E-cigarette, or vaping, product use-associated lung injury: a review

Multidisciplinary approaches in electronic nicotine delivery systems pulmonary toxicology: emergence of living and non-living bioinspired engineered systems

Technology-based platforms offer crucial support for regulatory agencies in overseeing tobacco products to enhance public health protection. The use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes, has surged exponentially over the past decade. However, the understanding of the impact of ENDS on lung health remains incomplete due to scarcity of physiologically relevant technologies for evaluating their toxicity. This review examines the societal and public health impacts of ENDS, prevalent preclinical approaches in pulmonary space, and the application of emerging Organ-on-Chip technologies and bioinspired robotics for assessing ENDS respiratory toxicity. It highlights challenges in ENDS inhalation toxicology and the value of multidisciplinary bioengineering approaches for generating reliable, human-relevant regulatory data at an accelerated pace.

Impact of Smoking on Salivary Lipid Profile and Oxidative Stress in Young Adults: A Comparative Analysis between Traditional Cigarettes, E-Cigarettes, and Heat-Not-Burn Products

BACKGROUND Smoking nicotine is considered to be one of the most harmful addictions, leading to the development of a number of health complications, including many pathologies in the oral cavity. The aim of this study was to examine the effect of smoking traditional cigarettes, e-cigarettes, and heat-not-burn products on profiles of salivary lipids and lipid peroxidation products in the unstimulated and stimulated saliva of healthy young adults with a smoking habit of up to 3 years. MATERIAL AND METHODS We enrolled 3 groups of 25 smoking patients each and a control group matched for age, gender, and oral status. In saliva collected from patients from the study groups and participants from the control group, the concentrations of sphingolipids: sphingosine, sphinganine, sphingosine-1-phosphate, ceramides, and salivary lipid peroxidation products - malondialdehyde (MDA) and 4-hydroxynonenal (HNE) - were measured. The normality of distribution was assessed using the Shapiro-Wilk test. For comparison of the results, one-way analysis of variance (ANOVA) followed by post hoc Tukey test was used. RESULTS We demonstrated that each type of smoking causes a decrease in the concentration of salivary lipids, and there was an increased concentration of salivary MDA and 4-HNE. CONCLUSIONS Smoking in the initial period of addiction leads to an increase in the concentration of lipid peroxidation products through increased oxidative stress, leading to disturbance of the lipid balance of the oral cavity (eg, due to damage to cell membranes).

Exploring the Rise of E-cigarette Use Among Male Adolescents in Al-Ahsa, Saudi Arabia: Prevalence, Patterns, and Influencing Factors

BACKGROUND

The rising prevalence of electronic cigarette (E-cigarette) use among adolescents is a major public health concern. This study investigates the prevalence of E-cigarette use among male adolescents in Al-Ahsa, Saudi Arabia, and explores associated factors.

METHODOLOGY

A cross-sectional study was conducted from December 2022 to April 2023, involving 476 male students aged 12 to 19. Data were collected through structured questionnaires, covering sociodemographic information, E-cigarette usage patterns, reasons for use, sources of acquisition, awareness of nicotine content, and perceptions of harm. Statistical analysis was performed using SPSS 25 (IBM Corp., Armonk, NY), with significance set at p < 0.05.

RESULTS

The study revealed a prevalence of 17.4% E-cigarette use among participants, with 12.6% using E-cigarettes exclusively and 4.8% concurrently with traditional tobacco cigarettes. Key findings included initiation as early as age eight, sustained and frequent use, and motivations including peer influence (61.4%), curiosity (31.3%), and flavored options (26.5%). Online platforms (34.9%) and shopping malls (28.9%) were the primary sources of E-cigarette acquisition. Most participants were aware of the nicotine content (84.3%) and believed E-cigarettes were harmful (86.7%). Importantly, 69.9% expressed intentions to quit, with 44.6% planning to do so within 30 days. Significant associations were found between E-cigarette use, education level, and having friends who smoke.

CONCLUSION

This study highlights the prevalence of E-cigarette use among male adolescents in Al-Ahsa, Saudi Arabia, and identifies peer influence, curiosity, and appealing flavors as driving factors. Targeted prevention and intervention programs, along with regulatory efforts to restrict access, are urgently needed to address this growing public health issue. Increasing awareness of E-cigarette risks and providing cessation support are vital steps towards mitigating E-cigarette use among Saudi male adolescents.

The Emerging Cloud: a survey of vapers, their health and utilization of healthcare within the UK

BACKGROUND

Recent work in the UK estimated the prevalence of current cannabinoid-based vaping to be higher than in the USA, a factor previously associated with e-cigarette or vaping-associated lung injury (EVALI). Research in the USA has demonstrated that attendances to emergency departments relating to e-cigarettes began to rise before the EVALI outbreak, suggesting that vapers also experience milder forms of vaping-related illness.

AIM

Quantify symptom prevalence and healthcare utilization amongst current UK vapers.

DESIGN

Voluntary online survey of individuals aged 16 and over within the UK.

METHODS

Anonymized data were collected on demographics, vaping/smoking status and vaping substances used. Current vapers were asked about the presence of 10 prevalent symptoms from previous US EVALI case series, healthcare attendances and diagnoses given. Risk-ratios were calculated to compare the likelihood of symptoms and attendances between substances.

RESULTS

A total of 2477 complete responses were analysed. In all, 397 respondents were current vapers. Symptom prevalence within the previous 12 months ranged from 3.8% to 30.5% (bloody sputum, cough). Healthcare attendances per symptomatic respondent ranged from 0.1 to 1.4 (bloody sputum, shortness of breath). Current vapers of cannabinoid-based products (alone/in combination) had the most attendances per symptomatic respondent for 9/10 symptoms and were more likely to report symptoms aside from 'cough' (nicotine-free e-liquids [risk ratio = 1.7]). Clinicians reportedly never diagnosed vaping-related illness.

CONCLUSIONS

UK vapers experience symptoms previously reported in EVALI cases for which they also seek healthcare. Users of cannabinoid-based products were more likely to report symptoms and accounted for a higher healthcare burden. UK vapers may also experience vaping-related illness that does not meet EVALI case criteria.

Sex Differences in E-Cigarette Use and Related Health Effects

BACKGROUND

Electronic cigarettes (e-cigarettes) comprise a variety of products designed to deliver nicotine, flavorings, and other substances. To date, multiple epidemiological and experimental studies have reported a variety of health issues associated with their use, including respiratory toxicity, exacerbation of respiratory conditions, and behavioral and physiological effects. While some of these effects appear to be sex- and/or gender-related, only a portion of the research has been conducted considering these variables. In this review, we sought to summarize the available literature on sex-specific effects and sex and gender differences, including predictors and risk factors, effects on organ systems, and behavioral effects.

METHODS

We searched and selected articles from 2018-2023 that included sex as a variable or reported sex differences on e-cigarette-associated effects.

RESULTS

We found 115 relevant studies published since 2018 that reported sex differences in a variety of outcomes. The main differences reported were related to reasons for initiation, including smoking history, types of devices and flavoring, polysubstance use, physiological responses to nicotine and toxicants in e-liquids, exacerbation of lung disease, and behavioral factors such as anxiety, depression, sexuality, and bullying.

CONCLUSIONS

The available literature supports the notion that both sex and gender influence the susceptibility to the negative effects of e-cigarette use. Future research needs to consider sex and gender variables when addressing e-cigarette toxicity and other health-related consequences.

E-cigarette and Vaping-Induced Lung Injury (EVALI) Long Taken for Miliary Tuberculosis: A Rare Cause of Interstitial Lung Disease

Electronic cigarettes, a recent and burgeoning product, are gaining traction among the general population. However, despite their growing popularity, there is a lack of comprehensive research on their potential health risks. A prominent concern is EVALI (electronic cigarette or vaping product use-associated lung injury), a newly recognized condition currently under intense investigation. Here, we report the case of a 24-year-old male with a history of chronic smoking e-cigarettes and vaping products heavily over the past year. He sought urgent care at the emergency room due to symptoms that had been present for seven days before seeking medical attention. These symptoms included a sudden onset of difficulty breathing at rest, an intermittent dry cough producing a small amount of greenish sputum, and occasional episodes of mild hemoptysis. Chest radiograph showed bilateral diffuse infiltrates including almost innumerable tiny interstitial nodules. Multiple lobes of the lungs were affected by consolidations and patches of ground-glass opacities in the chest high-resolution computed tomography (HRCT) image. Throughout the following week, the patient's health showed gradual improvement with the aid of supportive measures and corticosteroid treatment. As part of the recovery plan, the patient was released with a gradually reducing regimen of oral corticosteroids and was scheduled for regular outpatient monitoring. The progression of the recovery was notable through enhancements in clinical symptoms, biological markers, and radiological findings.

The implications of Vitamin E acetate in E-cigarette, or vaping, product use-associated lung injury

In the summer of 2019, a cluster of cases were observed with users of battery-operated or superheating devices presenting with multiple symptoms, such as dyspnea, cough, fever, constitutional symptoms, gastrointestinal upset, and hemoptysis, that is now termed e-cigarette, or vaping, product use-associated lung injury (EVALI). The Centers for Disease Control and Prevention reported 2807 cases within the USA leading to at least 68 deaths as of February 18, 2020. The heterogeneous presentations of EVALI make diagnosis and treatment difficult; however, treatment focused on identifying and removal of the noxious substance and providing supportive care. Vitamin E acetate (VEA) is a likely cause of this lung injury, and others have reported other components to play a possible role, such as nicotine and vegetable glycerin/propylene glycol. EVALI is usually observed in adolescents, with a history of vaping product usage within 90 days typically containing tetrahydrocannabinol, and presenting on chest radiograph with pulmonary infiltrates or computed tomography scan with ground-glass opacities. Diagnosis requires a high degree of suspicion to diagnose and exclusion of other possible causes of lung disease. Here, we review the current literature to detail the major factors contributing to EVALI and primarily discuss the potential role of VEA in EVALI. We will also briefly discuss other constituents other than just VEA, as a small number of EVALI cases are reported without the detection of VEA, but with the same clinical diagnosis.

One Acute Exposure to E-Cigarette Smoke Using Various Heating Elements and Power Levels Induces Pulmonary Inflammation

Background

Electronic cigarettes (eC) may not be entirely benign. There is a lack of data on the effect of a single acute exposure of eC vapor using various heating sources and power settings upon lung injury. The purpose of this study was to determine if an acute exposure with eC vapor heated with different heating elements and power levels induced inflammatory changes in the lungs and heart.

Methods

Rats were exposed to pure air or received a single, 4-h exposure to eC vapor. The devices used either a stainless steel (SS) or nichrome (NC) heating element randomized to a low or high atomization power (45 versus 70 W). Rats were euthanized within 48 h of exposure.

Results

The eC groups showed accumulation of inflammatory cells in bronchial lumen, near the pleura, and within the alveolar spaces. The numbers of inflammatory cells per field in the lung parenchyma were significantly greater in the rats exposed to eC groups vs. the air group. There were significantly higher inflammatory gene expression changes in the lungs of animals assigned to 70 W power. We observed that eC vapor generated using burnt coils were toxic and could cause acute respiratory distress and myocarditis.

Conclusion

In conclusion, one 4-h exposure to eC vapor, in the absence of vitamin E oil or nicotine, significantly increased lung inflammation. Effects were seen after exposures to vapor generated using SS and NC heating elements at either high or low power. Vapor from devices with burnt coils can negatively affect the heart and lung.

Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways

Background

Electronic cigarettes (e-cigarettes) are used worldwide as a substitute for conventional cigarettes. Although they are primarily intended to support smoking cessation, e-cigarettes have been identified as a gateway to smoking habits for young people. Multiple recent reports have described the health effects of inhaling e-cigarettes. E-cigarette liquid (e-liquid) is mainly composed of propylene glycol (PG) and glycerol (Gly), and the aerosol generated by these devices primarily contains these two components. Thus, this study aimed to evaluate the effects of PG and Gly on human small airway epithelial cells (SAECs).

Methods

SAECs were exposed to PG or Gly, and cell proliferation, cell viability, lactate dehydrogenase (LDH) release, DNA damage, cell cycle, and apoptosis were evaluated. Additionally, SAECs derived from chronic obstructive pulmonary disease (COPD) patients (COPD-SAECs) were investigated.

Results

Exposure of SAECs to PG significantly inhibited proliferation (1%, PG, p = 0.021; 2–4% PG, p < 0.0001) and decreased cell viability (1–4% PG, p < 0.0001) in a concentration-dependent manner. Gly elicited similar effects but to a reduced degree as compared to the same concentration of PG. PG also increased LDH release in a concentration-dependent manner (3% PG, p = 0.0055; 4% PG, p < 0.0001), whereas Gly did not show a significant effect on LDH release. SAECs exposed to 4% PG contained more cells that were positive for phosphorylated histone H2AX (p < 0.0001), a marker of DNA damage, and an increased proportion of cells in the G1 phase (p < 0.0001) and increased p21 expression (p = 0.0005). Moreover, caspase 3/7-activated cells and cleaved poly (ADP-ribose) polymerase 1 expression were increased in SAECs exposed to 4% PG (p = 0.0054). Furthermore, comparing COPD-SAECs to SAECs without COPD in PG exposure, cell proliferation, cell viability, DNA damage and apoptosis were significantly greater in COPD-SAECs.

Conclusion

PG damaged SAECs more than Gly. In addition, COPD-SAECs were more susceptible to PG than SAECs without COPD. Usage of e-cigarettes may be harmful to the respiratory system, especially in patients with COPD.

Association between electronic nicotine delivery systems (ENDS) device and E-liquid alterations and flavor use with clinical and EVALI-like symptoms

Studies reporting clinical symptoms related to electronic nicotine delivery systems (ENDS) usage, especially types of devices and e-liquids, are sparse. The sample included 1,432 current ENDS users, ages 18-64, from a nationwide online survey conducted in 2016. ENDS use included device types, nicotine content, flavors, and e-liquid used. Outcomes included any e-cigarette, or vaping, product use-associated lung injury (EVALI)-like symptoms (e.g., cough, shortness of breath, nausea) as well as any clinical symptoms. Of the sample, 50% were female, 23% non-Hispanic (NH) White, 23% NH Black, 54% Hispanic, 18% aged 18-24, 17% LGBTQ, 41% with <$50 K income, 55% 1 + any symptoms, and 33% 1 + any EVALI-like symptoms. Cough and nausea were most prevalent among EVALI-like symptoms (27% and 7.3%, respectively). The proportion having any EVALI-like symptoms was higher in the following groups: younger, Hispanic, current smokers, and current other product users. With multiple adjustments, participants who used refillable devices, varied nicotine content, used flavored products, or made their own e-liquids were more likely to have clinical symptoms than their counterparts. For example, the odds (95% CI) of having 1 + EVALI-like symptoms in participants who used refillable devices with e-liquid pour or e-liquid cartridge replacement were 1.70 (1.13, 2.56) and 1.95 (1.27, 2.99), respectively, compared to the non-refillable group. Use of products (devices and e-liquids) that can be altered and flavored products are associated with higher odds of having clinical symptoms, including EVALI-like symptoms.

Crazy vaping and crazy-paving, a case of E-Cigarette/Vaping-Associated Lung Injury (EVALI) with chest CT showing crazy-paving pattern

E-cigarettes are devices that generate an aerosol by heating a fluid containing multiple chemicals, such as nicotine, additives, and flavorings. They were developed to aid in smoking cessation and were promoted as socially acceptable, healthier, cheaper than conventional cigarettes. Multiple lung disorders related to e-cigarette use are reported, and they range from mild cases of pneumonitis to life-threatening lung disorders that may require intubation and mechanical ventilation. Most of the complications are due to the generation of various unknown and potentially harmful chemicals within the aerosol generated in the e-cigarette. These disorders are known collectively as e-cigarette/Vaping-associated lung injury (EVALI). E-cigarettes are marketed as safer alternatives to traditional cigarettes, with the highest rates of use are noted in young smokers. Given the significant prevalence of e-cigarettes use and their pulmonary complications, EVALI should be considered a potential etiology in the broad differential diagnosis of patients with pulmonary disease and a history of vaping. Herein, we present a case of cryptogenic organizing pneumonia with a chest C.T. showing a crazy-paving pattern in a patient with a history of vaping.

Electronic Cigarette Exposure Enhances Lung Inflammatory and Fibrotic Responses in COPD Mice

Although a few studies show that the use of electronic nicotine delivery systems (ENDS) may ameliorate objective and subjective outcomes in COPD smokers who switched to electronic cigarettes, it is unclear whether e-cigarette exposure alters lung pathological features and inflammatory response in COPD. Here, we employed βENaC-overexpressing mice bearing COPD-like pulmonary abnormality, and exposed them to ENDS. We found that ENDS exposure aggravated airspace enlargement and mucus production in βENaC-overexpressing mice, which was associated with increased MMP12 and Muc5ac, respectively. ENDS exposure to mice significantly increased the numbers of macrophages, particularly in M2 macrophages in bronchoalveolar lavage (BAL) fluid, despite ENDS did not induce M2 macrophage polarization in a cultured murine macrophage cell line (RAW264.7). There were no changes in neutrophils in BAL fluid by ENDS exposure. Multiple cytokine productions were increased including M-CSF, IL-1rα, IL-10, and TGF-β1, in BAL fluid from mice when exposed to ENDS. The Sirius Red staining and hydroxyproline assay showed ENDS-exposed mice displayed enhanced fibrotic phenotypes compared to control mice. In conclusion, ENDS exposure enhances airspace enlargement, mucus secretion, and fibrogenesis in COPD mice. This is associated with increased MMP12, inflammatory responses, and M2 macrophage phenotype. This study provides pre-clinical data implicating that electronic cigarette exposure is not safe in COPD patients who want to replace traditional cigarettes with ENDS.

JUUL the heartbreaker: Twitter analysis of cardiovascular health perceptions of vaping

INTRODUCTION

The public most frequently associates tobacco use solely with pulmonary health risks, despite heart disease being the leading cause of death in smokers. The health perceptions of e-cigarettes, especially cardiovascular health, have not been well studied. We aimed to evaluate the prevalence and health perceptions of tweets related to cardiovascular, pulmonary, and brain health – three organ systems for which tobacco use is a major disease risk factor.

METHODS

We examined the cardiovascular, pulmonary, and brain health perceptions of vaping and JUUL on Twitter, followed by a content analysis of tweets pertaining to the cardiovascular risks. A Twitter firehose API scraped about 6.2 million publicly available tweets from 2015–2019 that contained vaping-related terms, and a separate dataset of about 1.9 million tweets that contained the term JUUL. A quantitative content analysis (n=2145) of tweets was subsequently conducted to assess the health perceptions of vaping and JUUL. Two trained coders independently assessed the posts and Twitter profiles to determine age (<18 or ≥18 years), sex, race, sentiment towards JUUL, and vaping-related topics.

RESULTS

The majority of tweets containing vaping or JUUL-related terms did not also contain cardiovascular, pulmonary, or brain health terms (97.99% and 96.67%, respectively). Multiple linear regression analysis showed that youth (<18 years), females, non-White individuals, mention of a flavor, and mention of cardiovascular health harm words were associated with more positive sentiments towards JUUL. Pearson’s chi-squared analyses indicated that youth were more likely to mention a JUUL flavor. Females and youth were more likely to reference cardiovascular terms with humor.

CONCLUSIONS

The cardiovascular health risks of vaping are not fully recognized by the public. Vulnerable populations such as youth and females reference JUUL with cardiovascular-related words that downplay the severity of tobacco as a major risk factor for cardiovascular disease.