Electronic cigarette (e-cigarette) use and frequency of asthma symptoms in adult asthmatics in California

Association between use of heated tobacco products and long-term respiratory effects considering smoking history: internet-based cross-sectional study in Japan

BACKGROUND

With the use of heated tobacco products (HTPs) becoming more widespread in Japan, interest in the health effects of HTP has grown. Since the majority of HTP users are former smokers, information about the user's smoking history and health status before HTP use is needed when assessing the health effects of HTP use. The limited epidemiological studies available did not consistently consider this information adequately, therefore we conducted a cross-sectional study investigating the association between HTP use and respiratory chronic diseases and symptoms.

METHODS

The questionnaires were sent to a research panel members in Japan via the Internet, and individuals who met the study criteria and were either current exclusive HTP users, current exclusive cigarette users or those had never used tobacco products were selected. Information about the participants' smoking history and health status before they used HTPs was obtained. The effects of participant smoking history before HTP use and the impacts on outcomes upon switching to HTP were assessed using a logistic regression model. The odds ratio (OR) for current exclusive HTP users relative to never tobacco users was calculated. The OR was calculated under two scenarios, one in which the smoking history was ignored or one in which the smoking history was considered.

RESULTS

Of the participants from whom responses to the questionnaires were obtained, 17,406 participants were included in the analysis. Almost all participating current exclusive HTP users had a history of long-term smoking (mean: 30.8 years), and the occurrence of outcomes both before and after the start using HTP was reported. The ORs, without adjustment and with adjustment for smoking history before HTP use were, 3.23 (95% CI: 1.37-7.61) and 1.85 (95% CI: 0.70-4.89) respectively in COPD, same as other outcomes.

CONCLUSIONS

These results suggest that smoking history before HTP using affects the occurrence of outcomes, and underscore the importance of considering smoking history when assessing the health effect of HTP use. Since the duration of HTP use is considerably shorter than that of cigarette use at present, further research, such as follow-up surveys assessing the long-term respiratory effects of HTP use, will be necessary.

Longitudinal association of exclusive and dual use of cigarettes and cigars with asthma exacerbation among US adults: a cohort study

BACKGROUND

Cigar use among adults in the United States has remained relatively stable in the past decade and occupies a growing part of the tobacco marketplace as cigarette use has declined. While studies have established the detrimental respiratory health effects of cigarette use, the effects of cigar use need further characterization. In this study, we evaluate the prospective association between cigar use, with or without cigarettes, and asthma exacerbation.

METHODS

We used data from Waves 1-5 (2013-2019) of the Population Assessment of Tobacco and Health Study to run generalized estimating equation models examining the association between time-varying, one-wave-lagged cigarette and cigar use and self-reported asthma exacerbation among US adults (18+). We defined our exposure as non-established (reference), former, exclusive cigarette, exclusive cigar, and dual use. We defined an asthma exacerbation event as a reported asthma attack in the past 12 months necessitating oral or injected steroid medication or asthma symptoms disrupting sleep at least once a week in the past 30 days. We adjusted for age, sex, race and ethnicity, household income, health insurance, established electronic nicotine delivery systems use, cigarette pack-years, secondhand smoke exposure, obesity, and baseline asthma exacerbation.

RESULTS

Exclusive cigarette use (incidence rate ratio (IRR): 1.26, 95% confidence interval (CI): 1.03-1.54) and dual use (IRR: 1.41, 95% CI: 1.08-1.85) were associated with a higher rate of asthma exacerbation compared to non-established use, while former use (IRR: 1.01, 95% CI: 0.80-1.28) and exclusive cigar use (IRR: 0.70, 95% CI: 0.42-1.17) were not.

CONCLUSION

We found no association between exclusive cigar use and self-reported asthma exacerbation. However, exclusive cigarette use and dual cigarette and cigar use were associated with higher incidence rates of self-reported asthma exacerbation compared to non-established use. Studies should evaluate strategies to improve cigarette and cigar smoking cessation among adults with asthma who continue to smoke.

Sex-specific lung inflammation and mitochondrial damage in a model of electronic cigarette exposure in asthma

The prevalence of electronic cigarette (EC) use among adult with asthma has continued to increase over time, in part due to the belief of being less harmful than smoking. However, the extent of their toxicity and the involved mechanisms contributing to the deleterious impact of EC exposure on patients with preexisting asthma have not been delineated. In the present project, we tested the hypothesis that EC use contributes to respiratory damage and worsening inflammation in the lungs of patients with asthma. To define the consequences of EC exposure in established asthma, we used a mouse model with/without preexisting asthma for short-term exposure to EC aerosols. C57/BL6J mice were sensitized and challenged with a DRA (dust mite, ragweed, Aspergillus fumigates, 200 µg/mL) mixture and exposed daily to EC with nicotine (2% nicotine in 30:70 propylene glycol: vegetable glycerin) or filtered air for 2 wk. The mice were evaluated at 24 h after the final EC exposure. After EC exposure in asthmatic mice, lung inflammatory cell infiltration and goblet cell hyperplasia were increased, whereas EC alone did not cause airway inflammation. Our data also show that mitochondrial DNA (mtDNA) content and a key mtDNA regulator, mitochondrial transcription factor A (TFAM), are reduced in asthmatic EC-exposed mice in a sex-dependent manner. Together, these results indicate that TFAM loss in lung epithelium following EC contributes to male-predominant sex pathological differences, including mitochondrial damage, inflammation, and remodeling in asthmatic airways.NEW & NOTEWORTHY Respiratory immunity is dysregulated in preexisting asthma, and further perturbations by EC use could exacerbate asthma severity. However, the extent of their toxicity and the involved mechanisms contributing to the deleterious impact of EC exposure on patients with preexisting asthma have not been delineated. We found that EC has unique biological impacts in lungs and potential sex differences with loss of TFAM, a key mtDNA regulator, in lung epithelial region from our animal EC study.

Healthcare utilisation and expenditures attributable to current e-cigarette use among US adults

AIMS

This study estimated annual healthcare expenditures attributable to current e-cigarette use among US adults, including current exclusive and dual/poly e-cigarette use.

METHODS

Analysing the 2015-2018 National Health Interview Survey data, we estimated the impacts of e-cigarette use on healthcare utilisation among adults aged 18+ years. Healthcare utilisation outcomes were hospital nights, emergency room (ER) visits, doctor visits and home visits. Current e-cigarette use was categorised as exclusive and dual/poly e-cigarette use. The econometric model included two equations: health status as a function of e-cigarette use and other independent variables, and healthcare utilisation as a function of health status, e-cigarette use, and other independent variables. Using an 'excess utilisation' approach, we multiplied the e-cigarette-attributable fraction derived from the model by annual health expenditures to calculate healthcare expenditures attributable to current exclusive and dual/poly e-cigarette use, the sum of which were expenditures attributable to all current e-cigarette use.

RESULTS

Current exclusive and dual/poly e-cigarette use, with 0.2% and 3.5% prevalence in 2015-2018, were associated with higher odds of reporting poor health status than never tobacco users. Poor health status was associated with higher odds of using the four healthcare services and a greater number of ER and doctor visits. Annual healthcare expenditures attributable to all current e-cigarette use was $15.1 billion ($2024 per user) in 2018, including $1.3 billion attributable to exclusive e-cigarette use ($1796 per user) and $13.8 billion attributable to dual/poly e-cigarette use ($2050 per user).

CONCLUSION

Adult current e-cigarette use was associated with substantial excess healthcare utilisation and expenditures.

Prevalence of active and passive smoking among asthma and asthma-associated emergency admissions: a nationwide prevalence survey study

Asthma affects 7% of children and 8% of adults in the United States. There is a paucity of studies examining the association between passive smoking and an increased risk of asthma exacerbations that led the authors to examine the association between various modes of smoking and rates of asthma exacerbations. A retrospective cross-sectional/case-control study was conducted using the National Health and Nutrition Examination Survey dataset (2013-2018). Out of 312,979 respondents, 35,758 (11.43%) had a history of asthma, 9083 (2.9%) had asthma attacks in the past year, and 4731 (1.51%) had asthma-related emergency room admissions in the past year. Prevalence of asthma-related emergency admissions were higher among active cigarette smoking (46.25 vs 35.46%), e-cigarette smoking (26.63 vs 16.07%), and passive smoking at home (37.53 vs 25.67%), workplace passive smoking (14.35 vs 12.11%), in bar (32.38 vs 26.16%), and car (26.21 vs 14.44%) (p < 0.0001). In multivariate regression analysis, we found regular cigarette smoking (OR 1.13, 95% confidence interval (CI) 1.009-1.260, p = 0.0252), e-cigarette (OR 2.13, 95% CI 1.92-2.36, p = 0.0043), cigar use (OR 1.21, 95% CI 1.1-1.33, p < 0.001), ultra-long cigarette length (OR 4.85, 95% CI 3.33-7.06, p < 0.0001), and passive smoking (OR 5.25, 95% CI 3.43-8.06, p < 0.0001) were associated with increased rates of asthma exacerbations over last 12 months. The study shows increased odds of asthma exacerbations among those using ultra-long cigarettes, e-cigarettes, and cigars. Consequently, passive inhalation from even a single smoker in the home, workplace, bars and cars is associated with worsening outcomes in asthma patients.

E-cigarettes and asthma in adolescents

PURPOSE OF REVIEW

E-cigarettes have been long purported to be a mechanism of harm reduction in current smokers. However, market expansion to adolescents has been aggressive, despite government interventions. Research examining the adverse effects of e-cigarettes in teens with asthma has been limited. We discuss the most recent data on the pulmonary manifestations of e-cigarettes use and exposure in adolescents with asthma.

RECENT FINDINGS

Adolescents with asthma are more likely to be e-cigarette users than those without asthma and more likely to have asthma exacerbations. Increased pulmonary inflammatory cytokines have been seen in e-cigarette users and mouse models. Yet, providers are not confident in e-cigarette screening and counselling despite acknowledging adolescents are using e-cigarettes regularly.

SUMMARY

Since the introduction of e-cigarettes into the United States market in 2007, adolescents use of these products has risen, even after a brief decline during the height of the COVID-19 pandemic. This review will describe the most recent studies on e-cigarette use trends, cytotoxicity of e-cigarette aerosol and associations with the diagnosis and symptoms of asthma. Knowledge gaps, advocacy efforts, evidence on e-cigarette cessation will be highlighted.

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-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.

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.