A Problem for Generations: Impact of E-Cigarette Type on Immune Homeostasis

Chronic airway inflammatory diseases and e-cigarette use: a review of health risks and mechanisms

Chronic airway inflammatory diseases, which primarily include chronic obstructive pulmonary disease (COPD), asthma, allergic rhinitis, and chronic sinusitis, continue to have a high global prevalence, highlighting their significant public health impact. Concurrently, the use of e-cigarettes (tobacco e-cigarettes) has been rising worldwide, with many users perceiving them as a safer alternative to traditional cigarettes. However, accumulating evidence from international studies suggests that e-cigarettes pose substantial health risks. This review aims to explore recent research on the relationship between e-cigarette use and chronic airway inflammatory diseases. The findings indicate that e-cigarette usage increases the risk of developing these conditions. Specifically, studies have shown that e-cigarettes exacerbate airway inflammatory responses, elevate levels of type 2 inflammatory cytokines such as IL-4, IL-5, and IL-13, increase cellular oxidative stress, and impair lung function. These mechanisms may collectively contribute to an increased risk of chronic airway inflammatory diseases potentially associated with e-cigarette use.

Does Tobacco Smoking Affect Vaccine-Induced Immune Response? A Systematic Review and Meta-Analysis

Background. Causing approximately 8 million deaths each year, tobacco smoking represents a significant public health concern. Evidence shows that smoking significantly impairs antibody production and immune cell activity following vaccination. Objectives. This review aims to provide a comprehensive overview of the literature regarding how smoking reduces the effectiveness of active immunization by affecting vaccine-induced immune response. Methods. This study was performed according to the PRISMA guidelines, and the protocol was registered on the PROSPERO platform (ID: CRD42024582638). PubMed, Scopus and Web of Science were consulted as bibliographic and citation databases. Studies published in Italian and English and that aimed to investigate the effects of exposure to active and passive tobacco smoking on vaccine-induced immune response were included. Results. Thirty-four studies were selected. Overall, a decrease in antibody levels and avidity and in immune cell production were observed in individuals exposed to smoke. The meta-analysis showed a weighted mean difference between smokers and non-smokers equal to 0.65 (95% CI: 0.10-1.19, p = 0.02) for vaccinations against COVID-19, influenza, pneumococcus, HBV, HPV, tetanus, pertussis, polio, haemophilus influenzae type b, measles-mumps-rubella, and recurrent urinary tract infections. Conclusions. Smoking cessation campaigns should be considered in order to increase the effectiveness of vaccination programs. Furthermore, the opportunity to adopt different vaccine dosing schemes for smokers and non-smokers, especially in acute epidemics, should be considered.

Associations between ENDS and cigarette use, and compromised immunity in US adults: Findings from the 2021-2022 NHIS

BACKGROUND

Tobacco use presents increased risks for individuals with weakened immune systems (WIS). We investigated the association between cigarette and electronic nicotine delivery systems (ENDS or e-cigarettes) use and WIS in US adults using data from the 2021-2022 National Health Interview Survey.

METHODS

Data from 57,133 adults were analyzed, focusing on WIS prevalence due to health conditions, prescriptions, or both. Cigarette and ENDS use were categorized as never, former, or current. Weighted multivariable regression models adjusted for demographics and other health conditions to assess associations between tobacco use and WIS.

RESULTS

Among US adults, 4.3% had prescription-related WIS, 4.6% had health condition-related WIS, and 7% had WIS due to either reason. Adjusted results from multivariable regression models indicated that adults with WIS due to health conditions were more likely to be current (AOR = 1.21, 95%CI: 1.05-1.40) and former (AOR = 1.25, 95%CI: 1.11-1.39) cigarette smokers compared to counterparts without WIS. Adults with WIS due to prescriptions were more likely to be former cigarette smokers (AOR = 1.19, 95%CI: 1.06-1.34). Those with WIS for any reason were more likely to be current (AOR = 1.19, 95%CI: 1.05-1.35) and former (AOR = 1.24, 95%CI: 1.13-1.36) cigarette smokers. Adults with WIS due to health conditions (AOR = 1.23, 95%CI: 1.06-1.41) or any reasons (AOR = 1.19, 95%CI:1.05-1.34) were more likely to be former ENDS users compared to those without WIS.

CONCLUSIONS

In this nationally representative study, we found a notable link between cigarette and ENDS use with WIS, particularly among those with health condition-related or prescription-related WIS, underscoring the importance of addressing tobacco use in this vulnerable population.

Comparison of the effects of active and passive smoking of tobacco cigarettes, electronic nicotine delivery systems and tobacco heating products on the expression and secretion of oxidative stress and inflammatory response markers. A systematic review

OBJECTIVES

This work attempts to summarize current knowledge on the effects of active and passive smoking of cigarettes, electronic nicotine delivery systems and tobacco heating products on the expression and secretion of oxidative stress and inflammatory response mediators, and on their possible impact on chronic obstructive pulmonary disease development.

MATERIALS AND METHODS

The literature was searched by the terms: 'smoking', 'active smoking', 'passive smoking', 'main-stream smoke', 'side-stream smoke', 'secondhand smoke', 'cigarette' 'THP', 'tobacco heating product', 'ENDS', 'electronic nicotine delivery system', 'e-cigarette', 'electronic cigarette', oxidative stress', inflammatory response' and 'gene expression'.

RESULTS

Cigarette smoking (active and passive) induces oxidative stress and inflammatory response in the airways. We present the effect of active smoking of e-cigarettes (EC) and heat-not-burn (HnB) products on the increased expression and secretion of oxidative stress and inflammatory response markers. However, there is only a limited number of studies on the effect of their second-hand smoking, and those available mainly describe aerosol composition.

DISCUSSION

The literature provides data which confirm that active and passive cigarette smoking induces oxidative stress and inflammatory response in the airways and is a key risk factor of COPD development. Currently, there is a limited number of data about ENDS and THP active and passive smoking effects on the health of smokers and never-smokers. It is particularly important to assess the effect of such products during long-term use by never-smokers who choose them as the first type of cigarettes, and for never-smokers who are passively exposed to their aerosol.

Electronic nicotine delivery systems (ENDS): A convenient means of smoking?

Electronic nicotine delivery systems (ENDS), which are becoming increasingly popular in many parts of the world, have recently become more sophisticated in terms of their more active content and better controlled vaporisation. This review begins by describing how cigarette smoking led to the development of ENDS as a means of combatting nicotine addiction. ENDS are usually categorised as belonging to one of only three main generations, but a fourth has been added in order to differentiate the latest, most powerful, most advanced and innovative that have improved heating efficiency. Descriptions of the principal substances contained in ENDS are followed by considerations concerning the risk of toxicity due to the presence of albeit low concentrations of such a variety of compounds inhaled over a long time, and the increasingly widespread use of ENDS as a means of smoking illicit drugs. We also review the most widely used pharmacotherapeutic approaches to smoking cessation, and recent epidemiological data showing that ENDS can help some people to stop smoking. However, in order to ensure their appropriate regulation, there is a need for higher-quality evidence concerning the health effects and safety of ENDS, and their effectiveness in discouraging tobacco smoking.

The association between combustible/electronic cigarette use and stroke based on national health and nutrition examination survey

AIMS

This study aims to analyze the association between combustible/electronic cigarettes and the risk of stroke.

METHODS

We obtained data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES). The stroke history and combustible/electronic cigarette use were acquired by questionnaires. Considering the sole or dual use of combustible cigarettes and electronic cigarettes (e-cigarettes), we divided all the individuals into four subgroups, including nonsmokers (reference group), sole combustible cigarette, sole e-cigarette, and dual use of both combustible cigarettes and e-cigarettes. We performed multivariable logistic regression to determine the association between cigarette use with the prevalence of stroke. We used odds ratios (ORs) with 95% confidence intervals (CIs) to show the effect size. Finally, we developed a prediction model to evaluate the risk of stroke for individuals with combustible or electronic cigarette use based on a random forest model.

RESULTS

We included a total of 4022 participants in the study. The median age was 55, and 48.3% of the participants were males. When we adjusted for age, gender, education attainment, race, total-to-HDL cholesterol (< 5.9 or ≥ 5.9), diabetes, hypertension, and alcohol consumption, the groups of sole e-cigarette use, sole combustible cigarette use, and dual use of combustible and electronic cigarettes were significantly associated with the prevalence of stroke with ORs (with 95%CI) of 2.07 (1.04-3.81), 2.36 (1.52-3.59), 2.34 (1.44-3.68), respectively. In the testing set, the AUC was 0.74 (95%CI = 0.65-0.84), sensitivity was 0.68, and specificity was 0.75.

CONCLUSION

Sole e-cigarettes and dual use of e-cigarettes with combustible cigarettes might increase the risk of stroke.