E-Cigarettes Reexamined: Product Toxicity

Electronic cigarette use and heavy metal exposure: Evidence from the Korea National Health and Nutrition Examination Survey

PURPOSE

This study investigated the association between electronic cigarette (e-cigarette) use and serum concentrations of heavy metals (lead, mercury, and cadmium) in the Korean population, utilizing data from the Korea National Health and Nutrition Examination Survey (KNHANES), a nationally representative cross-sectional survey.

METHODS

Data from KNHANES 2013, 2016, and 2017 were analyzed. Participants were classified as e-cigarette users (individuals who had ever used e-cigarettes, including dual users who had also used conventional cigarettes), conventional smokers (individuals who had smoked at least 100 conventional cigarettes [5 packs], but not e-cigarettes, in their lifetime), and non-smokers (individuals who had never used e-cigarettes and either never smoked conventional cigarettes or smoked fewer than 100 cigarettes). Linear regression models were employed to evaluate the association between smoking status and heavy metal concentrations, adjusting for covariates including age, sex, income, education, and health behaviors. Subgroup analyses were performed based on sex, age, and obesity status.

RESULTS

E-cigarette users exhibited significantly higher serum concentrations of heavy metals than non-smokers. Lead levels were 10.0 % higher (exponentiated β = 1.100; p < 0.001), mercury levels were 13.7 % higher (β = 1.137; p < 0.001), and cadmium levels were 61.4 % higher (β = 1.614; p < 0.001). Conventional smokers demonstrated elevated levels of these metals compared to non-smokers, but generally lower levels than e-cigarette users. Subgroup analyses revealed stronger associations among younger participants, males, and individuals with obesity, particularly for cadmium.

CONCLUSIONS

Dual use of e-cigarettes and conventional cigarettes is associated with elevated exposure to heavy metals compared to exclusive smoking cigarettes. These findings highlight the need for targeted public health interventions and stricter regulatory standards to address the risks associated with e-cigarette use.

Vaping cessation interventions: a systematic review and meta-analysis

OBJECTIVE

Electronic nicotine delivery systems (ENDS), such as e-cigarettes, have surged in popularity. While long-term risks remain unclear, known dangers include nicotine addiction, E-cigarette or Vaping Use-Associated Lung Injury and potential extrapulmonary effects on the heart, immune system and neurodevelopment. Addressing ENDS addiction may require strategies akin to smoking cessation. However, evidence is lacking; there are no currently approved vaping-cessation aids. The objective of this review is to summarise the available literature addressing interventions for vaping cessation.

DATA SOURCES AND STUDY SELECTION

A librarian-assisted search was conducted in MEDLINE, Embase and Scopus, as well as preprints in Europe PMC, Open Science Framework, and the grey literature searches until January 2024. Six included studies used self-report methods to determine the abstinence rate, while one study used cotinine-level-verified self-reported abstinence. We included randomised controlled trials (RCTs) that examine 'rates of vaping cessation' outcomes. An intention-to-treat approach was used for data extraction, and random-effects meta-analyses models were applied.

DATA SYNTHESIS

Seven RCTs were included, which studied pharmacological therapy, digital interventions and/or educational content. The primary meta-analyses demonstrated a statistically significant increase in the odds of achieving 7-day point prevalence abstinence (PPA) (OR 1.52, 95% CI 1.15 to 2.01, number of participants=3244, moderate-certainty) and continuous abstinence (OR 2.71, 95% CI 1.31 to 5.61, number of participants=164, low-certainty) following intervention. A non-significant increase in odds was noted at 30-day PPA (OR 1.32, 95% CI 0.72 to 2.42, number of participants=1994, very low certainty).

CONCLUSIONS

Vaping cessation interventions increase 7-day PPA rates at 1-12 months follow-up and this was consistent across prespecified subgroup analyses of the intervention type, outcome and duration of follow-up. More high-quality studies with reproducible findings are needed to enhance the certainty of the evidence and guide clinical interventions.

PROSPERO REGISTRATION NUMBER

CRD42022383670.

Urine proteomic analysis of the rat e-cigarette model

Background

We were curious if the urinary proteome could reflect the effects of e-cigarettes on the organism.

Methods

Urine samples were collected from a rat e-cigarette model before, during, and after two weeks of e-cigarette smoking. Urine proteomes before and after smoking of each rat were compared individually, while the control group was set up to rule out differences caused by rat growth and development.

Results

Fetuin-B, a biomarker of chronic obstructive pulmonary disease (COPD), and annexin A2, which is recognized as a multiple tumour marker, were identified as differential proteins in five out of six smoking rats on day 3. To our surprise, odourant-binding proteins expressed in the olfactory epithelium were also found and were significantly upregulated. Pathways enriched by the differential proteins include the apelin signalling pathway, folate biosynthesis pathway, arachidonic acid metabolism, chemical carcinogenesis-DNA adducts and chemical carcinogenesis-reactive oxygen species. They have been reported to be associated with immune system, cardiovascular system, respiratory system, etc.

Conclusions

Urinary proteome could reflect the effects of e-cigarettes in rats.

Vaping-Cessation Interventions in Former Smokers

This review provides an overview of potential vaping-cessation interventions in adult former smokers. The interventions reviewed include varenicline, bupropion, nicotine-replacement therapies (NRTs), and behavioural therapy. Evidence for intervention effectiveness is provided when available, such as for varenicline, whereas recommendations for bupropion and NRT are extrapolated from case studies or smoking-cessation guidelines. The limitations of these interventions, a general lack of prospective studies, and a discussion of challenges to vaping safety from a public health perspective are also discussed. Although these interventions show promise, further research is needed to establish precise protocols and dosages in the context of vaping cessation, rather than adapting existing recommendations from smoking cessation.

[Electronic cigarettes: harm reduction or harm prolongation?]

This paper deals with the question of whether electronic cigarettes (e-cigarettes) can minimize the proven harm of smoking tobacco or may lead to a long-term harm. While the British Royal College of Physicians recommends smokers to use e-cigarettes as a substitute for tobacco products, the German Society for Pneumology and Respiratory Medicine advises smokers against using e-cigarettes. The harm reduction strategy is based on three hypotheses. Hypothesis 1: It is assumed that e-cigarettes cause less damage to health than tobacco cigarettes. Hypothesis 2: It is postulated that smokers are motivated to switch from conventional cigarettes to e-cigarettes. Hypothesis 3: It is assumed that e-cigarettes are an effective means for quitting smoking with few side effects. Although the long-term health consequences of e-cigarette use remain unknown, there is increasing evidence that e-cigarettes are toxic, harmful to cardiovascular system, respiratory health and potentially carcinogenic. Population-representative epidemiological surveys have shown that three-quarters of all current e-cigarette users in Germany smoke tobacco at the same time. In a few randomized clinical trials, e-cigarettes showed higher success rates compared to nicotine replacement products. As over-the-counter consumer products, a large number of studies have found no advantage for e-cigarettes under real conditions. In addition, e-cigarettes prolong nicotine dependence compared to nicotine replacement products. According to the current state of knowledge, the hypotheses behind the harm minimization strategy using e-cigarettes must be regarded as refuted. It therefore appears ethically problematic when doctors recommend e-cigarettes to their patients as a substitute for smoking.