An 8-year longitudinal study of long-term, continuous users of electronic cigarettes

BACKGROUND AND AIMS

E-cigarettes have been available for over 15 years, but relatively little is known about long-term users. Our aim was to describe change over time in behaviours, attitudes and dependence in long-term users.

DESIGN AND PARTICIPANTS

A longitudinal study of 375 e-cigarette users enrolled on the Internet in 2012-2016 and surveyed again in 2021 (8 years later on average), who continuously used e-cigarettes in the interval.

FINDINGS

Fewer people in 2021 (11 %) than at baseline (33 %) had smoked tobacco in the past 31 days. Participants switched from second-generation models at baseline (e.g. Ego) to box mods in 2021 (e.g. iStick), they used larger refill bottles, they used home-made e-liquids twice as often, they used tobacco flavours less often and the nicotine concentration in e-liquids decreased from 12 to 6 mg/mL. There was no change over time in the time to the first e-cigarette puff of the day, but an e-cigarette dependence score of 0-100 decreased from 75 to 60, the frequency and strength of urges to vape decreased (from 31 % to 18 % of "strong" urges) and the proportion of people who said they would be likely to succeed if they tried to stop vaping increased. Compared to baseline, fewer people in 2021 reported vaping to cope with cravings or other smoking cessation symptoms, and fewer people reported vaping to quit smoking, to avoid relapse into smoking, or to reduce their tobacco consumption (p < 0.001 for all differences).

CONCLUSIONS

In long-term, continuous users, over a period of 8 years, substantial changes were observed in the models of e-cigarettes used, in the flavours and strength of e-liquids, and in the reasons for vaping. Their level of nicotine dependence tended to decrease over time. These users were satisfied with e-cigarettes and vaped mostly because they felt that vaping was less dangerous than smoking, and for enjoyment.

Comparison of a Tobacco-Specific Carcinogen in Tobacco Cigarette, Electronic Cigarette, and Dual Users

BACKGROUND

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is known as a lung carcinogen. The objective of this study was to investigate associations of urine NNAL concentrations and smoking status.

METHODS

This was a cross-sectionally designed study based on data from the 2016-2018 Korean National Health and Nutrition Examination Survey. A total of 2,845 participants were classified into past-smoker, electronic cigarette (e-cigar) only, dual-user, and cigarette only smoker groups. All sampling and weight variables were stratified and analysis was conducted accounting for the complex sampling design. Analysis of covariance was used to compare the geometric mean of urine NNAL concentrations and log-transformed urine NNAL level among smoking status with weighted survey design. Post hoc paired comparisons with Bonferroni adjustment was performed according to smoking status.

RESULTS

The estimated geometric mean concentrations of urine NNAL were 1.974 ± 0.091, 14.349 ± 5.218, 89.002 ± 11.444, and 117.597 ± 5.459 pg/mL in past-smoker, e-cigar only, dual-user, and cigarette only smoker groups, respectively. After fully adjusting, log-transformed urine NNAL level was significantly different among groups (P < 0.001). Compared with the past-smoker group, e-cigar only, dual-user, and cigarette only smoker groups showed significantly higher log-transformed urine NNAL concentrations in post hoc test (all P < 0.05).

CONCLUSION

E-cigar only, dual-user, and cigarette only smoker groups showed significantly higher geometric mean concentrations of urine NNAL than the past-smoker group. Conventional cigarette, dual users, and e-cigar users can potentially show harmful health effects from NNAL.

Electronic Cigarette or Vaping-Associated Lung Injury Manifested as Acute Eosinophilic Pneumonia: A Case Report

Electronic cigarette or vaping-associated lung injury (EVALI) is a disease defined by lung injuries caused by e-cigarette use. It predominantly manifests in forms of organized pneumonia or diffuse alveolar damage but rarely as acute eosinophilic pneumonia (AEP). This report describes a 34-year-old male with acute respiratory symptoms and a vaping history of only nicotine. Chest CT revealed peripheral distributing multiple patchy consolidations and ground-glass opacities dominant in both lower lobes, bilateral diffuse interlobular septal thickening, and bilateral pleural effusion without cardiomegaly. Bronchoalveolar lavage fluids showed increased eosinophilia levels, while infectious laboratory results were all negative, enabling the diagnosis of both AEP and EVALI. Herein, we report a rare case of only-nicotine vaping EVALI manifested as AEP.

Human Bronchial Epithelial Cell Culture Models for Cigarette Smoke and Vaping Studies

Despite the continuing public health efforts to stop or reduce smoking, cigarette smoke use remains popular in the youth and adult population. A recent surge in the use of electronic cigarette and vaping products has created another major health challenge in public health. There is an urgent need to use physiologically relevant models to study the health effect of smoking or vaping in human subjects. Airway diseases such as bronchitis (Landman et al., CMAJ 191:E1321-E1331, 2019; Goniewicz, et al. Harm Reduct J 17:91, 2020; Xie et al., JAMA Netw Open 3:e2020816, 2020) have been described in people who smoke, vape, or both. Here, we will describe methods to collect, expand, and culture human airway epithelial cells from endobronchial brushings and expose these cells cultured at the air-liquid interface to cigarette smoke or electronic cigarette vapor.

E-Cigarettes: A New Threat to Cardiovascular Health - A World Heart Federation Policy Brief

Tobacco is widely recognized as a leading cause of cardiovascular morbidity and mortality, accounting for approximately seventeen percent of all cardiovascular disease deaths globally. Electronic nicotine delivery systems such as e-cigarettes have been developed and advertised as safer alternatives to traditional tobacco cigarettes. Aggressive marketing strategies, as well as misleading claims by manufacturers, have largely contributed to the belief that e-cigarettes are harmless.

In reality, e-cigarettes are far from innocuous. E-cigarette solutions and aerosols generally contain harmful substances that are commonly found in tobacco cigarette emissions. A growing body of literature suggests that e-cigarettes are associated with an increased risk of cardiovascular morbidity and mortality. In addition, the effectiveness of e-cigarettes as smoking cessation tools has yet to be determined. Concerningly, most smokers do not give up on tobacco cigarettes and eventually become dual users.

Unregulated, e-cigarettes constitute a serious threat to established tobacco control policies. Fortunately, many countries have demonstrated that strong regulations were effective in protecting their populations from the dangers of e-cigarettes. The World Heart Federation recommends applying the precautionary principle and a set of measures to protect vulnerable populations, prevent exposure to second-hand smoking, and address misleading claims.

In this regard, we recommend that governments, policymakers, and other relevant stakeholders enact or support the following measures, among others:

Prohibit the sale and distribution of e-cigarettes to minors, as well as the use of flavouring agents.

Prohibit the use of e-cigarettes anywhere tobacco cigarettes have been banned.

Prohibit marketing, advertising, and misleading claims regarding e-cigarettes.

Apply excise taxes on e-cigarettes.

Conduct more research regarding the long-term effects of e-cigarettes on cardiovascular health.

Lastly, countries that have banned the commercialization of e-cigarettes should maintain these measures.

Assessing adolescent tobacco use in a substance use treatment program with self-report and biological measures

Tobacco use in adolescents can alter their lifetime health outcomes. Despite the importance of early identification and treatment, adolescent tobacco use, including that of electronic vapor products (e.g., e-cigarettes), is often missed. In a state-funded substance use treatment program, we added biological measures, including urinary cotinine and exhaled carbon monoxide to self-report measures to assess recent and lifetime tobacco use. We conducted a retrospective review of the de-identified charts to examine the feasibility of screening for self-report and biological measures of tobacco use. Self-report, urinary cotinine, and exhaled carbon monoxide samples were obtained at every visit, including intake and follow-up. There were 52 adolescents with a total of 400 clinic visits to the program. Of those 400 visits, 258 included self-reported tobacco use and 142 included a denial of using any form of tobacco. However, of those 142 visits with a negative self-report of tobacco, 31 tested positive for cotinine and 6 had positive exhaled carbon monoxide. Although 111 of the 142 had negative cotinine, 5 had positive carbon monoxide, but all of those self-reported recent cannabis use. Despite using a sensitive measure of self-report of tobacco use, almost 22% of visits had a discordant self-report with a biological measure that indicated tobacco use. Considering the lifelong impact of adolescent tobacco use, clinicians should consider augmenting self-report with biological measures of tobacco use. Identification of tobacco use in adolescents with substance use can assist clinicians in providing education about tobacco use, such as electronic vapor products, and individualizing treatments.

Cigarette Smoking in Men and Women and Electronic Cigarette Smoking in Men are Associated with Higher Risk of Elevated Cadmium Level in the Blood

BACKGROUND

We investigated the association between blood concentration of cadmium and smoking status including use of electronic cigarettes (E-cigars).

METHODS

We used data from the Korea National Health and Nutritional Survey 2013 and 2016. A total of 4,744 participants (2,162 men and 2,582 women) were included and were categorized into five groups (Non-smokers, E-cigar non-users in past-smokers, E-cigar users in past-smokers, E-cigar non-users in cigarette-smokers and E-cigar users in cigarette-smokers). Cadmium blood concentration was categorized into tertiles. All sampling and weight variables were stratified, and analysis to account for the complex sampling design was conducted.

RESULTS

In both genders, the geometric cadmium concentration was significantly different according to smoking status (both genders, analysis of variance P value < 0.001). In men, E-cigar users were significantly higher than the non-smokers (P value = past-smokers, 0.017; cigarette-smokers, < 0.001) when fully adjusted. Compared with non-smokers, fully-adjusted odds ratios (95% confidence intervals) for the highest cadmium tertiles of E-cigar non-users in cigarette-smokers and E-cigar users in cigarette-smokers were 6.56 (3.55-12.11) and 5.68 (1.96-16.50) in men and 2.74 (1.42-5.29) and 1.29 (0.10-17.44) in women.

CONCLUSION

Conventional cigarette smoking in men and women and E-cigar use in men are associated with higher risk of elevated blood cadmium level. Preventive management of cadmium exposure monitoring in conventional cigarette-smokers and E-cigar users may be needed.

When Visual Cues Activate Moral Foundations: Unintended Effects of Visual Portrayals of Vaping within Electronic Cigarette Video Advertisements

Within multimodal persuasive messages, the roles of visual cues in producing unintended effects have been understudied. In an experiment on a sample of former and current smokers (N = 991), we manipulated the presence of visual vaping cues within electronic cigarette video advertisements (N = 25) to evaluate opinions towards vape-free policies. Such cues diminished the effects of pro-vaping arguments to increase support for vape-free policies, inadvertently benefiting public health. Consistent with the moral foundations theory (MFT), endorsement of the care/harm moral foundation strengthened message effects. Furthermore, cognitions and emotions related to moral intuitions mediated the effects of visual vaping cues. These findings suggest that MFT can help explain unintended effects of visual cues when outcomes are related to morality.

The Emerging Method of Suicide by Electronic Cigarette Liquid: a Case Report

Electronic cigarettes (ECs) are a device that aerosolize liquid nicotine by heating a solution of nicotine, glycerol and flavoring agents. The awareness and the usage of ECs has increased in many countries. Due to the online sales and the absence of EC regulations, the prevalence of EC usage is especially high in adolescents and young adults. Due to the large amount and the high nicotine concentration of EC liquid, the ingestion for suicide can lead to cardiac death. We had two patients, a 27-year-old male who ingested about 23 mg/kg of nicotine and a 17-year-old female who ingested about 30 mg/kg of nicotine. Both patients presented seizure-like movement and cardiac arrest. They had metabolic acidosis and transient cardiomyopathy. They were ultimately discharged with a cerebral performance category of 2 and 4, respectively. Increasing EC use may produce more cases of medical problems or suicide by nicotine intoxication.

Ideology versus evidence: Investigating the claim that the literature on e-cigarettes is undermined by material conflict of interest

A review of the health effects of e-cigarettes (EC) by Pisinger and Dossing concluded that any reassuring the evidence on the contents of e-cigarettes cannot be trusted because 'A substantial number of studies were funded or otherwise supported by manufacturers of ECs' and the relevant literature is influenced by 'severe conflicts of interest' (A). The review also asserts that 'Conflict of interest seems to influence the conclusions of these papers' (BC). These claims have been embraced and magnified by EC opponents. The Pisinger and Dossing review included 76 studies and considered 26 (34%) to be 'funded or otherwise supported' by the industry. As the review identifies the 'conflicted' studies, such a claim can be checked. In summary, only 10 (13%) of articles covered by the review were sponsored by the industry and only 5 are published studies. Claim 'A' is misleading. Regarding claim 'B', it appears to have been conceived independent of any empirical support. Recently, anti-EC activists and media started to use conflict of interest accusations to disparage the validity of empirical evidence showing that vaping is much safer than smoking. Evidence needs to be considered on its merits rather than from the perspective of preconceived ideological positions.

Has the mist been peered through? Revisiting the building blocks of human health risk assessment for electronic cigarette use

Background

Electronic cigarettes, battery-powered nicotine delivery devices, have been increasingly used in the past decade. However, human health risks associated with E-vapor inhalation have not been fully characterized.

Aims

This critical review aims at revisiting the building blocks of human health risk assessment, summarizing the state of the science, and identifying major knowledge gaps in exposure assessment and toxicity assessment.

Approach

A qualitative research synthesis was conducted based on scientific findings reported to date in peer-reviewed publications and our own preliminary experimental results.

Results

There are a limited number of studies across all lines of evidence on E-vapor exposure and the health impacts of E-vapor inhalation. E-cigarette may be as efficient as traditional cigarettes in nicotine delivery, especially for experienced users, and studies suggest lower emissions of air toxics from E-cigarette vapor and lower second- and third-hand vapor exposures. But some toxic emissions may surpass those of traditional cigarettes, especially under high voltage vaping conditions. Experimentally, E-vapor/E-liquid exposures reduce cell viability and promote pro-inflammatory cytokine release. User vulnerability to concomitant environmental agent exposures, such as viruses and bacteria, may potentially be increased.

Conclusion

While evidence to date suggests that e-cigarettes release fewer toxins and carcinogens and compared to cigarettes, E-vapor is not safe and might adversely affect human immune functions. Major knowledge gaps hinder risk quantification and effective regulation of E-cigarette products including: 1) lack of long-term exposure studies; 2) lack of understanding of biological mechanisms associated with exposure; and 3) lack of integration of exposure and toxicity assessments.,. Better data are needed to inform human health risk assessments and to better understand the public health impact of E-vapor exposures.