Systemic biomarkers of exposure associated with ENDS use: a scoping review

Changes in exposure to tobacco-related harmful and potentially harmful constituents among adults who switched completely from smoking cigarettes to use of the JUUL2 system for six days

INTRODUCTION

Adults who switch from smoking cigarettes to use of electronic nicotine delivery systems (ENDS) may reduce their exposure to harmful and potentially harmful constituents (HPHCs). This study assessed changes in exposure to HPHCs, assessed via biomarkers of exposure (BOEs), among adults who switched to a new ENDS product.

METHODS

Adults who smoke cigarettes (N = 89) were randomized to: (1) switch completely to using JUUL2 Virginia Tobacco (N = 24) or Polar Menthol (N = 24); (2) continue smoking usual brand (UB) cigarettes (N = 21); or (3) abstain from all tobacco/nicotine products (N = 20) for 6 d. Changes in exposure to nicotine and 11 other HPHCs from Baseline to Day 6 were compared among study groups.

RESULTS

Changes in nicotine exposure did not significantly differ between JUUL2 and UB Cigarette groups (ps > 0.37). Among participants who switched completely to JUUL2 products, median percent reductions (Day 6-Baseline) in non-nicotine BOEs ranged from 65% to 94%, significantly greater than changes in the UB Cigarette group (ps < 0.001). None of the non-nicotine BOEs significantly differed between the JUUL2 groups and the Abstinence group (ps > 0.025).

CONCLUSIONS

This randomized study demonstrates that adults who switch completely from smoking cigarettes to use of JUUL2 ENDS products substantially reduce their exposure to HPHCs associated with smoking-related diseases.

INTERNATIONAL STANDARD REGISTERED CLINICAL TRIAL NUMBER

ISRCTN27662176.

Optimising messages and images for e-cigarette warnings

BACKGROUND

The US Food and Drug Administration (FDA) requires electronic cigarettes (e-cigarettes) to have a single addiction warning, but many other health harms are associated with vaping and warnings grow stale over time. We aimed to develop new warning messages and images to discourage e-cigarette use.

METHODS

Participants were 1629 US adults who vaped or smoked. We randomised each participant to evaluate 7 of 28 messages on newly developed warning themes (metals exposure, DNA mutation, cardiovascular problems, chemical exposure, lung damage, impaired immunity, addiction), and the current FDA-required warning (total of 8 messages). Then, participants evaluated images of hazards (eg, metal), internal harms (eg, organ damage) or people experiencing harms.

RESULTS

Regarding intended effects, new warning themes all discouraged vaping more than the current FDA-required warning (all p<0.001), led to greater negative affect (all p<0.001) and led to more anticipated social interactions (all p<0.001). The most discouraging warnings were about toxic metals exposure. Regarding unintended effects, the new themes led to more stigma against people who vape (6 of 7 themes, p<0.001) and led to a greater likelihood of thinking vaping is more harmful than smoking (all 7 themes, p<0.001), although unintended effects were smaller than intended effects. Images of harms (internal or people experiencing) discouraged vaping more than images of hazards (all p<0.001).

DISCUSSION

Vaping warning policies should communicate a broader range of hazards and harms, beyond addiction, to potentially increase awareness of health harms. Images of internal harm or people experiencing harms may be particularly effective at discouraging vaping.

Kowitt S, Ritchie C, Sutfin EL, Sheeran P, Noar SM. Awareness and Perceptions of US Food and Drug Administration's JUUL Marketing Denial Order: A National Study of US Adolescents

INTRODUCTION

We examined awareness and perceptions of the US Food and Drug Administration (FDA) JUUL marketing denial order (MDO) that occurred in June 2022 among a nationally representative sample of US adolescents.

AIMS AND METHODS

Data were collected in August 2022 via an online survey (n = 1603). Adolescents were asked whether they had heard about the JUUL MDO, and, if yes, where they heard the news. Those who had heard were asked about the MDO's impact on their harm beliefs about JUUL and vape products in general. We examined correlates of awareness of the MDO and of increased JUUL and vape harm perceptions.

RESULTS

Twenty-seven percent of adolescents had heard about the MDO. Older adolescents (adjusted odds ratio [aOR] = 1.13) and LGBTQ+ adolescents (aOR = 2.05) had significantly higher odds of having heard the news, while those who identified as Black or African American had significantly lower odds of having heard (aOR = 0.56). Most participants who were aware of the MDO indicated that they had higher harm perceptions about JUUL itself (77.9%) and vapes in general (79.6%). Youths susceptible to vaping and current users were less likely to report increased harm perceptions about JUUL (B = -0.34 and -0.46, respectively) and vapes in general (B = -0.27 and -0.43) compared with youth not susceptible to vaping.

CONCLUSIONS

The results of this nationally representative survey demonstrate that over one-quarter of US youth heard about the JUUL MDO and the vast majority of those indicated increased harm perceptions about vapes. Large-scale news events about vaping can reach youth audiences and may impact what youth think about the harms of vaping.

IMPLICATIONS

Analysis of a nationally representative survey of adolescents aged 13-17 revealed that more than 25% had heard about the marketing denial order issued to JUUL Labs by the FDA in June of 2022. We also found that the vast majority of adolescents reported increased JUUL and vape harm perceptions in response to hearing about the MDO. This indicates that news coverage about vaping-including coverage of regulatory actions-can reach and potentially impact adolescents. It is therefore important to monitor news coverage about vaping, how it is framed and discussed across media platforms, and its reach among priority populations.

Comparing Adult Smokers Who Switched to JUUL versus Continuing Smokers: Biomarkers of Exposure and of Potential Harm and Respiratory Symptoms

OBJECTIVES

Real-world evidence on exposure to harmful and potentially harmful constituents (HPHCs) and on biological effects in cigarette smokers who switch to electronic nicotine delivery systems (ENDS) can inform the health effects of switching.

AIMS AND METHODS

This cross-sectional, observational study assessed adults who had smoked ≥10 cigarettes/day for ≥10 years, comparing 124 continuing cigarette smokers (Smokers) to 140 former smokers who switched to JUUL-brand ENDS exclusively for ≥6 months (Switchers). Assessments included biomarkers of exposure (BOEs) to select HPHCs, biomarkers of potential harm (BOPHs) related to smoking-related diseases, psychometric assessments of dependence on cigarettes and ENDS, respectively, and respiratory symptoms. Planned analyses compared geometric means, adjusted for demographic covariates; further analyses adjusted for additional lifestyle and smoking history covariates.

RESULTS

Nicotine levels were significantly higher in Switchers (median time switched = 3 years), who were unusually heavy users of JUUL. All other BOEs, including NNAL and HPMA3 (primary endpoints), were significantly lower in Switchers than Smokers. Most BOPHs (sICAM-1 [primary], and eg, white blood cell count, MCP1, HbA1c) were significantly lower in Switchers than Smokers; HDL was significantly higher. Switchers reported significantly lower dependence on JUUL than Smokers did on cigarettes, and respiratory symptom scores were significantly lower among Switchers than Smokers.

CONCLUSIONS

Compared to continuing smokers, smokers who switched to JUUL had substantially lower exposures to multiple HPHCs, favorable differences in markers of inflammation, endothelial function, oxidative stress, and cardiovascular risk, and fewer respiratory symptoms. These findings suggest that switching from cigarettes to JUUL likely reduces smokers' health risks.

IMPLICATIONS

Short-term confinement studies and randomized clinical trials demonstrate that adult smokers who switch completely to ENDS experience substantial reductions in exposure to many smoking-related toxicants. This study extends those findings to longer periods of switching to JUUL-brand ENDS (almost 3 years on average) under naturalistic use conditions in real-world settings and also found that switching to JUUL resulted in favorable differences in BOPHs more proximally related to smoking-induced disease, as well as in respiratory symptoms. Smokers who switch to ENDS reduce their exposure to toxicants, likely reducing their disease risk.

Electronic Cigarette Harms: Aggregate Evidence Shows Damage to Biological Systems

Evidence of the harms of e-cigarettes has been unfolding slowly and has been documented in many reviews and reports worldwide. A narrative review of new evidence is presented since, as research has continued, newly aggregated evidence of the dangers of electronic cigarettes on the brain, heart, and lungs is vital to inform decisions on restricting the use of e-cigarettes. Several biomedical research databases were searched for electronic cigarette health effects, emphasizing reviews, systematic reviews, and meta-analyses. Over 50 review studies, primarily in 2022 and 2023, illustrate some of the latest information on e-cigarette harms. Results show studies of respiratory, neurological, and cardiovascular effects. Researchers call for expanding studies through new methods to elaborate on initial findings of multiple harms emerging in clinical investigations. Since the use of electronic cigarettes for adult cessation is not sanctioned in most countries, it is clear that health authorities see significant costs to the health of the general population if the promotion and use of electronic cigarettes occur worldwide. Regulatory action to control electronic cigarettes should consider the substantial evidence of electronic cigarette harm.

Comparison of biomarkers of exposure among US adult smokers, users of electronic nicotine delivery systems, dual users and nonusers, 2018-2019

The harm caused by cigarette smoking is overwhelmingly due to byproducts of tobacco combustion. Electronic Nicotine Delivery Systems (ENDS) provide nicotine to users without combustion, and may support tobacco harm reduction among cigarette smokers who would not otherwise quit in the near term. Analyses of Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study compared biomarkers of exposure (BOE) levels for nicotine, 3 metals, 2 tobacco-specific nitrosamines and 14 smoking-related volatile organic compounds in 151 exclusive ENDS users, 1341 exclusive cigarette smokers, 115 dual users (cigarettes and ENDS), and 1846 past 30-day nonusers of tobacco, adjusting for demographics. Nicotine exposure in ENDS users and dual users did not significantly differ from smokers. Among ENDS users, 16 of 18 other BOEs were significantly lower than smokers'; 9 BOEs were not significantly different from nonusers. Among dual users smoking < 10 cigarettes/day, 15 of 18 non-nicotine BOEs were significantly lower than smokers', whereas in dual users smoking ≥ 10 cigarettes per day none of the BOEs significantly differed from smokers'. In this representative sample of US adults, exclusive use of ENDS (vs. cigarette smoking) was associated with much lower exposures to many harmful chemicals associated with smoking-related disease. BOE levels in dual users were directly related to their cigarette consumption. These BOE data provide further evidence that ENDS expose users to substantially lower levels of toxicants than combustible cigarettes, confirming their potential for harm reduction.

IMPACT OF E-CIGARETTES ON THE ORAL HEALTH - LITERATURE REVIEW

E-cigarettes are electronic devices used to inhale aerosols generated from the vaporization of flavored liquids. Nowadays, the use of e-cigarettes has become one of the most popular alternatives to traditional smoking. The wide variety of devices and liquids makes it challenging to assess the health effects of using e-cigarettes. During the vaporization of e-liquids, toxins, carcinogens, and various other chemicals can be released and inhaled by the user. Limited data exist regarding the potential health impact of exposure to e-vapors, primarily derived from animal studies and in vitro research. The oral tissues are the first site of direct interaction with the components of the inhaled vapor. While e-cigarettes are commonly portrayed as safer alternatives to tobacco cigarettes, little is known about the short- or long-term health effects of their use. The aim of this review is to briefly present the available data regarding the impact of chemical ingredients and toxins present in e-cigarette vapors on oral cavity cells.

Increased Levels of the Acrolein Metabolite 3-Hydroxypropyl Mercapturic Acid in the Urine of e-Cigarette Users

Carcinogen and toxicant uptake by e-cigarette users have not been fully evaluated. In the study reported here, we recruited 30 e-cigarette users, 63 nonsmokers, and 33 cigarette smokers who gave monthly urine samples over a period of 4-6 months. Their product use status was confirmed by measurements of exhaled CO, urinary total nicotine equivalents, cyanoethyl mercapturic acid (CEMA), and total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol. Urinary biomarkers of exposure to the carcinogens acrolein (3-hydroxypropyl mercapturic acid, 3-HPMA), benzene (S-phenyl mercapturic acid, SPMA), acrylonitrile (CEMA), and a combination of crotonaldehyde, methyl vinyl ketone, and methacrolein (3-hydroxy-1-methylpropyl mercapturic acid, HMPMA) were quantified at each visit. Data from subject visits with CEMA > 27 pmol/mL were excluded from the statistical analysis of the results because of possible unreported exposures to volatile combustion products such as secondhand cigarette smoke or marijuana smoke exposure; this left 22 e-cigarette users with 4 or more monthly visits and all 63 nonsmokers. Geometric mean levels of 3-HPMA (1249 versus 679.3 pmol/mL urine) were significantly higher (P = 0.003) in e-cigarette users than in nonsmokers, whereas levels of SPMA, CEMA, and HMPMA did not differ between these two groups. All analytes were significantly higher in cigarette smokers than in either e-cigarette users or nonsmokers. The results of this unique multimonth longitudinal study demonstrate consistent significantly higher uptake of the carcinogen acrolein in e-cigarette users versus nonsmokers, presenting a warning signal regarding e-cigarette use.

Increased acrolein-DNA adducts in buccal brushings of e-cigarette users

DNA adducts are central in the mechanism of carcinogenesis by genotoxic agents. We compared levels of a DNA adduct of acrolein, a genotoxic carcinogen found in e-cigarette vapor, in oral cell DNA of e-cigarette users and non-users of any tobacco or nicotine product. e-Cigarette users and non-users visited our clinic once monthly for 6 months, and oral brushings and urine samples were collected. For this study, we analyzed oral cell DNA adducts from three monthly visits in e-cigarette users and non-users as confirmed by urinary cyanoethyl mercapturic acid and total nicotine equivalents. DNA was isolated from the oral brushings and analyzed by a validated liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry method for the acrolein DNA adduct 8R/S-3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a]purine-10-(3H)-one (γ-OH-Acr-dGuo). The median value of this DNA adduct in the e-cigarette users was 179 fmol/µmol dGuo (range 5.0 - 793 fmol/µmol dGuo) while that for non-users was 21.0 fmol/µmol dGuo (range 5.0 - 539 fmol/µmol dGuo), P = 0.001. These results demonstrate for the first time that e-cigarette users have elevated levels of a carcinogen-DNA adduct in their oral cells.