have been occasionally reported within this cohort, although these events are not uncommon with neighboring age groups. Randomized control trials implying ECs have some contribution toward quitting smoking have been studied. To regulate EC distribution, the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) have created key checkpoints. Additionally, taxation, pricing, age restriction, and media campaigns could be modulated to significantly reduce illicit sales. Education to the users, distributors, and regulators about this product can also play an aiding role in promoting responsible EC use. Another strategy about licensing could be employed, which could incentivize genuine resellers. The effects on CVS and child-bearing by ECs are grim, which calls for strict regulation, awareness, and avoidance by the teetotaler public. They may help individuals stop smoking but not without harming themselves. Strict regulations are necessary to prevent non-judicious use of these devices.

Vaping habits and respiratory symptoms using a smartphone app platform.

BACKGROUND: Widespread use of e-cigarette (EC) or vaping products causes respiratory disorders including the nationwide outbreak of e-cigarette or vaping product use-associated lung injury (EVALI) in 2019. Chronic adverse health effects are now being reported as well. To address this important public health issue, an innovative approach of epidemic control and epidemiologic study is required. We aimed to assess the association between short-term and long-term use of EC products and respiratory health in adults using smartphone app data. METHODS: A population-based, repeated measures, longitudinal smartphone app study that performed 8-day survey participation over 60 days for each participant from August 2020 to March 2021, including 306 participants aged 21 years and older in the US. The participants were asked to complete the respiratory health questionnaire daily, weekly, and monthly on their smartphone app. We analyzed the association between vaping habits and respiratory health using generalized linear mixed models (GLMMs). RESULTS: EC use in the previous 7 days was associated with frequent cough (OR: 5.15, 95% CI: 2.18, 12.21), chronic cough (OR: 3.92, 95% CI: 1.62, 9.45), frequent phlegm (OR: 3.99, 95% CI: 1.44, 11.10), chronic phlegm (OR: 3.55, 95% CI: 1.41, 8.96), episodes of cough and phlegm (OR: 4.68, 95% CI: 1.94, 11.28), mMRC grade 3-4 dyspnea (OR: 3.32, 95% CI: 1.35 to 8.13), chest cold (OR: 3.07, 95% CI: 1.29, 7.33), eye irritation (OR: 2.94, 95% CI: 1.34, 6.47) and nose irritation (OR : 2.02, 95% CI: 0.95, 4.30). Relatively long-term effects of the past 90 days EC use was associated with an increased risk of wheeze (OR: 3.04, 95% CI: 1.31, 7.03), wheeze attack (OR: 2.78, 95% CI: 1.07, 7.24), mMRC grade 3-4 dyspnea (OR: 2.54, 9% CI: 1.05 to 6.18), eye irritation (OR: 3.16, 95% CI: 1.49, 6.68), and eye irritation during the past month (OR: 3.50, 95% CI: 1.52, 8.04). CONCLUSIONS: In this smartphone app-based repeated measures study, short-term and relatively long-term use of EC increased the risk of respiratory symptoms.

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.