E-Cigarette Use Associated With Asthma Independent of Cigarette Smoking and Marijuana in a 2017 National Sample of Adolescents

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.

Use of Electronic Nicotine Delivery Systems and Age of Asthma Onset Among US Adults and Youths

Importance

The association of use of electronic nicotine delivery systems (ENDS) with the age of asthma onset is unknown.

Objective

To explore the association of past 30-day ENDS use with the age of asthma onset in adults and youths who did not have asthma or chronic obstructive pulmonary disease and never used cigarettes.

Design, Setting, and Participants

This cohort study was a secondary analysis of waves 1 to 6 of the US nationally representative Population of Tobacco and Health Study (2013-2021). Eligible participants included adults (≥18 years) and youths (12-17 years) who did not have asthma or chronic obstructive pulmonary disease at the first wave of participation. Data analysis was conducted from September 2022 to April 2024.

Exposure

Past 30-day ENDS use at the first wave of participation in the study preceding the onset of asthma.

Main outcome and measures

Lower and upper age limits were estimated using the age reported at the first wave of participation and the number of weeks between follow-up waves until asthma was first reported or censored. The association of past 30-day ENDS use with the age of asthma onset was estimated using weighted interval-censoring Cox regression. The cumulative hazard function for the age of asthma onset was estimated using interval-censoring survival analysis.

Results

A total of 24 789 participants were included, with 7766 adults (4461 female [weighted percentage, 59.11%] and 3305 male [weighted percentage, 40.89%]), representing 80.0 million adults, and 17 023 youths (8514 female [weighted percentage, 50.60%] and 8496 male [weighted percentage 49.32%]), representing 33.9 million youths. By age 27 years, 6.2 per 1000 adults reported asthma incidence (hazard ratio [HR], 0.62%; 95% CI, 0.46%-0.75%). While controlling for covariates, there was a 252% increased risk of the onset of asthma at earlier ages for adults who used ENDS in the past 30 days vs adults who did not (adjusted HR, 3.52; 95% CI, 1.24-10.02). For youths, there was no association of ENDS use in the past 30 days with age of asthma onset (adjusted HR, 1.79; 95% CI, 0.67-4.77), which could be due to a lack of statistical power.

Conclusion and relevance

In this cohort study, past 30-day ENDS use among adults was associated with earlier ages of asthma onset. These findings suggest that prevention and cessation programs directed to adults who use ENDS are needed to educate the public, protect public health, prevent adverse health outcomes, and motivate users to stop. Furthermore, modifying symptom-screening asthma guidelines, resulting in earlier asthma detection and treatment, may reduce morbidity and mortality due to asthma.

The potential health effects associated with electronic-cigarette

A good old gateway theory that electronic-cigarettes (e-cigarettes) are widely recognized as safer tobacco substitutes. In actuality, demographics also show that vaping cannibalizes smoking, the best explanation of the data is the "common liability". However, the utilization of e-cigarette products remains a controversial topic at present. Currently, there has been a widespread and substantial growth in e-cigarette use worldwide owing to their endless new flavors and customizable characteristics. Furthermore, e-cigarette has grown widespread among smokers as well as non-smokers, including adolescents and young adults. And some studies have shown that e-cigarette users are at greater risk to start using combustible cigarettes while e-cigarettes use was also observed the potential benefits to people who want to quit smoking or not. Although it is true that e-cigarettes generally contain fewer toxic substances than combustible cigarettes, this does not mean that the chemical composition in e-cigarettes aerosols poses absolutely no risks. While concerns about toxic substances in e-cigarettes and their widespread use in the population are reasonable, it is also crucial to consider that e-cigarettes have been associated with the potential for promoting smoking cessation and the clinically relevant improvements in users with smoking-related pathologies. Meanwhile, there is still short of understanding of the health impacts associated with e-cigarette use. Therefore, in this review, we discussed the health impacts of e-cigarette exposure on oral, nasal, pulmonary, cardiovascular systems and brain. We aspire for this review to change people's previous perceptions of e-cigarettes and provide them with a more balanced perspective. Additionally, we suggest appropriate adjustments on regulation and policy for e-cigarette to gain greater public health benefits.

Population-Based Disease Odds for E-Cigarettes and Dual Use versus Cigarettes

BACKGROUND: E-cigarettes are promoted as less harmful than cigarettes. There has not been a direct comparison of health effects of e-cigarettes or dual use (concurrently using e-cigarettes and cigarettes) with those of cigarettes in the general population. METHODS: Studies in PubMed, EMBASE, Web of Science, and PsychINFO published through October 1, 2023, were pooled in a random-effects meta-analysis if five or more studies were identified with a disease outcome. We assessed risk of bias with Risk Of Bias In Non-randomized Studies of Exposure and certainty with Grading of Recommendations, Assessment, Development, and Evaluations. Outcomes with fewer studies were summarized but not pooled. RESULTS: We identified 124 odds ratios (94 cross-sectional and 30 longitudinal) from 107 studies. Pooled odds ratios for current e-cigarette versus cigarette use were not different for cardiovascular disease (odds ratio, 0.81; 95% confidence interval, 0.58 to 1.14), stroke (0.73; 0.47 to 1.13), or metabolic dysfunction (0.99; 0.91 to 1.09) but were lower for asthma (0.84; 0.74 to 0.95), chronic obstructive pulmonary disease (0.53; 0.38 to 0.74), and oral disease (0.87; 0.76 to 1.00). Pooled odds ratios for dual use versus cigarettes were increased for all outcomes (range, 1.20 to 1.41). Pooled odds ratios for e-cigarettes and dual use compared with nonuse of either product were increased (e-cigarette range, 1.24 to 1.47; dual use, 1.49 to 3.29). All included studies were assessed as having a low risk of bias. Results were generally not sensitive to study characteristics. Limited studies of other outcomes suggest that e-cigarette use is associated with additional diseases. CONCLUSIONS: There is a need to reassess the assumption that e-cigarette use provides substantial harm reduction across all cigarette-caused diseases, particularly accounting for dual use.

Co-Use of Tobacco Products and Cannabis Is Associated with Absenteeism and Lower Grades in California High School Students

OBJECTIVE

To examine the association between co-use of commercial tobacco product (hereafter referred to as tobacco) and cannabis with educational outcomes among high school students.

STUDY DESIGN

We analyzed high school student data from the 2021-2022 California Healthy Kids Survey (n = 287 653). Current (past-month) or ever tobacco and cannabis use was categorized as co-use, only tobacco or cannabis, or neither. Two self-reported educational outcomes were examined: absenteeism and grades. Adjusted logistic and linear regression models were used to examine the association between tobacco/cannabis use and absenteeism or grades, respectively. Estimates were adjusted for individual, peer, and school covariates, and clustering within schools.

RESULTS

Current co-use of tobacco and cannabis was more than double the use of only tobacco (3.7% vs 1.7%) and similar to only cannabis (3.7%). Almost 18% of students reported absenteeism. Compared with students who used neither substance, students with current co-use had greater odds of absenteeism (aOR 1.41, 95% CI 1.33-1.49) and lower grades (β = -0.87, 95% CI -0.92 to -0.82). Compared with students using tobacco alone, students with co-use also had a significant elevated odds of absenteeism (aOR 1.19, 95% CI 1.10-1.29) and lower grades (β = -0.39, 95% CI -0.46 to -0.32). Similar results were found for students who ever used tobacco and cannabis.

CONCLUSIONS

California youth who co-use tobacco and cannabis were most likely to have absenteeism and lower grades. Comprehensive efforts to prevent or reduce youth substance use may improve educational outcomes.

Exploring Native Hawaiian and Pacific Islander Youths' E-Cigarette Resistance Strategies: Implications for Tobacco Product Use Prevention

This study examined the e-cigarette and vaping resistance strategies used by Native Hawaiian and Pacific Islander (NHPI) youths in rural Hawai'i. Focus groups (N = 17) were conducted in eight geographically dispersed elementary, middle/intermediate, and multilevel schools in low-income communities on Hawai'i Island. Sixty-nine youths (67% NHPI, Mage = 12.5 years) participated in this study. The resistance strategies discussed across the greatest number of groups were "refuse" (saying no), "explain" (providing reasons for vaping refusal), "avoid" (avoiding people or places where e-cigarettes were used), and "leave" (walking away from a situation where e-cigarettes were being used). Participants described the challenges in using these strategies within contexts characterized by widespread peer and family vaping and strong social demands to use e-cigarettes. The findings suggest the need for multi-level interventions based on youths' resistance strategies to meaningfully reduce youth vaping use in rural and/or NHPI communities.

Chronic disease as a risk factor for cigarette and e-cigarette use from young adulthood to adulthood

Chronic disease prevalence in young adults is increasing with 15-20 % reporting 1 or more chronic diseases. This study examined cross-sectional and prospective relationships between chronic disease and e-cigarette/cigarette use from young adulthood to adulthood utilizing the U.S.- based National Longitudinal Study of Adolescent to Adult Health (Add Health). Add Health Study wave 3 (2001-2002; ages 18-26), wave 4 (2008; ages 24-34), and wave 5 (2016-2018; ages 33-44) were used. Past 30-day cigarette use at waves 3-5 and past 30-day e-cigarette use at wave 5 were assessed. Two measures of chronic disease were used: asthma (yes/no) and non-asthmatic chronic disease (yes/no) composed of 7 additional chronic diseases (diabetes, migraine, heart problem, hepatitis B/C, high blood pressure, epilepsy, and cancer). Weighted multilevel logistic regression (controlling for age, race/ethnicity, gender, and education) was used to assess cross-sectional associations at wave 3, and then prospective associations of wave 3 chronic disease (asthma and non-asthmatic) with waves 4 and 5 cigarette and wave 5 e-cigarette use. Logistic regressions showed no significant cross-sectional or prospective relationships between asthma and cigarette and e-cigarette use. However, wave 3 non-asthmatic chronic disease was significantly associated with wave 4 cigarette use (aOR 1.38, p <.001, 95 % CI: 1.15, 1.65) and with wave 5 cigarette use (aOR 1.49, p <.001, 95 % CI: 1.21, 1.84) but not e-cigarette use. The association between chronic disease in young adulthood and tobacco use in adulthood differed by type of chronic disease and tobacco product, indicating the need for targeted interventions.

Association between e-cigarette use and asthma among US adolescents: Youth Risk Behavior Surveillance System 2015-2019

BACKGROUND

Previous studies have suggested that e-cigarette use, which has increased rapidly among US adolescents, may cause respiratory distress. This cross-sectional study aimed to investigate the factors associated with e-cigarette use and the relationship between e-cigarette use and asthma among US adolescents.

METHODS

Data from the Youth Risk Behavior Surveillance System between 2015 and 2019 were analyzed, and multivariable logistic regression was used to identify demographic and behavioral factors associated with e-cigarette use. Stratified analyses were conducted to assess the relationship between e-cigarette use and asthma among adolescents by previous combustible product use.

RESULTS

This study found that Hispanic adolescents had lower odds of e-cigarette use than White adolescents in Texas, with factors such as age, substance use, and depression being associated with use. In the US, male gender, previous combustible and substance use, and depression were associated with higher odds of ever using e-cigarettes, while current use was associated with several factors including age and White race. E-cigarette use was significantly associated with asthma among adolescents who have never used combustible products in both Texas and the entire US after adjusting for covariates (OR 1.32, 95% CI 1.06-1.66 and OR 1.18, 95% CI 1.02-1.37, respectively).

CONCLUSION

The findings from this study can be used to inform public health strategies and policies aimed at reducing e-cigarette use and its associated health risks among adolescents.

Longitudinal Association Between Exclusive and Dual Use of Cigarettes and Electronic Nicotine Delivery Systems and Asthma Among U.S. Adolescents

PURPOSE

Electronic Nicotine Delivery Systems (ENDS) use among adolescents has increased greatly over the past decade, but its impact on chronic respiratory health conditions, like asthma, is not fully understood.

METHODS

We examined data from Waves 1-5 (2013-2019) of the Population Assessment of Tobacco and Health Study using discrete time hazard models to analyze the association between time-varying tobacco product use and incident diagnosed asthma among adolescents aged 12-17 years at baseline. We lagged the time-varying exposure variable by one wave and categorized respondents by current use status (1+ days in the past 30 days): never or non-current, exclusive cigarette, exclusive ENDS, and dual cigarette and ENDS use. We also controlled for sociodemographic (age, sex, race/ethnicity, parental education) and other risk factors (urban/rural setting, secondhand smoke exposure, household combustible tobacco use, body mass index).

RESULTS

At baseline, over half the analytic sample (n = 9,141) was 15-17 years old (50.4%), female (50.2%), and non-Hispanic White (55.3%). Adolescents who exclusively smoked cigarettes had a statistically significant higher risk of incident diagnosed asthma at follow-up (adjusted Hazard Ratio (aHR): 1.68, 95% confidence interval (CI): 1.21-2.32) compared to those not currently using cigarettes or ENDS, but adolescents using ENDS exclusively (aHR: 1.25, 95% CI: 0.77-2.04) or in combination with cigarettes (aHR: 1.54, 95% CI: 0.92-2.57) did not.

DISCUSSION

Short-term exclusive cigarette use was associated with a higher risk of incident diagnosed asthma over five years of follow-up among adolescents. We did not find conclusive evidence for an association between exclusive ENDS or dual use and incident diagnosed asthma.

Ethnic differences in respiratory disease for Native Hawaiians and Pacific Islanders: Analysis of mediation processes in two community samples

OBJECTIVE

The prevalence of asthma and chronic obstructive pulmonary disorder (COPD) is elevated for Native Hawaiians but the basis for this differential is not well understood. We analyze data on asthma and COPD in two samples including Native Hawaiians Pacific Islanders, and Filipinos to determine how ethnicity is related to respiratory disease outcomes.

METHODS

We analyzed the 2016 and 2018 Behavioral Risk Factor Surveillance Survey (BRFSS), a telephone survey of participants ages 18 and over in the State of Hawaii. Criterion variables were a diagnosis of asthma or COPD by a health professional. Structural equation modeling tested how five hypothesized risk factors (cigarette smoking, e-cigarette use, second-hand smoke exposure, obesity, and financial stress) mediated the ethnic differential in the likelihood of disease. Age, sex, and education were included as covariates.

RESULTS

Structural modeling with 2016 data showed that Native Hawaiian ethnicity was related to higher levels of the five risk factors and each risk factor was related to a higher likelihood of respiratory disease. Indirect effects were statistically significant in almost all cases, with direct effects to asthma and COPD also observed. Mediation effects through comparable pathways were also noted for Pacific Islanders and Filipinos. These findings were replicated with data from the 2018 survey.

CONCLUSIONS

Native Hawaiian and Pacific Islander ethnicity is associated with greater exposure to five risk factors and this accounts in part for the ethnic differential in respiratory disease outcomes. The results support a social-ecological model of health disparities in this population. Implications of the findings for preventive interventions are discussed.

Associations for subgroups of E-cigarette, cigarette, and cannabis use with asthma in a population sample of California adolescents

Knowledge about the respiratory health consequences of adolescents' use of tobacco products with cannabis remains limited. We studied whether e-cigarettes, combustible cigarettes, and cannabis were independently associated with asthma in a population-based sample of 150,634 public high school students (10th and 12th graders), drawn in a two-stage design to be representative of the state of California in 2019-2020. Measures were obtained for use of e-cigarettes, combustible cigarettes, and cannabis; motives for use (three substances); method of use (for cannabis); ever being diagnosed with asthma; and having an asthma attack in past 12 months. Cross-classification indicated Nonuse for 64% of the sample; 15% Dual E-cigarette/Cannabis Use; 10% Exclusive Cannabis Use; 5% Exclusive E-cigarette Use; and 5% Triple Use. Multinomial logistic regression with a three-level criterion variable, controlling for age, sex, parental education, race/ethnicity, and three types of household use showed that compared with Nonuse, odds of Lifetime Asthma (vs. Never Had) was elevated for Triple Use (AOR = 1.14, CI 1.06-1.24), Dual E-cigarette/Cannabis Use (1.17, 1.12-1.23), Exclusive Cannabis Use (1.17, 1.11-1.23), and Exclusive E-cigarette Use (1.10, 1.02-1.18). Similar results were noted for Recent Asthma. Among persons who had used cannabis, 88% of the Triple group and 74% of the Dual E-cigarette/Cannabis group reported both smoking and vaping cannabis. Thus, co-occurrence of e-cigarette and cannabis use was a common pattern among adolescents in this study, and subgroups of cannabis and e-cigarette use showed similar associations with asthma. Preventive approaches should highlight the health implications of exclusive or combined e-cigarette and cannabis use.

E-cigarette effects on vascular function in animals and humans

Smoking tobacco cigarettes is a significant (cardiovascular) health risk factor. Although the number of tobacco cigarette users declined over the last decades, shisha smoking and e-cigarette vaping partially compensated for this health benefit. E-cigarettes may create highly addicted dual users (vaping and smoking). E-cigarettes seem not to represent a healthier alternative to tobacco smoking, although they may be less harmful. E-cigarette vaping causes oxidative stress, inflammation, endothelial dysfunction, and associated cardiovascular sequelae. This is primarily due to a significant overlap of toxic compounds in the vapor compared to tobacco smoke and, accordingly, a substantial overlap of pathomechanistic features between vaping and smoking. Whereas the main toxins in vapor are reactive aldehydes such as formaldehyde and acrolein, the toxic mixture in smoke is more complex, comprising particulate matter, reactive gases, transition metals, volatile organic compounds, and N-nitrosamines. However, it seems that both lifestyle drugs impair endothelial function to a quite similar extent, which may be due to the role of oxidative stress as the central pathomechanism to mediate endothelial dysfunction and vascular damage. Finally, the main selling argument for e-cigarette use that they help to quit smoking and get rid of nicotine addiction may be false because it seems that e-cigarettes instead trigger the opposite-younger entrance age and more frequent use. With our review, we summarize the adverse health impact of tobacco cigarettes and e-cigarettes, emphasizing the detrimental effects on endothelial function and cardiovascular health.

Association between electronic cigarettes use and whole blood cell among adults in the USA-a cross-sectional study of National Health and Nutrition Examination Survey analysis

Electronic cigarettes (E-cigarettes) use is an emerging public health problem. Trying to assess the independent associations between E-cigarettes use and whole blood cell in a nationally representative sample of the US adults is very important for the smoking population. Using E-cigarettes data from NHANES (National Health and Nutrition Examination Survey) 2013-2018, 17,180 adults were included in this cross-sectional analysis. All participants were stratified into four different groups (non-smoke group N=10087, E-cigarettes group N=52, dual-smoke group N=249, cigarettes group N=6792) based on questions SMQ020 (smoked at least 100 cigarettes in life) and SMQ690H (used last 5 days E-cigarettes). Whole blood cell tests included white blood cell (WBC) with differentials, red blood cell (RBC) with characteristics, and platelet variables. With adjusted by age, gender, and race ethnicity, multivariate logistic regression analyses were used to assess independent associations between E-cigarettes group and other groups for different whole blood cell variables. A total of 17,180 participants were included in the study; 47.9% were males, with a mean age of 46.99 (±0.29). In WBC-related variables, non-smoke group had the lowest value in WBC counts (7.15±0.05), lymphocyte (2.15±0.02), and monocyte (0.57±0.01), among the four different groups. In RBC-related variables, non-smoke group had the lowest value in mean cell volume (MCV, 88.46±0.14, p<0.05) and mean cell hemoglobin (MCH, 29.73±0.06, p<0.05), among the four different groups. In adjusted analysis, WBC (OR = 0.97, 95% CI: 0.96-0.98, p<0.001), especially lymphocyte (OR = 0.97, 95% CI: 0.96-0.98, p<0.001) and monocyte (OR = 0.11, 95% CI: 0.02-0.66, p<0.001) of non-smoke group, showed negative significant effect for E-cigarettes group. Meanwhile, lower odds of MCV (OR = 0.91, 95% CI: 0.81-1.04, p<0.05) and MCH (OR = 0.81, 95% CI: 0.65-1.00, p<0.05) in non-smoke group were observed compared to E-cigarettes group. Conversely, for dual-smoke group and cigarette group, there was no significant results in all whole blood cell variables compared to E-cigarettes group. E-cigarettes use might be associated with a systemic response that could lead to an increase in WBC, especially lymphocytes and monocytes, in the US adults. Meanwhile, the properties of RBC might also be influenced simultaneously; MCV and MCH in E-cigarettes population were bigger than the non-smoke population.

The Health Effects of Real-World Dual Use of Electronic and Conventional Cigarettes versus the Health Effects of Exclusive Smoking of Conventional Cigarettes: A Systematic Review

BACKGROUND

A high prevalence of dual use of e-cigarettes and conventional cigarettes has been reported across the world.

METHODS

A systematic search was carried out. We included original articles on any topic relevant to health, excluding mental health, in all languages. The PRISMA guidelines were followed. Both reviewers independently screened and read all publications. We compared dual use with exclusive smoking of conventional cigarettes (ESCC).

RESULTS

Fifty-two publications (49 studies) were included. Thirteen papers/10 studies were prospective. There was great heterogeneity across studies. Many methodological weaknesses, such as inaccurate exposure measurement, lack of adjustment for former tobacco consumption, and lack of significance testing were identified. Most prospective studies found dual use to be at least as harmful as ESCC. The longest follow-up was six years. Most of the best available cross-sectional studies found dual use associated with the same and, in several studies, significantly higher risk of self-reported symptoms/disease than in ESCC. The intensity of cigarette smoking seems associated with worse health.

CONCLUSION

Existing studies indicate that dual use is at least as, or probably even more, harmful than ESCC. Due to the predominance of cross-sectional studies and the methodological weaknesses we judged the overall certainty of the evidence as "low certainty".

Tests for confounding with cigarette smoking in the association of E-cigarette use with respiratory disorder: 2020 National-Sample Data

Associations of e-cigarette use with respiratory disorder have been demonstrated but it has been unclear whether these are confounded by current or previous cigarette smoking. We address this question through studying different time frames for e-cigarette use and respiratory disorders in 2020 BRFSS data (N = 214,945). E-cigarette use and combustible cigarette smoking were classified into four categories: Participant never used either (Nonuse); used e-cigarettes/cigarettes but not in the past 30 days (Former Use), used in past 30 days on some days (Nondaily Use), or used past 30 days on all days (Daily Use). Contrasts for e-cigarette status and cigarette status (with nonuse as reference group) were entered with covariates in logistic regression with asthma or COPD as criterion. Stratified analyses of e-cigarette use were also performed for smokers and nonsmokers. In the total sample, results showed independent positive associations with both lifetime and current asthma for Former, Nondaily, and Daily e-cigarette use (mostly p < .0001) and the three cigarette indices. Significant positive associations with COPD were found for the three e-cigarette indices (p < .0001) and all the cigarette indices. Stratified analyses showed significant associations of e-cigarette use with respiratory disorder among nonsmokers as well as among smokers. We conclude that independent associations for former e-cigarette use (controlling for current/former smoking) and significant associations of e-cigarette use with respiratory disorder among nonsmokers indicate these associations are not confounded with cigarette smoking and suggest reverse causation is implausible. Findings for former use are discussed with reference to possible mechanisms including sensitization effects.

Asthma and Tobacco Smoking

Asthma is a prevalent chronic pulmonary condition with significant morbidity and mortality. Tobacco smoking is implicated in asthma pathophysiology, diagnosis, prognosis and treatment. Smokers display increased prevalence and incidence of asthma, but a causal association cannot be claimed using existing evidence. Second-hand smoking and passive exposure to tobacco in utero and early life have also been linked with asthma development. Currently, approximately one-fourth of asthma patients are smokers. Regular smokers with asthma might display accelerated lung function decline and non-reversible airflow limitation, making their distinction from chronic obstructive pulmonary disease patients challenging. Asthma patients who smoke typically have uncontrolled disease, as shown by increased symptoms, more exacerbations and impaired quality of life. On the other hand, smoking cessation improves lung function and asthma severity. Thus, asthma patients and their caregivers should be actively questioned about their smoking status at each medical encounter, and smoking cessation ought to be strongly encouraged both for patients with asthma and their close contacts. Smokers with asthma should be provided with comprehensive smoking cessation interventions on top of other anti-asthma medications.

Association Between E-Cigarettes and Asthma in Adolescents: A Systematic Review and Meta-Analysis

INTRODUCTION

Numerous studies have revealed the relationship between E-cigarettes and asthma but have shown inconsistent results. This study systematically evaluated the potential association between E-cigarette use and asthma in adolescents.

METHODS

PubMed, Embase (Ovid), Cochrane Library, and the China Biological Medicine Database were searched for relevant articles published between database inception and February 28, 2021. The quality of included studies was evaluated using the Agency for Healthcare Research and Quality assessment, and a quantitative meta-analysis was conducted to pool outcomes of ORs with 95% CIs.

RESULTS

A total of 10 cross-sectional studies incorporating a total of 483,948 participants were included. All the study participants were middle- and high-school students with a mean age of 15-16 years. The median prevalence of ever E-cigarette use was 11.2% (range=2.2%, 45%), and that of current use was 7.5% (range=2.7%, 25%). Overall, E-cigarette use was associated with significantly higher odds of having asthma (pooled OR=1.31, 95% CI=1.22, 1.42) than nonuse, and both current use (OR=1.36, 95% CI=1.26, 1.48) and ever use (OR=1.20, 95% CI=1.12, 1.28) showed similar associations.

DISCUSSION

This study shows that both current and ever E-cigarette use have significant associations with asthma in adolescents. This knowledge might provide potential evidence for developing primary prevention strategies and serve as a reference for public health policy.

E-cigarette disparities: Who are the targets?

The tobacco industry has a long history of promoting health disparities especially through targeted marketing campaigns. The disparities perpetuated by e-cigarettes are just becoming apparent. This article will focus on disparities in e-cigarette usage within the following categories of youth: racial or ethnic groups, sexual and gender minoritized individuals, adolescents with asthma, teens with disabilities, and those coping with mental health stresses. Millions of youth are still using e-cigarettes, and e-cigarette use is disproportionately impacting White youth, youth who identify at lesbian, gay and transgender, and youth with disabilities. In addition, this article highlights the timeline of key tobacco regulations and recommended actions to curb the e-cigarette epidemic.

Predictors of electronic cigarette use and its association with respiratory health and obesity in young adulthood in Sweden; findings from the population-based birth cohort BAMSE

Despite the growing popularity of electronic cigarettes (e-cigarettes) over the last decade, few epidemiological studies have examined the influence on respiratory health in young adulthood. The aim of this study was to identify factors associated with e-cigarette use in young adulthood in Sweden, and to examine associations between e-cigarette use and lung function, respiratory symptoms, and obesity. This cross-sectional study included 3055 young adults from Sweden and used questionnaire and clinical data obtained at age 22-25 years. The prevalence of current e-cigarette use was 3.9% (n = 120). Few participants reported daily (0.4%) or exclusive (0.8%) use of e-cigarettes. In a multivariable adjusted logistic regression model, e-cigarette use was significantly associated with male gender (OR:3.2; 95% CI:1.5-6.7) and cigarette smoking (OR:14.7; 95% CI:5.5-39.0 for daily smoking). Prevalence of cough (15.0% vs. 8.5%) and mucus production (22.3% vs. 14.8%) was significantly higher among e-cigarette users compared to non-users, while no difference in lung function was observed. In addition, the prevalence of overweight/obesity was higher among e-cigarette users compared to non-users (36.7% vs. 22.3% with BMI≥25 kg/m²). In conclusion, cigarette smokers and males used e-cigarette more often compared to females and non-cigarette smokers. Attention should be given to respiratory symptoms among e-cigarette users, although our results may be explained by the concurrent use of conventional cigarettes, as the group of exclusive e-cigarette users were too small to allow firm conclusions.

How E-cigarettes and vaping can affect asthma in children and adolescents

PURPOSE OF REVIEW

Electronic nicotine delivery systems such as e-cigarettes are commonly felt to be harmless devices when compared to traditional cigarettes. However, an increasing number of studies support the biological plausibility for the potential detrimental effects of vaping on the respiratory mucosa. To date, few human studies have been carried out on adult vapers showing a reduction in lung function testing, especially in those with asthma, whereas the effects of vaping on children and adolescents have not been elucidated so far.

RECENT FINDINGS

Several cross-sectional, national, population-based studies on large groups of adolescents have been carried out showing an association between vape exposure and self-reported asthma diagnosis and/or respiratory symptoms in this age group. The effects of second and third-hand exposure together with those of active and passive exposure in pregnancy, are almost completely unknown.

SUMMARY

This review outlines recent data on the potential effects of vaping on asthma, focusing on vape composition, reported effects on the respiratory mucosa, available data in adolescents, and reasons behind the current vaping epidemic. The evidence so far available both in animals and humans suggests that vaping is not harmless, and its exposure should be limited in children and adolescents, especially when affected by asthma.

Vaping in Asthmatic Adolescents: Time to Deal with the Elephant in the Room

Adolescence is a period characterized by developmental, psychological, and psychosocial alterations, with a major impact on youths’ attitudes and perceptions. Adolescents with asthma may not comply with treatment and may develop risky behaviors, including smoking, vaping, and other substance use, leading to unanticipated exacerbations and consequences. Vaping has become extremely popular in this age group, and studies have suggested that it has potential adverse effects on asthmatic airways. More well-designed studies are needed to confirm the initial worrying data, and action must be taken by both medical officers and health authorities to deal with the elephant in the room and curb the vaping pandemic. The aim of this paper is to provide a review of the current knowledge regarding the effect of vaping on adolescents with asthma and to propose actions to restrain this fast-growing trend.

E-Cigarette Toxicology

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

Marijuana smoking and asthma: a protocol for a meta-analysis

INTRODUCTION

Recent studies have raised the concern on the risk of asthma in marijuana smokers; however, the results remain controversial and warrant further investigation. With a growing number of marijuana smokers, examining the association between marijuana smoking and asthma and quantifying such association through meta-analysis have important implications for public health and clinical decision-making. In view of this, the present protocol aims to detail a comprehensive plan of meta-analysis on the association aforementioned. The findings are expected to strengthen the current knowledge base pertaining to the potential adverse effects of marijuana smoking on pulmonary health and to facilitate the development of prevention strategies for asthma.

METHODS AND ANALYSIS

The MEDLINE/PubMed, Web of Science and EMBASE databases will be searched systematically from inception to 1 September 2021 to retrieve the relevant observational studies focusing on the association between marijuana smoking and asthma. Both unadjusted and adjusted effect sizes, such as OR, relative risk, HR and the corresponding 95% CIs will be extracted for pooled analyses. Heterogeneity and publication bias across the included studies will be examined. The Newcastle-Ottawa Quality Scale will be used to assess the quality and risk of bias. Statistical software Review Manager V.5.3 and Stata V.11.0 will be used for statistical analyses.

ETHICS AND DISSEMINATION

Since no private and confidential patient data will be included in the reporting, approval from an ethics committee is not required. The results will be published in a peer-reviewed journal or disseminated in the relevant conferences. The study raises no ethical issue.

OSF REGISTRATION NUMBER

10.17605/OSF.IO/UPTXC.

E-cigarette use and adverse respiratory symptoms among adolescents and Young adults in the United States

E-cigarette use among adolescents and young adults has been associated with adverse respiratory symptoms, including symptoms of asthma and bronchitis. This investigation examined whether such associations differ by primary type of e-cigarette device used. This cross-sectional study included data from four study populations in California and Connecticut, United States, ages 13-21 years (N = 10,483), who self-reported their tobacco use behaviors and health status from 2018 to 2020. Adverse respiratory symptoms were grouped as bronchitis, asthma exacerbation, and shortness of breath. Associations with e-cigarette use were examined by frequency of e-cigarette use (regardless of device type) and most-frequently use device type in the past 30 days (pod, pen/tank, disposable, or mod). Multivariable modeling accounted for demographic variables and use of other tobacco and cannabis. Results were pooled at the study level via random-effects meta-analysis. Across the four studies, e-cigarette use >5 days/month versus never use was associated with bronchitic symptoms (summary odds ratio, sOR: 1.56; 95% confidence interval, CI: 1.37, 1.77) and shortness of breath (sOR: 1.68; 95% CI: 1.35, 2.08) but not statistically significantly with asthma exacerbations (sOR: 1.36; 95% CI; 0.95, 1.95). Among past 30-day e-cigarette users, associations with respiratory symptoms did not differ by device type. In these populations, e-cigarette use was positively associated with symptoms of bronchitis and shortness of breath, but adjusted odds of symptoms did not differ meaningfully by device type. These findings suggest that risk of these respiratory outcomes is elevated among more frequent e-cigarette users regardless of device type used.

Association between e-cigarette use and asthma: a systematic review and meta-analysis

OBJECTIVE

Increasing e-cigarette use combined with emerging evidence of their respiratory effects raises concerns about their potential impact on asthma prevalence. This review evaluates the most recent available evidence on the association of e-cigarette use and asthma world-wide.

METHODS

A literature search was performed in PubMed, Scopus, CINAHL, Cochrane Library, Web of Science and ProQuest in March 2021. This study was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) registered with PROSPERO (registration number: CRD42020211812).

STUDY SELECTIONS

Cross-sectional and cohort studies assessing the association between e-cigarette use and asthma were eligible for inclusion. Studies examining exacerbations in asthma symptoms and severity were excluded. The quality of the included studies was assessed using the Appraisal tool for Cross-Sectional Studies (AXIS).

RESULTS

Thirteen cross-sectional studies with the sample size of 1,039,203 met the eligibility criteria. Odds ratios were pooled using a random effects model. Pooled analysis found a significant association between current e-cigarette use and asthma (pOR = 1.36, 95% CI 1.21-1.52) and ever e-cigarette use and asthma (pOR = 1.24 95% CI 1.13-1.36).

CONCLUSION

Our review found that e-cigarette use and ever e-cigarette use are correlated with asthma. However, heterogeneity and inconsistencies between covariates limited the interpretation of the results. This warrants further studies to investigate any potential causal association between e-cigarette use and asthma. No funding was received for this systematic review.

Tobacco use disorder and the lungs

This narrative review provides a summary of the impact of tobacco smoking on the respiratory system and the benefits of smoking cessation. Tobacco smoking is one of the leading preventable causes of death world-wide and a major risk factor for lung cancer and chronic obstructive pulmonary disease. Smoking is also associated with an increased risk of respiratory infections and appears to be related to poorer outcomes among those with COVID-19. Non-smokers with second-hand smoke exposure also experience significant adverse respiratory effects. Smoking imposes enormous health- and non-health-related costs to societies. The benefits of smoking cessation, in both prevention and management of respiratory disease, have been known for decades and, to this day, cessation support remains one of the most important cost-effective interventions that health professionals can provide to people who smoke. Cessation at any age confers substantial health benefits, even in smokers with established morbidities. As other treatments for chronic respiratory disease advance and survival rates increase, smoking cessation treatment will become even more relevant. While smoking cessation interventions are available, the offer of these by clinicians and uptake by patients remain limited.

Electronic Cigarettes and Asthma: What Do We Know So Far?

Electronic cigarettes (EC) are a novel product, marketed as an alternative to tobacco cigarette. Its effects on human health have not been investigated widely yet, especially in specific populations such as patients with asthma. With this review, we use the existing literature in order to answer four crucial questions concerning: (1) ECs' role in the pathogenesis of asthma; (2) ECs' effects on lung function and airway inflammation in patients with asthma; (3) ECs' effects on asthma clinical characteristics in asthmatics who use it regularly; and (4) ECs' effectiveness as a smoking cessation tool in these patients. Evidence suggests that many EC compounds might contribute to the pathogenesis of asthma. Lung function seems to deteriorate by the use of EC in this population, while airway inflammation alters, with the aggravation of T-helper-type-2 (Th2) inflammation being the most prominent but not the exclusive effect. EC also seems to worsen asthma symptoms and the rate and severity of exacerbations in asthmatics who are current vapers, whilst evidence suggests that its effectiveness as a smoking cessation tool might be limited. Asthmatic patients should avoid using EC.

Toxicology of flavoring- and cannabis-containing e-liquids used in electronic delivery systems

Electronic cigarettes (e-cigarettes) were introduced in the United States in 2007 and by 2014 they were the most popular tobacco product amongst youth and had overtaken use of regular tobacco cigarettes. E-cigarettes are used to aerosolize a liquid (e-liquid) that the user inhales. Flavorings in e-liquids is a primary reason for youth to initiate use of e-cigarettes. Evidence is growing in the scientific literature that inhalation of some flavorings is not without risk of harm. In this review, 67 original articles (primarily cellular in vitro) on the toxicity of flavored e-liquids were identified in the PubMed and Scopus databases and evaluated critically. At least 65 individual flavoring ingredients in e-liquids or aerosols from e-cigarettes induced toxicity in the respiratory tract, cardiovascular and circulatory systems, skeletal system, and skin. Cinnamaldehyde was most frequently reported to be cytotoxic, followed by vanillin, menthol, ethyl maltol, ethyl vanillin, benzaldehyde and linalool. Additionally, modern e-cigarettes can be modified to aerosolize cannabis as dried plant material or a concentrated extract. The U.S. experienced an outbreak of lung injuries, termed e-cigarette, or vaping, product use-associated lung injury (EVALI) that began in 2019; among 2,022 hospitalized patients who had data on substance use (as of January 14, 2020), 82% reported using a delta-9-tetrahydrocannabinol (main psychoactive component in cannabis) containing e-cigarette, or vaping, product. Our literature search identified 33 articles related to EVALI. Vitamin E acetate, a diluent and thickening agent in cannabis-based products, was strongly linked to the EVALI outbreak in epidemiologic and laboratory studies; however, e-liquid chemistry is highly complex, and more than one mechanism of lung injury, ingredient, or thermal breakdown product may be responsible for toxicity. More research is needed, particularly with regard to e-cigarettes (generation, power settings, etc.), e-liquids (composition, bulk or vaped form), modeled systems (cell type, culture type, and dosimetry metrics), biological monitoring, secondhand exposures and contact with residues that contain nicotine and flavorings, and causative agents and mechanisms of EVALI toxicity.

E-cigarette users are associated with asthma disease: A meta-analysis

BACKGROUND

At present, there are more than 300 million asthma patients in the world. Electronic cigarettes (e-cigarettes) are considered as a new way of smoking and are loved by young people. The relationship between e-cigarettes and asthma risk is still controversial. Therefore, we conducted a meta-analysis to explore the relationship between e-cigarettes and asthma.

METHODS

We searched PubMed, Embase, and Web of Science for research results published before august 2020. All data analysis was through R version 3.6.3. Publication bias was assessed using funnel plots, Begg's rank correlation test, and Egger regression asymmetry tests. Most of the included studies were adjusted for potential confounding factors.

RESULTS

This meta found the association of e-cigarette use with asthma, and the combined OR value was 1.27 (95% CI = 1.17-1.37). We found the significant association of current e-cigarette usage with asthma (OR = 1.30, 95% CI = 1.17-1.45), and the former use of e-cigarettes also had an association with asthma (OR = 1.22, 95% CI = 1.08-1.39). Then, when e-cigarettes were used in combination with traditional cigarettes, the association odds with asthma was 1.47 (95% CI = 1.13-1.91), which was higher than that of users who used traditional cigarettes (OR = 1.33, 95% CI = 1.19-1.49). In subgroup analysis, adult and female e-cigarette users were more closely associated with asthma.

CONCLUSION

In short, in this meta-analysis, we found that current or former use of e-cigarettes are associated with the prevalence of asthma. However, the specific relationship required more rigorous design for further verification.

The Association of Asthma, Sexual Identity, and Inhaled Substance Use among U.S. Adolescents

Rationale: Minority sexual identity appears to confer asthma risks. Although associations between inhaled substances and asthma are established, these have not been examined among sexual minority youths. Given sexual minority adolescents' disproportionately high rates of substance use, research is needed to fill this important gap.Objectives: Using a representative sample of adolescents from the United States, we 1) examined associations among asthma, sexual identity, and inhaled substance use and tested 2a) whether sexual identity moderates relationships between asthma and inhaled substance use and 2b) whether inhaled substance use mediates associations between sexual identity and asthma.Methods: Data are from the 2015 and 2017 Youth Risk Behavior Surveillance Survey. Adolescents (n = 30,113) reported if they were ever diagnosed with asthma, current use of cigarettes, cigars and/or cigarillos, marijuana, and electronic vapor products and if they ever used inhalants or synthetic marijuana. We used logistic regression to examine associations between asthma, sexual identity, and inhaled substance use controlling for age, race or ethnicity, and body mass index percentile, stratified by sex.Results: Lesbian, gay, and bisexual respondents had higher relative risks for asthma than heterosexual youth. Sexual minority female youths had significantly higher relative risks than heterosexual female youths for use of every inhaled substance. There were few sexual identity differences in inhaled substance use among male youths. Inhaled substance use was significantly associated with higher risks for asthma. In general, associations between each individual inhaled substance and asthma did not differ between sexual minority and heterosexual youths. However, when all inhaled substances were added into the models concurrently, inhaled substance use appeared to mediate associations with asthma among lesbian and bisexual female youths, and partially mediated these associations among sexual minority male youths.Conclusions: Sexual identity and inhaled substance use appear to play important roles in asthma risk. However, these variables do not fully explain the risk, suggesting that other unmeasured variables (e.g., stress and victimization) may be implicated in risks for both inhaled substance use and asthma. It is important that clinicians providing care to adolescents ask about sexual identity and inhaled substance use. Effective approaches to reducing inhaled substance use among adolescents, especially sexual minorities, are needed.

E-cigarette use and respiratory disorders: an integrative review of converging evidence from epidemiological and laboratory studies

Background

Use of electronic cigarettes (e-cigarettes) is prevalent among adolescents and young adults, but there has been limited knowledge about health consequences in human populations. We conduct a systematic review and meta-analysis of results on respiratory disorders from studies of general-population samples and consider the mapping of these results to findings about biological processes linked to e-cigarettes in controlled laboratory studies.

Method

We conducted a literature search and meta-analysis of epidemiological studies on the association of e-cigarette use with asthma and with COPD. We discuss findings from laboratory studies about effects of e-cigarettes on four biological processes: cytotoxicity, oxidative stress/inflammation, susceptibility to infection and genetic expression.

Results

Epidemiological studies, both cross-sectional and longitudinal, show a significant association of e-cigarette use with asthma and COPD, controlling for cigarette smoking and other covariates. For asthma (n=15 studies), the pooled adjusted odds ratio (aOR) was 1.39 (95% CI 1.28–1.51); for COPD (n=9 studies) the aOR was 1.49 (95% CI 1.36–1.65). Laboratory studies consistently show an effect of e-cigarettes on biological processes related to respiratory harm and susceptibility to illness, with e-cigarette conditions differing significantly from clean-air controls, although sometimes less than for cigarettes.

Conclusions

The evidence from epidemiological studies meets established criteria for consistency, strength of effect, temporality, and in some cases a dose–response gradient. Biological plausibility is indicated by evidence from multiple laboratory studies. We conclude that e-cigarette use has consequences for asthma and COPD, which is of concern for respirology and public health.

Epidemiological studies show a relationship of e-cigarette use with asthma and COPD, and laboratory studies show their adverse effects on four biological processes. It can be concluded that e-cigarette use is of significant concern for public health.https://bit.ly/3drH4pj

E-cigarette use and respiratory disorders: an integrative review of converging evidence from epidemiological and laboratory studies

BACKGROUND

Use of electronic cigarettes (e-cigarettes) is prevalent among adolescents and young adults, but there has been limited knowledge about health consequences in human populations. We conduct a systematic review and meta-analysis of results on respiratory disorders from studies of general-population samples and consider the mapping of these results to findings about biological processes linked to e-cigarettes in controlled laboratory studies.

METHOD

We conducted a literature search and meta-analysis of epidemiological studies on the association of e-cigarette use with asthma and with COPD. We discuss findings from laboratory studies about effects of e-cigarettes on four biological processes: cytotoxicity, oxidative stress/inflammation, susceptibility to infection and genetic expression.

RESULTS

Epidemiological studies, both cross-sectional and longitudinal, show a significant association of e-cigarette use with asthma and COPD, controlling for cigarette smoking and other covariates. For asthma (n=15 studies), the pooled adjusted odds ratio (aOR) was 1.39 (95% CI 1.28-1.51); for COPD (n=9 studies) the aOR was 1.49 (95% CI 1.36-1.65). Laboratory studies consistently show an effect of e-cigarettes on biological processes related to respiratory harm and susceptibility to illness, with e-cigarette conditions differing significantly from clean-air controls, although sometimes less than for cigarettes.

CONCLUSIONS

The evidence from epidemiological studies meets established criteria for consistency, strength of effect, temporality, and in some cases a dose-response gradient. Biological plausibility is indicated by evidence from multiple laboratory studies. We conclude that e-cigarette use has consequences for asthma and COPD, which is of concern for respirology and public health.

An update on controversies in e-cigarettes

E-cigarettes are electronic nicotine delivery systems (ENDS) which mimic tobacco smoking without the combustion of tobacco. These devices have been misleadingly marketed as "less harmful" alternatives to conventional smoking tobacco products. The e-liquid in e-cigarettes include nicotine, a humectant and other additives including flavourings, colourants, or adulterants such as bacterial and fungal products. In this review, we discuss the contrasting views of the tobacco lobby and most professional societies. We describe the epidemiology of the use of these devices, with a widespread and significant rise in youth e-cigarette use seen in both the USA and Europe. We also describe what is known about the toxicity and mechanisms of EVALI (e-cigarette or vaping associated lung injury). This characterised by respiratory failure with an intense inflammatory response. The presentations are diverse and clinicians should consider vaping as a possible cause of any unusual respiratory illness in patients who have a history of vaping or other use of e-cigarette-related products. Second hand exposure to e-cigarettes is also harmful through respiration and transdermal absorption. E-cigarettes have a worse acute toxicity than tobacco and their long-term toxicity is unknown, and we advocate for the immediate, most vigorous anti-vaping legislation possible.