IQOS: examination of Philip Morris International's claim of reduced exposure

Patterns of use of heated tobacco products: a comprehensive systematic review

INTRODUCTION

Relative or absolute safety of heated tobacco products (HTP) remains unknown, while independent literature suggests that these products do not favour tobacco control. We conducted a comprehensive systematic review and meta-analysis to evaluate HTP usage patterns and the effect of HTP use on conventional tobacco smoking (use transitions).

METHODS

We used Pubmed/MEDLINE, Embase and the Cochrane Library to identify all articles published up to February 2022 on HTP use. For the present review, we included all representative cross-sectional studies dealing with HTP use, and all prospective cohort studies or cross-sectional studies on conventional tobacco smoking transitions due to HTP use. From 610 non-duplicate articles, 76 were eligible (71 cross-sectional and 5 prospective cohort studies).

RESULTS

Compared with young adults, HTP use was less frequent among middle-aged (pooled odds ratio, OR=0.59; 95% confidence interval, CI: 0.48-0.74; number of studies, n=15) and older adults (OR=0.17; 95%-CI: 0.07-0.38; n=12). HTP use was more frequent among former (OR=2.73; 95%-CI: 1.03-7.25; n=6) and current smokers (OR=14.53; 95%-CI: 6.34-33.31; n=12). Overall, 68.3% of HTP users were dual users (n=26). Eight studies (including 5 cohorts) showed that HTP users were more likely than non-users to start conventional cigarette smoking (OR=6.31; 95%-CI: 4.13-9.65; n=2), whereas current cigarette smokers using HTPs were less likely to quit (OR=0.84; 95%-CI: 0.80-0.89; n=4).

CONCLUSIONS

We found that HTPs are specifically popular among young generations. More than two out of three HTP users are dual users. Prospective studies consistently show that in real life HTPs are not effective smoking cessation tools.

Can switching from cigarettes to heated tobacco products reduce consequences of pulmonary infection?

RATIONALE

While tobacco industry data suggests that switching from combustible cigarettes to heated tobacco products (HTPs), like IQOS, may reduce the users' exposure to respiratory toxicants, it is not known if using HTPs impacts the outcomes of acute respiratory infections.

OBJECTIVES

Does switching from cigarettes to HTPs improve responses to pulmonary infection.

METHODS

We conducted experiments in which 3 groups of mice were pre-exposed to cigarette smoke for 8 weeks, followed by 8-week exposure to (1) HTPs (tobacco product switching), (2) air (smoking cessation), or (3) continued exposure to cigarette smoke. Pulmonary bacterial clearance and surrogate markers of lung damage were assessed as study outcomes.

MAIN RESULTS

Significantly compromised clearance of bacteria from the lungs post-acute challenge occurred in both the switching group and in mice continuously exposed to cigarette smoke. Bacterial clearance, inflammatory T-cell infiltration into the lungs, and albumin leak improved at 12 h post-acute challenge in the switching group compared to mice continuously exposed to cigarette smoke. Bacterial clearance, total lung immune-cell infiltration, inflammatory T-cell infiltration into the lungs, the content of total proteins in the BAL, and albumin leak measured post-acute challenge were compromised in the switching group compared to mice in the cessation group. Switching from cigarettes to HTPs did not improve lung myeloperoxidase and neutrophil elastase levels (markers for lung inflammation and damage), which, however, were significantly reduced in the cessation group.

CONCLUSIONS

This study reveals only a modest improvement in respiratory infection outcomes after switching exposure from cigarettes to HTPs and significantly compromised outcomes compared to a complete cessation of exposure to all tobacco products.

Impacts of revised smoke-free regulations under the 2020 Japan Health Promotion Act on cigarette smoking and heated tobacco product use in indoor public places and homes: findings from 2018 to 2021 International Tobacco Control (ITC) Japan Surveys

BACKGROUND

In April 2020, Japan's revised Health Promotion Act (HPA) banned cigarette smoking and heated tobacco products (HTP) use in indoor public places but exempted small establishments and permitted smoking-designated/HTP-designated rooms. This pre-post study evaluated the effectiveness of the HPA.

METHODS

Data were from waves 1 to 4 (2018-2021) of the International Tobacco Control Japan Surveys among a national cohort of adults who smoke cigarettes, use HTPs and do not use any tobacco products. The sample sizes in the respective surveys were 4615, 4222, 4387 and 4254. Multivariable logistic regression models employing generalised estimating equations estimated the prevalence of observed and self-reported indoor smoking/HTP use in key public venues (restaurants/cafés, bars/pubs and workplaces), smoke-free places, and homes, and smoke-free/HTP aerosol-free home policies (model 1). The models were additionally adjusted for waves 1-4 to estimate the impacts of the HPA (model 2).

RESULTS

The implementation of the HPA significantly reduced observed indoor smoking in bars/pubs (model 1: 82.2% (pre) to 55.5% (post), model 2: p=0.04) but not in restaurants/cafés (model 1: 53.0%-24.9%, model 2: p=0.15) or workplaces (model 1: 35.3%-30.1%, model 2: p=0.62). Observed indoor HTP use was also common postimplementation (restaurants/cafés: 19.6%, bars/pubs: 53.9%, workplaces: 36.4%). The implementation of the HPA was associated with a significant increase in observed HTP use in smoke-free places (model 1: 26.3%-33.3%, model 2: p=0.001) and a suggestive increase in homes without HTP aerosol-free policies among adults who smoke (model 1: 64.0%-77.0%, model 2: p=0.09).

CONCLUSIONS

The implementation of the HPA was limited in its effectiveness. Comprehensive regulations with no exemptions are needed in Japan.

Internal exposure to heat-induced food contaminants in omnivores, vegans and strict raw food eaters: biomarkers of exposure to 2- and 3-monochloropropanediol (urinary excretion) and glycidol (hemoglobin adduct N-2,3-dihydroxypropyl-Val)

Fatty acid esters of 2/3-monochloropropanediol (2/3-MCPD) and glycidol are formed mainly during heat processing (deodorization) of vegetable oils, and are hydrolyzed by lipases in the gastrointestinal tract leading to the absorption of 2/3-MCPD and glycidol. The International Agency for Research on Cancer (IARC) has classified 3-MCPD as possibly and glycidol as probably carcinogenic to humans. The aims of the current work were to clarify the exposure to 2/3-MCPD and glycidol associated with different dietary habits (omnivore, vegan, raw-food eating), and the exposure development between 2017 and 2021 in German study participants. The questions were addressed using the daily urinary excretion of 2/3-MCPD and the hemoglobin adduct N-(2,3-dihydroxypropyl)-Val (DHP-Val) formed from glycidol as biomarkers of exposure, which were determined in two dietary studies including 36 omnivores, 36 vegans and 16 strict raw food eaters (abstaining from any heated food for at least four months). The median urinary excretion of 2- and 3-MCPD in non-smoking omnivores and vegans was 0.87 and 1.35 µg/day (2-MCPD), respectively, and 0.79 and 1.03 µg/day (3-MCPD), respectively. The 2/3-MCPD concentrations in urine samples of raw food eaters were usually below the limit of detection. The median DHP-Val levels in non-smoking vegans and omnivores were 3.9 pmol/g Hb each, and 1.9 pmol/g Hb in raw food eaters. Between 2017 and 2021, the exposure to 3-MCPD and glycidol did not change, however, the median 2-MCPD excretion decreased (p = 0.02, omnivores and vegans combined). The correlation between daily excretions of 2/3-MCPD determined 4 years apart was weak, whereas a moderate correlation was observed for DHP-Val (rS = 0.66) in this timeframe. In conclusion, the exposure to glycidol in omnivores and vegans was alike, whereas the 2/3-MCPD exposure was somewhat (albeit not significantly) higher in vegans. While 2/3-MCPD were hardly detectable in urine samples of raw food eaters, the median DHP-Val level (about 50% of those in omnivores) indicates a glycidol source independent of the dietary exposure.

The Impact of Heat-Not-Burn, E-Cigarettes, and Cigarettes on Small Airway Function

Introduction

E-cigarettes and heated tobacco products (HTPs) are gaining worldwide significance. The tobacco industry is promoting these products as healthier alternatives to conventional cigarettes.

Methods

In this four-arm crossover study, we examined the acute effects of cigarette smoking, vaping IQOS, or vaping e-cigarettes (with or without nicotine) on hemodynamics, arterial stiffness, and small airways. Twenty subjects (10 male, 10 female), all occasional smokers, completed each study arm. There was at least a 48 h washout period before each test day. Arterial stiffness and peripheral and central hemodynamics were assessed using Mobil-O-Graph™ (I.E.M., Germany), whereas tremoFlo® c-100 (Thoracic Medical Systems Inc) was used to evaluate the effects on the small airways and resistance.

Results

Cigarettes, IQOS, e-cigarettes containing nicotine, and nicotine-free e-cigarettes had similar effects on peripheral and central hemodynamics as well as on arterial stiffness. We observed a significant increase in all parameters. However, only nicotine-containing products lead to increased bronchial obstruction, higher reactance, and a higher tidal volume.

Conclusion

Therefore, we concluded that cigarettes, IQOS, and e-cigarettes have similar effects on hemodynamics. No differences were observed between the nicotine-containing and nicotine-free e-cigarettes. All nicotine-containing products also influence small airways. These findings suggest that e-cigarettes and HTPs are not healthier alternatives than conventional cigarettes.

Health outcomes of electronic cigarettes

ABSTRACT

The usage of electronic cigarettes (e-cigarettes) sparked an outbreak of unidentified vaping-related lung disease in the US during late 2019. With e-cigarettes becoming more and more popular, smokers have more options other than conventional cigarettes. Under these circumstances, a comprehensive evaluation of the general safety of new tobacco and tobacco-related products, represented by e-cigarettes, to human health is necessary. In this review, we summarize the current research on potential negative impacts of e-cigarette exposure on human health. In particular, studies detailing the relationship between e-cigarettes and the digestive system are summarized, with mechanisms mainly including hepatic metabolic dysfunction, impaired gut barrier, and worsened outcomes of inflammatory bowel disease (IBD). Although believed to be safer than traditional cigarettes, e-cigarettes exert adverse effects on systemic health and induce the development of multiple diseases including asthma, cardiovascular disease, and IBD. Moreover, nicotine-containing e-cigarettes have a negative impact on the childhood development and increase the risk of arterial stiffness compared to the non-nicotine e-cigarettes. However, non-nicotine e-cigarette components have detrimental effects including promoting liver damage and metabolic disorders.

E-cigarette exposure disrupts antitumor immunity and promotes metastasis

Electronic cigarettes (e-cigarettes) are thought to pose low risk of cancer because the components of e-cigarette liquid are not carcinogens. We analyzed the effects of the two major components, PG/VG and nicotine, on tumor development in preclinical models. We found that PG/VG promoted tumor cell migration in migration assays and contributed to more aggressive, metastatic, and immunosuppressive tumors in vivo, aggravated by the presence of nicotine. Whole body exposure of mice to PG/VG and nicotine rendered animals more susceptible to developing tumors with high frequencies of infiltrating proinflammatory macrophages expressing IL-6 and TNFα. Moreover, tumor-infiltrating and circulating T cells in e-cigarette exposed mice showed increased levels of immune checkpoints including CTLA4 and PD-1. Treatment with anti-CTLA4 antibody was able to abrogate metastasis with no detrimental effects on its ability to induce tumor regression in exposed mice. These findings suggest that the major components used in e-cigarette fluid can impact tumor development through induced immunosuppression.

Evaluation and comparison of DNA alkylation and oxidative damage in e-cigarette and heated tobacco users

OBJECTIVES

This study, aimed to determine and compare DNA damage in e-cigarette and HTP (IQOS) users by assessing DNA-adducts, which are biomarkers of various DNA alkylation and oxidation.

METHODS

For the evaluation of DNA alkylation, N3-Ethyladenine (N3-EtA) and N3-Methyladenine (N3-MeA) adducts were used. DNA oxidation was assessed using, 8-hydroxy-2'-deoxyguanosine(8-OHdG). The urinary cotinine, N3-MeA, N3-EtA, and 8-OHdG concentrations of the cigarette smokers (n:39), e-cigarette users (n:28), IQOS users (n:20), passive smokers (n:32), and nonsmokers(n:41) who lived Ankara, Turkiye were determined using, liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

In light of the detected 8-OHdG levels, e-cigarette (3.19 ng/g creatinine) and IQOS (4.38 ng/g creatinine) users had higher oxidative DNA damage than healthy nonsmokers (2.51 ng/g creatinine). Alkylated DNA-adducts were identified in the urine of e-cigarette (N3-MeA: 3.92 ng/g creatinine; N3-EtA: 0.23 ng/g creatinine) and IQOS (N3-MeA: 7.54 ng/g creatinine; N3-EtA: 0.29 ng/g creatinine) users. In the generation of N3-MeA adducts, a significant difference was found between IQOS users and e-cigarette users (p < 0.05). Also, DNA alkylation in flavored e-cigarette users (N3-MeA: 4.51 ng/g creatinine; N3-EtA: 0.27 ng/g creatinine) was higher than in non-flavored e-cigarette users (N3-MeA: 2.27 ng/g creatinine; N3-EtA: 0.06 ng/g creatinine). The highest cotinine levels were found in cigarette smokers (16.1316 ng/g creatinine). No significant difference was found when e-cigarette (1163.02 ng/g creatinine) and IQOS smokers were compared (1088.3 ng/g creatinine).

CONCLUSION

People who use e-cigarettes and IQOS may be at higher risk of genotoxicity than those who do not use and are not exposed to any tobacco products. Furthermore, the usage of flavoring additives in e-cigarettes contributed to additional genotoxic damage risks.

Effects of Combustible Cigarettes and Heated Tobacco Products on Systemic Inflammatory Response in Patients with Chronic Inflammatory Diseases

Smoke derived from combustible cigarettes (CCs) contains numerous harmful chemicals that can impair the viability, proliferation, and activation of immune cells, affecting the progression of chronic inflammatory diseases. In order to avoid the detrimental effects of cigarette smoking, many CC users have replaced CCs with heated tobacco products (HTPs). Due to different methods of tobacco processing, CC-sourced smoke and HTP-derived aerosols contain different chemical constituents. With the exception of nicotine, HTP-sourced aerosols contain significantly lower amounts of harmful constituents than CC-derived smoke. Since HTP-dependent effects on immune-cell-driven inflammation are still unknown, herein we used flow cytometry analysis, intracellular staining, and an enzyme-linked immunosorbent assay to determine the impact of CCs and HTPs on systemic inflammatory response in patients suffering from ulcerative colitis (UC), diabetes mellitus (DM), and chronic obstructive pulmonary disease (COPD). Both CCs and HTPs significantly modulated cytokine production in circulating immune cells, affecting the systemic inflammatory response in COPD, DM, and UC patients. Compared to CCs, HTPs had weaker capacity to induce the synthesis of inflammatory cytokines (IFN-γ, IL-1β, IL-5, IL-6, IL-12, IL-23, IL-17, TNF-α), but more efficiently induced the production of immunosuppressive IL-10 and IL-35. Additionally, HTPs significantly enhanced the synthesis of pro-fibrotic TGF-β. The continuous use of CCs and HTPs aggravated immune-cell-driven systemic inflammation in COPD and DM patients, but not in UC patients, suggesting that the immunomodulatory effects of CC-derived smoke and HTP-sourced aerosols are disease-specific, and need to be determined for specific immune-cell-driven inflammatory diseases.

Cytotoxic effects of the cigarette smoke extract of heated tobacco products on human oral squamous cell carcinoma: the role of reactive oxygen species and CaMKK2

BACKGROUND

The increasing prevalence of heated tobacco products (HTPs) has heightened concerns regarding their potential health risks. Previous studies have demonstrated the toxicity of cigarette smoke extract (CSE) from traditional tobacco's mainstream smoke, even after the removal of nicotine and tar. Our study aimed to investigate the cytotoxicity of CSE derived from HTPs and traditional tobacco, with a particular focus on the role of reactive oxygen species (ROS) and intracellular Ca2+.

METHODS

A human oral squamous cell carcinoma (OSCC) cell line, HSC-3 was utilized. To prepare CSE, aerosols from HTPs (IQOS) and traditional tobacco products (1R6F reference cigarette) were collected into cell culture media. A cell viability assay, apoptosis assay, western blotting, and Fluo-4 assay were conducted. Changes in ROS levels were measured using electron spin resonance spectroscopy and the high-sensitivity 2',7'-dichlorofluorescein diacetate assay. We performed a knockdown of calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) by shRNA lentivirus in OSCC cells.

RESULTS

CSE from both HTPs and traditional tobacco exhibited cytotoxic effects in OSCC cells. Exposure to CSE from both sources led to an increase in intracellular Ca2+ concentration and induced p38 phosphorylation. Additionally, these extracts prompted cell apoptosis and heightened ROS levels. N-acetylcysteine (NAC) mitigated the cytotoxic effects and p38 phosphorylation. Furthermore, the knockdown of CaMKK2 in HSC-3 cells reduced cytotoxicity, ROS production, and p38 phosphorylation in response to CSE.

CONCLUSION

Our findings suggest that the CSE from both HTPs and traditional tobacco induce cytotoxicity. This toxicity is mediated by ROS, which are regulated through Ca2+ signaling and CaMKK2 pathways.

Impact of smoking intensity and device cleaning on IQOS emissions: comparison with an array of cigarettes

SIGNIFICANCE

IQOS is a heated tobacco product that has been widely advertised by Philip Morris International (PMI) as a reduced-exposure product compared with cigarettes. Reduced exposure results from reduced emission of toxicants which could be influenced by product constituents and user behaviour. This study aims to assess the influence of user behaviour, including device cleaning and puffing parameters, on toxicant emissions from IQOS.

METHODS

IQOS aerosols were generated by a smoking machine using the combination of two cleaning protocols (after 1 stick vs 20 sticks) and five puffing regimes (including standard cigarette puffing regimes and IQOS-tailored regimes). The generated aerosols were analysed by targeted methods for phenol and carbonyl quantification, and by chemical screening for the identification of unknown compounds.

RESULTS

Puffing parameters significantly affected phenol and carbonyl emissions while device cleaning had no effect. Harsher puffing conditions like more, longer, and larger puffs yielded higher levels for most toxicant emissions. Comparing the obtained data with data reported by PMI on 50 cigarette brands smoked under different puffing regimes showed various trends for phenol and carbonyl emissions, with IQOS emissions sometimes higher than cigarettes. Also, the chemical screening resulted in the tentative identification of ~100 compounds in the IQOS aerosols (most of limited toxicity data).

CONCLUSION

This study showed that puffing parameters, but not device cleaning, have significant effects on carbonyl, phenol and other emissions. Data analysis highlighted the importance of comparing IQOS emissions with an array of commercial cigarettes tested under different puffing regimes before accepting reduced exposure claims.

A scoping review of the toxicity and health impact of IQOS

This work aims to summarize the current evidence on the toxicity and health impact of IQOS, taking into consideration the data source. On 1 June 2022, we searched PubMed, Web of Science, and Scopus databases using the terms: 'heated tobacco product', 'heat-not-burn', 'IQOS', and 'tobacco heating system'. The search was time-restricted to update a previous search conducted on 8 November 2021, on IQOS data from 2010-2021. The data source [independent, Philip Morris International (PMI), or other manufacturers] was retrieved from relevant sections of each publication. Publications were categorized into two general categories: 1) Toxicity assessments included in vitro, in vivo, and systems toxicology studies; and 2) The impact on human health included clinical studies assessing biomarkers of exposure and biomarkers of health effects. Generally, independent studies used classical in vitro and in vivo approaches, but PMI studies combined these with modeling of gene expression (i.e. systems toxicology). Toxicity assessment and health impact studies covered pulmonary, cardiovascular, and other systemic toxicity. PMI studies overall showed reduced toxicity and health risks of IQOS compared to cigarettes, but independent data did not always conform with this conclusion. This review highlights some discrepancies in IQOS risk assessment regarding methods, depth, and breadth of data collection, as well as conclusions based on the data source.

Research progress and prospect on the safety of heated tobacco products

In recent years, Heated tobacco products (HTP) have gradually entered the market and become more and more popular with consumers because of their low risk (compared with traditional cigarette). With the increasing popularity and proportion of HTP in the international market, people pay more and more attention to the safety evaluation of HTP, but there is still a lack of systematic review of HTP safety research. In this review, the harmful components of HTP, multi-organ functional programming effects (including respiratory system, cardiovascular system, etc.), and mechanism of the effect generation (including oxidative stress, inflammatory response, etc.) were systematically reviewed, the safety effects of HTP and traditional cigarettes were compared in detail, and the shortcomings and future research directions in the field of HTP safety were discussed. In summary, this review conforms to the general trend of contemporary "tobacco and health", helps people to understand and evaluate HTP more systematically, and provides a strong theoretical support and literature basis for the tobacco industry to carry out HTP risk assessment and exposure improvement.

Perception of the oral health risks of passive smoking from traditional cigarettes, electronic cigarettes, and heated tobacco products: A cross-sectional study

INTRODUCTION

Tobacco smoke is a major health risk factor for smokers but also for non-smokers due to passive smoking. These risks come from conventional cigarette smoke but also from aerosol produced by electronic cigarettes and heated tobacco products (HTPs). The aim of this study was to investigate population knowledge about the adverse effects of passive smoking from traditional cigarettes, electronic cigarettes, and HTPs.

METHODS

Between February and October 2023, 504 subjects among the general population responded to a questionnaire with 8 questions in Italian, via a link to the Google Forms platform. The questions related to the oral health effects of active and passive smoking. Descriptive analyses of all variables in the questionnaire were performed, and statistical analyses between variables were carried out using the chi-squared test and Fisher's exact test.

RESULTS

A large subset of individuals interviewed stated that active smoking is harmful to health and consider active smoking more damaging compared with passive smoking (86.3%). The majority believed that passive smoking of cigarettes is more harmful to oral health than passive smoking of HTPs (79.4%) or electronic cigarettes (e-cigarettes) (84.9%).

CONCLUSIONS

Results suggest that most people in this study had good knowledge about the adverse effects of active or passive smoking on health; however, knowledge regarding e-cigarettes and HTPs was poor and confused. These results reveal the complexity of perceptions regarding different types of smoking and the need for further research to fully understand the risks associated with each type of passive smoking.

Heated tobacco product (IQOS) induced pulmonary infiltrates

Background

Heated tobacco products (HTPs) have been marketed as safer alternatives to conventional cigarettes, but emerging evidence suggests potential respiratory risks. We present a case of pulmonary complications associated with IQOS, a popular HTP, contributing to the growing understanding of these risks.

Case description

A 40-year-old chronic smoker switched to IQOS, consuming 1.5 packs per day. He presented with incidental chest radiographic abnormalities and peripheral eosinophilia. Computed tomography of chest revealed pulmonary nodules and ground glass opacities. Bronchoscopy indicated mild eosinophilia. After ruling out other causes, a lung biopsy was recommended but declined. Discontinuation of IQOS led to symptom resolution and radiographic improvement. This case adds to a limited literature on HTP-induced lung injury, with a unique presentation and favorable response to cessation.

Conclusions

The case highlights potential pulmonary complications and the first describing an organizing pattern of lung injury associated with IQOS use, emphasizing the importance of recognizing and discontinuing HTPs in patients with respiratory symptoms or radiographic abnormalities. Further research is needed to elucidate the mechanisms underlying the harmful effects of HTPs and inform public health policies. This case underscores the importance of monitoring and educating individuals about the potential risks of HTPs to respiratory health, especially in the context of smokers switching to these products.

Impact of More Intense Smoking Parameters and Flavor Variety on Toxicant Levels in Emissions of a Heated Tobacco Product

INTRODUCTION

IQOS HEETS are promoted as reduced-risk alternatives to cigarettes. Although some studies have investigated the chemical composition of HEETS emissions, little is known on whether toxicant levels in such emissions are affected by different puffing parameters and flavor varieties. This has important implications when assessing actual human exposure, since IQOS users develop a specific and personalized puffing behavior and may use different HEETS variants.

METHODS

This study measured the levels of nicotine, total particulate matter, carbonyl compounds, and tobacco-specific nitrosamines (TSNAs) in the emissions of nine differently flavored HEETS and two cigarettes (1R6F and Marlboro Red, MR). Emissions from Yellow HEETS, 1R6F, and MR were collected using the World Health Organization Intense smoking regime and four more intense smoking regimes.

RESULTS

Yellow HEETS aerosol contained lower levels of toxicants compared to 1R6F and MR smoke. More intense smoking regimes increased carbonyl release in cigarette smoke, whereas only higher puff frequency led to lower levels of toxicants in Yellow HEETS aerosol. Some HEETS varieties exhibited higher levels of formaldehyde and TSNAs in their aerosols compared to Yellow HEETS.

CONCLUSIONS

Puff frequency was identified as the only smoking parameter that significantly lowered the release of almost all toxicants in Yellow HEETS, whereas a combination of higher puff volume and puff duration led to increased levels of some carbonyls. Differences in toxicant levels between various commercially available HEETS have important implications when assessing their health impact, as their consumption might induce different toxicant exposure and health effects.

IMPLICATIONS

HEETS release about half as much nicotine and substantially lower levels of toxicants compared to cigarettes. Literature data showed that puffing intensity is increased in cigarette smokers switching to HEETS, maybe in reaction to these lower nicotine levels. Our results show a differential impact of increased puff frequency, puff duration, and puff volume in the release of toxicants from HEETS. Thus, industry-independent studies on puff topography are critical to make choices for the most relevant puffing regime for heated tobacco product regulation. Regulators should consider evaluating the health impact of multiple HEETS varieties, as the tobacco filler composition significantly affects the release of certain toxicants.

Critical appraisal of interventional clinical trials assessing heated tobacco products: a systematic review

OBJECTIVE

To critically assess the methodological characteristics and quality of interventional clinical trials investigating the effects of heated tobacco products (HTPs).

DATA SOURCES

Web of Science (Core collection and MEDLINE), Scopus, MedRxiv, ClinicalTrials.gov and ICTRP trial databases and transnational HTP manufacturer online publication libraries were searched for clinical trials on HTPs published between January 2010 and April 2022.

STUDY SELECTION

Interventional clinical trials of any design, in which at least one group of adult participants used a currently marketed HTP, were selected by two reviewers with good or very good agreement.

DATA EXTRACTION

Data relating to trial characteristics and effects of intervention on primary outcomes were extracted using a predesigned form. Risk of bias was assessed using Cochrane's Risk of Bias tool v1.

DATA SYNTHESIS

40 trials were included, 29 of which were tobacco industry affiliated. Methodological characteristics, such as registration, design, setting, comparator interventions, participants, outcomes and analyses, varied between trials, though there were few significant differences between industry-affiliated and independent trials. Of the 40 trials, 33 were judged to be at high risk of bias and 6 at unclear risk of bias. Trial findings were not significantly associated with either affiliation or risk of bias.

CONCLUSIONS

The conduct and reporting of HTP interventional clinical trials were poor in many respects and limited to investigating effects of short-term exposure. These trials fall short of what is needed to determine whether HTPs are beneficial to public health, meaning they may not be a sound basis for tobacco control policy decisions.

Vitamin D deficiency during the coronavirus disease 2019 (COVID-19) pandemic among healthcare workers

BACKGROUND & AIMS

Vitamin D deficiency is a common nutritional problem worldwide that may have worsened during the coronavirus disease 2019 (COVID-19) pandemic. The present study sought to examine the prevalence and correlates of vitamin D deficiency among healthcare workers three years after the start of the COVID-19 pandemic.

METHODS

Participants comprised 2543 staff members from a medical research institute, who completed a questionnaire and donated blood samples in June 2023. 25-hydroxyvitamin D (25[OH]D) levels were measured using an electrochemiluminescence immunoassay. Logistic regression was used to calculate the odds ratio and its 95% confidence interval while adjusting for covariates.

RESULTS

The proportions of participants with vitamin D insufficiency (25[OH]D 20-29 ng/mL) and deficiency (25[OH]D < 20 ng/mL) were 44.9% and 45.9%, respectively. In a multivariable-adjusted model, factors associated with a higher prevalence of vitamin D deficiency included younger age, female sex, fewer hours of daytime outdoor physical activity during leisure time (without regular use of sunscreen), lower intake of fatty fish, no use of vitamin D supplements, smoking, and no alcohol consumption. Occupational factors, including shift work, were not independently associated with vitamin D deficiency.

CONCLUSIONS

Our results suggest that vitamin D insufficiency and deficiency are highly prevalent among healthcare workers. Health education regarding lifestyle modifications for this occupational group are warranted to improve their vitamin D status in the COVID-19 era.

Comparison of emissions across tobacco products: A slippery slope in tobacco control

In this narrative review, we highlight the challenges of comparing emissions from different tobacco products under controlled laboratory settings (using smoking/vaping machines). We focus on tobacco products that generate inhalable smoke or aerosol, such as cigarettes, cigars, hookah, electronic cigarettes, and heated tobacco products. We discuss challenges associated with sample generation including variability of smoking/vaping machines, lack of standardized adaptors that connect smoking/vaping machines to different tobacco products, puffing protocols that are not representative of actual use, and sample generation session length (minutes or number of puffs) that depends on product characteristics. We also discuss the challenges of physically characterizing and trapping emissions from products with different aerosol characteristics. Challenges to analytical method development are also covered, highlighting matrix effects, order of magnitude differences in analyte levels, and the necessity of tailored quality control/quality assurance measures. The review highlights two approaches in selecting emissions to monitor across products, one focusing on toxicants that were detected and quantified with optimized methods for combustible cigarettes, and the other looking for product-specific toxicants using non-targeted analysis. The challenges of data reporting and statistical analysis that allow meaningful comparison across products are also discussed. We end the review by highlighting that even if the technical challenges are overcome, emission comparison may obscure the absolute exposure from novel products if we only focus on relative exposure compared to combustible products.

Impact of FDA endorsement and modified risk versus exposure messaging in IQOS ads: a randomised factorial experiment among US and Israeli adults

BACKGROUND

IQOS was the first heated tobacco product to receive Food and Drug Administration (FDA) authorisation for 'reduced exposure' marketing claims, which has been exploited globally.

METHODS

In November-December 2021, we conducted a survey-based 3×3 factorial experiment among US (n=1128) and Israeli adults (n=1094). We presented: (1) reduced exposure, reduced risk and control messaging and (2) 2 variations of FDA endorsement and control messaging. Each participant was randomly assigned to evaluate 2 ads (displayed on different ad imagery), then completed assessments of perceived relative harm, exposure and disease risk and likelihood of personally trying or suggesting IQOS to smokers. Ordinal logistic regression examined messaging conditions and their interactions, on the 5 outcomes, respectively, adjusting for covariates.

RESULTS

Control (vs reduced exposure) messaging resulted in higher perceived relative harm (adjusted OR (aOR)=1.29, 95% CI=1.12 to 1.48), exposure (aOR=1.34, 95% CI=1.17 to 1.54) and disease risk (aOR=1.23; 95% CI=1.08 to 1.40), and lower likelihood of suggesting IQOS to smokers (aOR=0.85; 95% CI=0.74 to 0.97). Reduced risk (vs exposure) messaging resulted in lower perceived relative harm (aOR=0.86; 95% CI=0.75 to 0.99). One FDA endorsement message ('IQOS (completed) the US FDA examination of tobacco products. FDA concluded that IQOS is a better choice for adult smokers') was associated with greater likelihood of suggesting IQOS to smokers, relative to control (aOR=1.19; 95% CI=1.04 to 1.37). No interactions between risk/exposure messaging and FDA endorsement messaging were found. Additionally, Israeli participants, cigarette users and men perceived lower relative harm and exposure and greater likelihood of trying or suggesting IQOS to smokers.

CONCLUSIONS

Regulators must monitor direct and indirect advertising content of modified risk tobacco product-authorised products and prevent potentially harmful misinterpretations.

Nicotine, Humectants, and Tobacco-Specific Nitrosamines (TSNAs) in IQOS Heated Tobacco Products (HTPs): A Cross-Country Study

Heated Tobacco Products (HTPs) purport to reduce exposure to tobacco-related toxicants compared to combustible cigarettes. This cross-sectional study examined the content of nicotine, two humectants (propylene glycol (PG) and vegetable glycerin (VG)), and four tobacco-specific nitrosamines (TSNAs: NNN, NNK, NAT, and NAB) in the tobacco filler of a popular HTP brand (IQOS). Non-menthol and menthol IQOS sticks were purchased from nine countries between 2017 and 2020 and were classified into two versions ("Bold" and "Light") using Philip Morris's flavor descriptors. The average nicotine concentration was 4.7 ± 0.5 mg/stick, and the highest nicotine concentration was found in products from Japan (5.1 ± 0.2 mg/stick). VG was the dominant humectant found in all sticks, with an average concentration of (31.5 ± 2.3 mg/stick). NNN, NNK, and NAT were substantially higher in the "Bold" sticks than the "Light" sticks. Significant differences between countries for TSNAs were also observed: the NAT and NAB contents were the highest in the "Light" products from Canada (192.5 ± 24.1 and 22.9 ± 1.0 ng/stick, respectively); the NNK concentration was the highest in the "Bold" products from Poland (64.8 ± 7.9 ng/stick); and the highest NNN concentrations were observed in the "Bold" products from South Africa (488.9 ± 26.7 ng/stick). As NNN and NNK are known human carcinogens, and as humectants like PG and VG can degrade into toxic carbonyl compounds upon heating, monitoring the concentration of these chemicals in HTPs is important for protecting users' health and ensuring compliance with regulations.

The online promotion strategies of e-cigarette and heated tobacco product retailers in South Korea following the COVID-19 pandemic: Implications for regulation

INTRODUCTION

The surge in popularity of e-cigarettes and heated tobacco products (HTPs) in South Korea, driven by perceived health benefits and COVID-19-related concerns, has led to increased advertising claims about their safety despite ongoing debates about their health effects. This study explores the marketing strategies of online e-cigarette and HTP retailers in South Korea pre- and post-COVID-19, examining potential misleading claims and providing a foundation for future regulatory measures.

METHODS

We conducted a comprehensive study of eight major e-commerce platforms and three dominant search engines in South Korea to analyze the marketing and advertising strategies of e-cigarettes and heated tobacco products (HTPs) (n=774). Using specific keywords, promotional strategies were identified and categorized, after which statistical analysis was conducted to understand the frequency and proportion of these strategies, highlighting differences between HTP and e-cigarette sellers.

RESULTS

Our analysis reveals a significant rise in the number of online retailers selling e-cigarettes and HTPs following the COVID-19 pandemic, with the promotional strategies 'Stay home and vape' and 'Trendy' being the most prevalent. Trends also indicate a shift in promotional strategies over the years, with a marked increase in health reassurance themes and appeals to trendiness, particularly targeting female consumers, which were used significantly more at HTPs stores.

CONCLUSIONS

The study highlights the need for stricter regulation due to the potential health risks posed by the aggressive marketing strategies of e-cigarette and HTP online retailers in South Korea, amplified by the COVID-19 pandemic.

Aerosol Emissions from Heated Tobacco Products: A Review Focusing on Carbonyls, Analytical Methods, and Experimental Quality

We provide an extensive review of 17 independent and industry-funded studies targeting carbonyls in aerosol emissions of Heated Tobacco Products (HTPs), focusing on quality criteria based on the reproducibility of experiments, appropriate analytic methods, and puffing regimes. Most revised studies complied with these requirements, but some were unreproducible, while others failed to consider analytical variables that may have affected the results and/or produced unrealistic comparisons. We also provide a review of the literature on the physicochemical properties of heated tobacco and HTP aerosols, as well as the evaluation of HTPs by regulatory agencies, addressing various critiques of their relative safety profile. The outcomes from the revised studies and regulatory evaluations tend to agree with and converge to a general consensus that HTP aerosols expose users to significantly lower levels of toxicity than tobacco smoke.

Development and validation of a method for preparing heated tobacco product aerosol condensate (HTPAC) for large-scale toxicity data acquisition

A method of preparing heated tobacco product aerosol condensate (HTPAC) was developed to expedite HTP toxicity evaluation, and the effectiveness was assessed. To prepare HTPAC, HTP aerosol was generated and collected using a Cambridge filter (particulate phase) and Dulbecco's phosphate buffered saline (DPBS; gaseous phase). The aerosol collected on the Cambridge filter was extracted using methanol, which was thereafter removed by nitrogen purging. The HTP aerosol residue was mixed with DPBS loaded with the collected HTP vapor, ultimately yielding HTPAC. Nicotine and formaldehyde, key harmful compounds in HTP aerosol, were detected in HTPAC (901 ± 224 and 22.2 ± 3.90 µg stick-1, respectively, comparable to those in HTP aerosol (990-1350 (nicotine) and 2.33-21.9 µg stick-1 (formaldehyde)). Propylene glycol and vegetable glycerin, which influence the amount of HTP aerosol, were detected at similar levels in HTPAC and HTP aerosol (propylene glycol = 616 ± 57.1 (HTPAC) and 320-630 µg stick-1 (aerosol) and vegetable glycerin = 2418 ± 224 (HTPAC) and 1667-4000 µg stick-1 (aerosol)). Known components of HTP aerosol (hydroxyacetone, acetic acid, triacetin, and 2-furanmethanol) were also detected in HTPAC. Consequently, HTPAC offers an effective method for concentrating harmful compounds found in HTP aerosols. This, in turn, facilitates comprehensive toxicity assessments, paving the way for guidelines ensuring the safe utilization of HTP.

Relationship between heated tobacco product use and allergic rhinitis in Korean adults

INTRODUCTION

Combustible cigarette (CC) smoking is a risk factor for chronic obstructive pulmonary disease (COPD) and asthma, and some studies reported that tobacco smoking might affect the development or symptom control of allergic rhinitis, sinusitis, and atopic dermatitis. However, evidence on the health risks of heated tobacco products (HTPs) is lacking. We investigated the prevalence of respiratory and allergic diseases according to tobacco use types in Korean adults.

METHODS

We used data from 18230 adults in the Korea National Health and Nutrition Examination Survey. Multiple logistic regression analyses were performed to assess the prevalence of respiratory and allergic diseases according to tobacco use types (current exclusive CC use, current exclusive HTPs use, and dual use of CC and HTPs).

RESULTS

The prevalence of exclusive CC users, exclusive HTPs users, dual users of CC and HTPs was 15% (n=2740), 1% (n=182), and 2.4% (n=435), respectively. The prevalence of COPD was higher among past tobacco users (AOR=2.37; 95% CI: 1.02-5.51) versus no tobacco use group. The prevalence of asthma was higher among past tobacco users or exclusive CC users (AOR=1.73; 95% CI: 1.26-2.38, and AOR=1.57; 95% CI: 1.08-2.26) versus non-users of tobacco. The prevalence of allergic rhinitis was higher among past tobacco users versus non-users of tobacco (AOR=1.33; 95% CI: 1.13-1.57), and the prevalence of allergic rhinitis was higher among exclusive HTPs users versus non-users of tobacco or exclusive CC users (AOR=1.60; 95% CI: 1.06-2.42, and AOR=1.74; 95% CI: 1.14-2.66). The adjusted odds of sinusitis and atopic dermatitis were not significantly different between tobacco use types.

CONCLUSIONS

Exclusive use of HTPs was associated with allergic rhinitis in Korean adults. Further longitudinal studies are needed to clarify the health risk of HTPs.

Determination of chemical constituent yields in e-cigarette aerosol using partial and whole pod collections, a comparative analysis

Literature reports the chemical constituent yields of electronic nicotine delivery systems (ENDS) aerosol collected using a range of aerosol collection strategies. The number of puffs to deplete an ENDS product varies widely, but collections often consist of data from the first 50-100 puffs. However, it is not clear whether these discrete puff blocks are representative of constituent yields over the life of a pod. We aimed to assess the effect of differing aerosol collection strategies on reported yields for select chemical constituents in the aerosol of closed pod-based ENDS products. Constituents analyzed were chosen to reflect important classes of compounds from the Final Premarket Tobacco Product Application Guidance. Yields were normalized to total device mass loss (DML). Collection strategies that consisted of partial pod collection were valid for determining yields of constituents whose DML normalized yields were consistent for the duration of pod life. These included primary aerosol constituents, such as propylene glycol, glycerol, and nicotine, and whole pod yields could be determined from initial puff blocks. However, changes were observed in the yields of some metals, some carbonyl compounds, and glycidol over pod life in a chemical constituent and product dependent manner. These results suggest that collection strategies consisting of initial puff block collections require validation per chemical constituent/product and are not appropriate for chemical constituents with variable yields over pod life. Whole pod collection increased sensitivity and accuracy in determining metal, carbonyl, and glycidol yields compared to puff block-based collection methodologies for all products tested.

How Media Stories in Low- and Middle-Income Countries Discussed the U.S. Food and Drug Administration's Modified Risk Tobacco Product Order for IQOS

INTRODUCTION

In 2020, the U.S. Food and Drug Administration authorized the marketing of IQOS as a modified risk tobacco product (MRTP) with reduced exposure information (reduces exposure to harmful chemicals compared to cigarettes) but prohibited Philip Morris International from making reduced risk claims (reduces risk of disease compared to cigarettes). We aimed to assess how news media in low- and middle-income countries (LMICs) discussed this authorization and whether articles discussed IQOS as a reduced exposure versus reduced risk product.

AIMS AND METHODS

News articles published between July 7, 2020 and January 7, 2021 were obtained by searching Tobacco Watcher (www.tobaccowatcher.org), a surveillance platform for tobacco-related news. Articles were eligible if they were published in an LMIC and mentioned the IQOS MRTP order. Non-English language articles were professionally translated. Articles were double coded to identify country of origin, reduced risk and reduced exposure language, discussions of potential impacts of the authorization on regulations in LMICs, and quotes from tobacco industry and public health stakeholders.

RESULTS

We identified 50 eligible articles published in 20 LMICs. Twenty-six (52%) and 40 (80%) included reduced risk and reduced exposure language, respectively. Twenty-two (44%) discussed potential impacts of the MRTP order on regulations in LMICs. Thirty (60%) included quotes from tobacco industry representatives, 6 (12%) included quotes from public health or medical professionals, and 2 (4%) included both.

CONCLUSIONS

News articles in LMICs frequently misreported the MRTP order by using reduced risk language. The authorization is potentially being used to shape perspectives on tobacco regulations in LMICs. Tobacco control experts need to more frequently share their perspectives with the news media.

IMPLICATIONS

News articles from LMICs frequently misrepresented the IQOS MRTP order by using reduced risk language (reduces harm compared to cigarettes) rather than only using reduced exposure language (reduces exposure to harmful chemicals compared to cigarettes). Many articles referred to IQOS as a "better alternative" to cigarettes without specifically referencing reduced risk. Few articles included perspectives from public health or medical professionals, while most included tobacco industry quotes, suggesting that tobacco control experts need to more frequently engage with the news media. These findings also highlight how the U.S. FDA's actions can potentially shape perspectives on tobacco product regulations in LMICs.

Heated Tobacco Products: Insights into Composition and Toxicity

Heated tobacco products (HTPs) are novel products that allow users to inhale nicotine by heating (350 °C) reconstituted tobacco rather than combustion (900 °C) as in conventional cigarettes. HTP sticks containing reconstituted tobacco come in various flavours such as menthol, citrus, etc., like electronic cigarette liquids. Thus, the composition of HTP aerosol will also vary according to the flavouring agents added. Overall, the content of toxic chemicals in HTP aerosol appears to be lower than in cigarette smoke. However, the concentrations of more than twenty harmful and potentially harmful constituents have been reported to be higher in HTP aerosol than in cigarette smoke. Further, several toxic compounds not detected in cigarette smoke are also reported in HTP aerosol. Thus, the risks of HTP use remain unknown. Most of the available data on the composition and health effects of mainstream HTP aerosol exposure are generated by the tobacco industry. Few independent studies have reported short-term pathophysiological effects of HTP use. Currently available HTP toxicity data are mainly on the pulmonary and cardiovascular systems. Moreover, there are no long-term toxicity data and, therefore, the claims of the tobacco industry regarding HTPs as a safer alternative to traditional combustible cigarettes are unsubstantiated. Furthermore, HTP aerosol contains the highly addictive substance nicotine, which is harmful to the adolescent brain, developing foetuses, pregnant women, and also adults. Hence, comprehensive studies addressing the safety profiling related to long-term HTP use are warranted. With this background, the following review summarizes the current state of knowledge on HTP toxicity on four broad lines: composition of mainstream HTP aerosol compared to traditional combustible cigarette smoke, biomarkers of HTP exposure, health effects of HTP exposure, and the harm reduction aspect.

Effects of IQOS health warnings and modified risk claims among young adult cigarette smokers and non-smokers

INTRODUCTION

Heated tobacco products, including Marlboro IQOS, are available globally. In the USA, IQOS was authorised to be advertised with claims about reduced toxicant exposure relative to cigarettes. The effects of such modified risk claims and health warnings have not been studied among young adult cigarette smokers and non-smokers.

METHODS

In 2020, US young adult (18-30 years, n=1328) cigarette smokers and non-smokers viewed an IQOS ad in a 4 (modified risk claim variations or none) by 3 (warning variations or none) between-subjects experiment. Outcome measures assessed perceived credibility and effectiveness of the health or risk message for discouraging IQOS use, perceived harms, efficacy beliefs, and IQOS use intentions.

RESULTS

Smokers reported significantly higher (p<0.05) perceived credibility, lower perceived effectiveness, higher efficacy beliefs about switching to IQOS and higher intentions to use IQOS than non-smokers. Among smokers, health warnings increased perceived credibility (p<0.001) and effectiveness (p<0.05), but claims did not affect outcomes examined. Among non-smokers, warnings and claims increased perceived credibility, and warnings increased perceived effectiveness (p<0.003). The reduced exposure claim increased non-smokers' intentions to use IQOS (b=0.40, 95% CI 0.07 to 0.73).

CONCLUSIONS

Among young adult smokers, health warnings increased perceived effectiveness at discouraging IQOS use and perceived credibility. Among non-smokers, warnings and claims increased perceived credibility and warnings increased perceived effectiveness, but the Food and Drug Administration-authorised reduced exposure claim increased intentions to use IQOS. Research is warranted to understand how the content of modified risk claims and health warnings for IQOS affects IQOS use in this population.

IQOS marketing strategies in the USA before and after US FDA modified risk tobacco product authorisation

INTRODUCTION

Given that the US Food and Drug Administration (FDA) authorised reduced exposure messaging to be used in IQOS marketing, we examined: (1) IQOS ad content; (2) advertising media channels and (3) changes in advertising efforts over time.

METHODS

We conducted a mixed-methods study regarding IQOS ad content (headlines, themes, images), ad occurrence characteristics (including content, media channels and adspend) in the USA from August 2019 to April 2021 using Numerator advertising/marketing data.

RESULTS

Across 24 unique ads and 591 occurrences (84.6% online, 8.0% print, 7.4% mobile), there was $4 902 110 total adspend (98.9% allocated to print). Across unique ads, occurrences and adspend, prominent themes included 'real tobacco' (45.8%, 47.4%, 30.1%, respectively), less odour/ash (29.2%, 21.0%, 29.9%) and switching from cigarettes (25.0%, 19.5%, 69.4%), and images mainly featured the product alone (58.2%, 61.4%, 99.5%) or with women (25.0%, 19.1%, 0.3%). Per occurrences and adspend, the most prominent media channel themes (eg, magazine/website topics) were technology (19.3%, 10.6%), women's fashion (18.1%, 26.2%), weather/news (9.0%, 15.3%) and entertainment/pop culture/gaming (8.5%, 23.1%). Ad themes appearing only post-FDA authorisation included switching from traditional cigarettes, same-day/home-delivery, convenience (eg, use indoors), reduced exposure to some dangerous substances, science/research and distinction from e-cigarettes. Overall adspend per occurrence increased postauthorisation (p=0.016); the highest adspend per unique ad (69.3% of total) focused on ads featuring reduced exposure.

CONCLUSIONS

Regulatory efforts must be informed by ongoing surveillance of IQOS marketing efforts and its impacts, particularly how specific consumer subgroups (eg, tobacco non-users, women, young people) are impacted by marketing exposure.

Impact of different health warning label and reduced exposure messages in IQOS ads on perceptions among US and Israeli adults

Heated tobacco products (HTPs; e.g., IQOS) are advertised as safer than cigarettes or an alternative, yet required health warning labels (HWLS) in many countries, including the US and Israel, do not consider whether HTP ads undermine HWLs, particularly those that do not explicitly address HTPs. In 2021, a randomized 4 × 3 factorial experiment among 2,222 US and Israeli adults examined IQOS ads with differing: 1) HWLs (i.e., smoking risks, prompt to quit, HTP-specific, control); and 2) ad messages (i.e., slight distancing: "cigarette-like satisfaction, no odor", clear distancing: "looking for an alternative?", control). Outcomes were perceived relative harm (vs cigarettes), exposure to harmful chemicals, and disease risk and likelihood of trying or suggesting IQOS to smokers. Ordinal logistic regression was used, adjusted for covariates. One HWL effect was found: risk (vs control) increased perceived relative harm (aOR = 1.21, CI = 1.03-1.41) and exposure (aOR = 1.22, CI = 1.04-1.42) and decreased likelihood of trying IQOS (aOR = 0.82, CI = 0.69-0.97). Both slight and clear distancing ads (vs control) decreased perceived harm (aOR = 0.85, CI = 0.75-0.97; aOR = 0.63, CI = 0.55-0.72, respectively) and increased likelihood of suggesting IQOS to smokers (aOR = 1.23, CI = 1.07-1.41; aOR = 1.28, CI = 1.11-1.47); slight distancing decreased perceived disease risk (aOR = 0.85, CI = 0.75-0.97); and clear distancing decreased perceived exposure (aOR = 0.73, CI = 0.64-0.83). Clear (vs slight) distancing decreased perceived relative harm (aOR = 0.74, CI = 0.65-0.85) and exposure (aOR = 0.82, CI = 0.71-0.93). One interaction effect was found: the quitting HWL and clear distancing led to particularly low perceived relative harm (aOR = 0.63, CI = 0.43-0.93). Regulatory agencies must monitor the impacts of advertising, including reduced risk/exposure messaging on perceptions of HWL messages, to inform future regulatory efforts.

The effects of dual IQOS and cigarette smoke exposure on airway epithelial cells: implications for lung health and respiratory disease pathogenesis

Background

Cigarette smoking remains a primary cause of chronic lung diseases. After a steady decline, smoking rates have recently increased especially with the introduction of newer electronic nicotine delivery devices, and it is also emerging that dual- or poly-product usage is on the rise. Additionally, with the introduction of IQOS (a heated tobacco product) globally, its impact on human health needs to be investigated. In this study we tested if dual exposure (cigarette smoke (CS)+IQOS) is detrimental to lung epithelial cells when compared with CS or IQOS exposure alone.

Methods

Human airway epithelial cells (BEAS-2B) were exposed to either CS, IQOS or their dual combination (CS+IQOS) at concentrations of 0.1%, 1.0%, 2.5% and 5.0%. Cytotoxicity, oxidative stress, mitochondrial homeostasis, mitophagy and effects on epithelial-mesenchymal transition (EMT) signalling were assessed.

Results

Both CS and IQOS alone significantly induced loss of cell viability in a concentration-dependent manner which was further enhanced by dual exposure compared with IQOS alone (p<0.01). Dual exposure significantly increased oxidative stress and perturbed mitochondrial homeostasis when compared with CS or IQOS alone (p<0.05). Additionally, dual exposure induced EMT signalling as shown by increased mesenchymal (α-smooth muscle actin and N-cadherin) and decreased epithelial (E-cadherin) markers when compared with CS or IQOS alone (p<0.05).

Conclusion

Collectively, our study demonstrates that dual CS+IQOS exposure enhances pathogenic signalling mediated by oxidative stress and mitochondrial dysfunction leading to EMT activation, which is an important regulator of small airway fibrosis in obstructive lung diseases.

Rauchen – Wissenswertes über Tabak und alternative Produkte

Tabakrauchen ist weltweit die häufigste vermeidbare Ursache für Krankheit und vorzeitigen Tod. Rauchen ist keine Life-Style-Entscheidung oder nur eine (schlechte) Angewohnheit. Es ist eine chronische Krankheit, die viele Erkrankungen mitverursacht und aggraviert. Durch das psychoaktive Nikotin ist Rauchen zusätzlich eine Suchterkrankung. Bei der Strategie zur Harm Reduction sollen Raucher die Tabakzigarette durch alternative nikotinhaltige Produkte („Alternative Nicotine Delivery Products“), wie die E-Zigarette oder Tabakerhitzer (Heat-not-burn-Produkte), ersetzen. Tabakkonzerne bewerben im Rahmen ihrer Marketingstrategie diese Produkte mit einer Schadstoffreduktion um 95%. Jedoch stehen unabhängige Forschungen und Langzeitergebnisse diesbezüglich aus. Raucher, die zu derartigen Produkten wechseln, sind durch die fortbestehende Nikotinabhängigkeit weiterhin langfristig den Belastungen durch (kardio)toxische und karzinogene Substanzen ausgesetzt. Die gesundheitlichen Auswirkungen dieser inhalativen Noxen werden dargestellt, wobei die Heat-not-burn-Produkte eine Mittelstellung zwischen der schädlichsten Tabakzigarette und den (möglicherweise) weniger gesundheitsschädlichen E-Zigaretten einnehmen. Das Fortbestehen einer (wenn auch reduzierten) kontinuierlichen Exposition in Verbindung mit einer Nikotinabhängigkeit ist keine Alternative zu einer professionellen evidenzbasierten multimodalen Tabakentwöhnung, die endlich flächendeckend (auch in Deutschland) angeboten werden muss. Ziel sollte der komplette Verzicht auf inhalative Noxen sein, ohne jegliche Toleranz für die Marketingstrategien der Tabakkonzerne.

Reasons for Initiation and Regular Use of Heated Tobacco Products among Current and Former Smokers in South Korea: Findings from the 2020 ITC Korea Survey

South Korea is the world's second-largest heated tobacco product (HTP) market after Japan. HTP sales in South Korea have increased rapidly since May 2017, accounting for 10.6% of the total tobacco market in 2020. Despite this, little is known as to why HTP consumers who were current and former smokers started using HTPs and used them regularly. We analyzed cross-sectional data for 1815 adults (aged 19+) who participated in the 2020 International Tobacco Control (ITC) Korea Survey, of whom 1650 were HTP-cigarette consumers (those who reported smoking cigarettes and using HTPs ≥ weekly) and 165 were exclusive HTP consumers (using HTPs ≥ weekly) who were former or occasional smokers (smoking cigarette < weekly). Respondents were asked to report the reason(s) they used HTPs, with 25 possible reasons for HTP-cigarette consumers and 22 for exclusive HTP consumers. The most common reasons for initiating HTP use among all HTP consumers were out of curiosity (58.9%), family and friends use HTPs (45.5%), and they like the HTP technology (35.9%). The most common reasons for regularly using HTPs among all HTP consumers were that they were less smelly than cigarettes (71.3%), HTPs are less harmful to own health than cigarettes (48.6%), and stress reduction (47.4%). Overall, 35.4% of HTP-cigarette consumers reported using HTPs to quit smoking, 14.7% to reduce smoking but not to quit, and 49.7% for other reasons besides quitting or reducing smoking. In conclusion, several common reasons for initiating and regularly using HTPs were endorsed by all HTP consumers who were smoking, had quit smoking completely, or occasionally smoked. Notably, only about one-third of HTP-cigarette consumers said they were using HTPs to quit smoking, suggesting that most had no intention of using HTPs as an aid to quit smoking in South Korea.

Actual Use Behavior Assessment of a Novel Puff Recording Electronic Nicotine Delivery System: Observation Study

BACKGROUND

Compared with combustible cigarettes, electronic cigarettes (e-cigarettes) can deliver a sufficient amount of nicotine with a significantly reduced emission of toxicants, which renders them as potential harm reduction candidates for tobacco and smoking replacement. However, the use of e-cigarettes is not harm free and the long-term health effect of using e-cigarettes is yet to be established. Given the high prevalence of e-cigarette use across the globe and its potential health concerns, it is imperative to conduct actual use behavior assessments to better understand how e-cigarettes are being consumed in real-world conditions. However, with the currently available technologies, there is still a lack of noninvasive, noninterventional, and convenient instruments for the real-time and real-world use behavior monitoring of e-cigarette product use. Novel technology-based systems that do not primarily rely on self-report or intrusive measurements to monitor e-cigarette use behaviors are therefore highly desired.

OBJECTIVE

The primary goal of this study is to investigate the e-cigarette actual use behaviors in the real world via a novel puff recording electronic nicotine delivery system (PR-ENDS). Specifically, we aim to analyze and summarize the survey and PR-ENDS use data and to study the relationships and effects of different factors on these variables.

METHODS

In real-world conditions, 61 enrolled UK e-cigarette users were instructed to use PR-ENDS as the primary source of nicotine with their selected e-liquids for at least 3 weeks (21 days). A baseline survey was conducted to collect information about participants' demographics and nicotine use history (cigarette and ENDS). The puff data (ie, puff number, puff duration for each puff, device power, e-liquid nicotine concentrations) were directly recorded by PR-ENDS and uploaded to the cloud for further analyses. The nicotine emission and nicotine consumption were estimated based on recorded puff data.

RESULTS

Middle-aged adults with a nicotine history represented the major user profile during the PR-ENDS trial. A wide range of device power and e-liquid nicotine concentrations was applied and their combinations during actual use were found to be rather complex. Various puff parameters (ie, puff duration, puff number, nicotine emission) were assessed with contributing factors from device, e-liquid, and user nicotine history in different effect sizes. The real-time observation revealed substantial intra- and interindividual variabilities in PR-ENDS use behaviors. The use pattern of a quick adaptation followed by consistent product use was recognized for at least 3 weeks during actual use.

CONCLUSIONS

The actual use behavior assessment of PR-ENDS was conducted as a proof-of-concept application. The complex interactions of product attributes and significant intra- and interindividual variabilities in e-cigarette use behaviors provided new insights of compensatory behavior, which can inspire future studies in the field of nicotine addiction and abuse liability behavior assessment.

Chronic exposure to IQOS results in impaired pulmonary function and lung tissue damage in mice

The use of IQOS brand heated tobacco products (HTPs) is increasing worldwide; however, little is known about the long-term effects of HTPs aerosol exposure on the lungs. Herein, we exposed C57BL/6 J mice for 24 weeks to clean air, IQOS aerosol, or cigarette smoke, and determined pulmonary function, lung tissue pathology, inflammation, and oxidative stress. Compared with the control group mice, IQOS group mice showed substantially decreased weight and lung function. Levels of IL-6 and TNF-a, as well as oxidative stress markers, were comparable to those found in the cigarette group. In addition, hematoxylin and eosin staining showed that the alveolar space was enlarged and that emphysema had formed in the IQOS group. Masson staining showed that collagen deposition areas were substantially increased in the airway walls in the IQOS group than in the control group. Immunohistochemical staining showed epithelial-mesenchymal transition in the airways of mice in the IQOS group. In conclusion, chronic exposure to IQOS aerosol results in impaired pulmonary function and lung tissue damage; hence, concern should be raised regarding the long-term safety of this product.

Heated Tobacco Products: Awareness, Beliefs, Use and Susceptibility among US Adult Current Tobacco Users, 2021

Limited data exist on the awareness, beliefs, and use of heated tobacco products (HTPs). Data from 1583 U.S. adult (age ≥ 21 years) current tobacco users were collected in 2021. Participants self-reported HTP awareness, beliefs, use, and susceptibility, as well as current tobacco product use and sociodemographics. We used weighted logistic and multinomial regression models to explore their associations. Overall, 23.6% were aware of, 8.9% had ever used, and 3.0% currently used HTPs. Younger individuals (vs. 61+ years), those with annual income $50,000+ (vs. <$50,000), and those currently using electronic vaping products (vs. non-users) were more likely to be aware of, to have ever used, and to currently be using HTPs (p < 0.05). Black individuals (vs. White) were more likely to report ever and current HTP use (p < 0.05). Current cigarette smoking was not associated with HTP awareness and use (p > 0.05). Holding favorable HTP beliefs was associated with susceptibility to and more advanced HTP use statuses (p < 0.05). Sociodemographics associated with HTP use may reflect HTP marketing strategies. The lack of association with cigarette smoking suggests HTPs may be unlikely cigarette substitutes. Addressing favorable HTP-related beliefs may prevent dual use.

The extent of harmful volatile organic compounds released when smoking after breaking the flavor capsules of heat-not-burn (HNB) cigarette products

A number of flavored capsule heat-not-burn (FC-HNB) tobacco products such as IQOS, Lil, and Glo have been introduced as a new generation of cigarettes. As they can release various types of volatile organic compounds (VOCs), it is important to assess the harmfulness associated with their use. Thus, the composition of VOCs in HNB cigarette vapor was evaluated to investigate the interactive roles of key variables controlling the relationships between VOC composition and capsule breaking, particularly the compositional changes induced by capsule breaking and release of flavor from FC-HNB cigarettes relative to regular products. As the capsules of FC-HNB cigarettes were broken, the total VOC concentrations increased by as high as eight times from 60.3 ± 0.48 to 488 ± 21.8 μg cig^-1. The key VOC components released after breaking the flavored capsules were identified as ethyl butyrate (157 ± 13.6 μg cig^-1; Lil), isoamyl acetate (76.9 ± 1.98 μg cig^-1; Lil), and limonene (52.3 ± 3.29 μg cig^-1; Glo). If the primary health risks of FC-HNB cigarette vapor are assessed using National Institute for Occupational Safety & Health (NIOSH) guidelines, 2,3-butanedinone exceeds the maximum daily intake limit (i.e., 0.05 mg day^-1). Our study is expected to offer valuable insights into the harmful effects of direct and indirect exposure to various VOCs in FC-HNB products.

Effect of a hypothetical modified risk tobacco product claim on heated tobacco product use intention and perceptions in young adults

INTRODUCTION

Modified risk tobacco product (MRTP) claims for heated tobacco products (HTPs) that convey reduced exposure compared with conventional cigarettes may promote product initiation and transition among young people. We assessed the effects of a hypothetical MRTP claim for HTPs on young adults' intention and perceptions of using HTPs and whether these effects differed by their current cigarette and e-cigarette use.

METHODS

We embedded a randomised between-subjects experiment into a web-based survey administered among a cohort of 2354 Southern California young adults (aged 20-23) in 2020. Participants viewed depictions of HTPs with an MRTP claim (n=1190) or no claim (n=1164). HTP use intention and HTP-related harm and use perceptions relative to cigarettes and e-cigarettes were assessed.

RESULTS

Overall, participants who viewed versus did not view the claim did not differ in HTP use intention (28.5% vs 28.7%) but were more likely to perceive HTPs as less harmful than cigarettes (11.4% vs 7.0%; p<0.001). The experimental effect on HTP use intention did not differ among past 30-day cigarette smokers versus non-smokers (interaction adjusted OR (AOR)=0.78, 95% CI 0.36 to 1.76) but differed among past 30-day e-cigarette users versus non-users (interaction AOR=1.67, 95% CI 1.02 to 2.68).

DISCUSSION

The hypothetical MRTP claim may lower young adults' HTP harm perceptions compared with cigarettes but may not change HTP use intention overall or differentially for cigarette smokers. The larger effect on HTP use intention among e-cigarette users than non-users raises the question of whether MRTP claims may promote HTP use or HTP and e-cigarette dual use among young e-cigarette users.

Le tabac chauffé est-il un outil de réduction des risques ?

Heated tobacco (HT), a new tobacco product, is presented by the tobacco industry as an effective and safe alternative to cigarettes. Even if the quantities of harmful compounds emitted by HT are lower than those found in cigarette smoke, this reduction in exposure cannot be equated with a reduction in risk. No study has provided evidence that switching from cigarettes to HT reduces the risk of tobacco-related diseases. HT cannot be considered as a cigarette cessation product and was even designed as a product to initiate or return to tobacco consumption. To promote this product, the tobacco industry essentially exploits the concept of harm reduction and, as such, tries in its commercial communication to create confusion between HT and electronic cigarettes, despite these two products having nothing in common. This promotion is based, on the one hand, on the data of internal studies in contradiction with those of independent studies, and, on the other, illegally, on social networks and communication in contradiction with the statements of regulation authorities. HT is a new lure offered by the tobacco industry, intended to maintain its profits in a world that is moving away from "traditional" cigarettes. It should be strictly advised against for both non-smokers and smokers.

Heat-not-burn tobacco products and cardiovascular risk reduction: A systematic review of randomized controlled trials

BACKGROUND

Heat-not-burn (HNB) technology by the U.S. Food and Drug Administration has been classified as a modified risk tobacco product, which can be a better option for those populations who cannot give up the habit of smoking. The outlook on the effects of these products is quite controversial in the scientific world.

OBJECTIVE

To present the effect of HNB tobacco products on the cardiovascular system, with reference to the existence of possible benefits of the technology.

METHODS

The literature search was conducted in PubMed/Medline, the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov databases, with reliance on a well-defined guiding research statement. Quality appraisal was performed using the CASP checklist for randomized controlled trials.

RESULTS

The search of three databases identified 167 records, and after selection process, 25 randomized controlled trials were eligible for our study's criteria. Twenty studies investigated the effects of HNB products on biomarkers of clinical relevance. Five studies evaluated other functional heart parameters rather than biomarkers.

CONCLUSION

With HNB tobacco products, significant reductions were found in biomarkers of exposure and biological effect related to pathways involved in cardiovascular disease, including inflammation, oxidative stress, lipid metabolism, platelet function, and endothelial dysfunction.

Exposure to Heated Tobacco Products Aerosol Causes Acute Stress Responses in the Lung of Mouse

In the present study, we evaluated the acute response of mice exposed to IQOS aerosol, a brand-name heated tobacco product (HTP), in the lung tissue. First, the thiobarbituric acid-reactive substances (TBA-RS) value was measured as an index to assess oxidative stress, and a significant increase was observed after exposure, followed by a significant increase in the total lung GSH concentration. The stress responses induced by IQOS aerosols was then analyzed by focusing on the changes in Nrf2 and ATF4, which are transcription factors that induce the expression of genes involved in GSH biosynthesis or metabolism. Although Nrf2 activation was not observed, significant accumulation of ATF4 in the nuclear fraction was noted three hours after exposure to IQOS aerosols. Upon an examination of changes in factors in the GSH biosynthetic system, a significant increase in cystine concentration in the lung tissue was measured, and an increase in xCT expression level was observed in the cell membrane fraction three-six hours after IQOS exposure. Furthermore, characteristic changes in HO-1, a stress-response protein regulated by ATF4, was discovered six hours after IQOS exposure. Moreover, analysis of the upstream ATF4 regulatory system revealed that phosphorylation of eIF2α was enhanced in the lung cytoplasmic fraction three hours after exposure to IQOS aerosols. These findings suggest that ER stress might be induced as an early response to IQOS aerosol exposure, accompanied by the activation of the eIF2α-ATF4 axis. These intracellular changes have also been reported after exposure to combustible cigarette smoke. Thus, the acute response found in the lungs of mice in the present study demonstrate that the inhalation of aerosols from IQOS elicits a biological response similar to that of combustible cigarette smoke. In conclusion, our results provide evidence that the biological effects of HTPs, such as IQOS, cannot be ignored in the lungs.

A content analysis of heated tobacco product business in Hong Kong on Facebook

Heated tobacco products (HTPs) are increasingly popular in Hong Kong (HK) even though they have not been formally launched and the sale of duty-not-paid tobacco sticks is illegal. We investigated how Facebook was used against regulations to sell HTPs in HK. We screened Facebook pages run by HTP businesses targeting HK users in June 2019 and included pages with over 300 "Likes" for inductive content analysis by coding their "About" descriptions and all posts including comments published since January 2017. HTPs included heating devices, accessories, and tobacco sticks. Various attributes were recorded including methods of customer inquiries (telephone, Instant Messaging [IM], address), business responses (comments or private messages, PM), and services provided (warranty/repair). Among 30 pages (50.9% of all 59 eligible pages with related information on HTPs), two-thirds provided phone numbers (66.7%), IM accounts (65.5%), and addresses (66.7%). Most pages sold heating devices (26, 86.7%) and accessories (22, 73.3%) with over 72% providing phone numbers, IM accounts, or addresses. Only 8 pages (26.7%) sold tobacco sticks with 75.0% providing telephone numbers but fewer provided IM accounts (62.5%) and addresses (50.0%). All pages responded using PMs and only 12.5% also used comments. Warranty/repair services were provided by 43.3% of the pages. We found Facebook pages were used as dedicated stores to promote and sell HTPs including heating devices, accessories, and even illicit tobacco sticks in HK, a non-official market.

A Decision-Theoretic Public Health Framework for Heated Tobacco and Nicotine Vaping Products

Markets for nicotine vaping products (NVPs) and heated tobacco products (HTPs) have grown as these products became positioned as harm-reduction alternatives to combusted tobacco products. Herein, we present a public health decision-theoretic framework incorporating different patterns of HTP, NVP, and cigarette use to examine their impacts on population health. Our framework demonstrates that, for individuals who would have otherwise smoked, HTP use may provide public health benefits by enabling cessation or by discouraging smoking initiation and relapse. However, the benefits are reduced if more harmful HTP use replaces less harmful NVP use. HTP use may also negatively impact public health by encouraging smoking by otherwise non-smokers or by encouraging initiation or relapse into smoking. These patterns are directly influenced by industry behavior as well as public policy towards HTPs, NVPs, and cigarettes. While substantial research has been devoted to NVPs, much less is known about HTPs. Better information is needed to more precisely define the health risks of HTPs compared to cigarettes and NVPs, the relative appeal of HTPs to consumers, and the likelihood of later transitioning to smoking or quitting all products. While our analysis provides a framework for gaining that information, it also illustrates the complexities in distinguishing key factors.

Heating Up: How Early Twitter Marketing Gave Rise to Organic Word-of-Mouth About Heated Tobacco Products

Social media are an important marketing platform for emerging tobacco products. Heated tobacco products (HTPs) have been introduced in a limited number of local test markets in the United States as potentially reduced-exposure tobacco products. HTPs can be used to heat tobacco as well as marijuana. However, due to growing digital media promotion of these products, it is possible that public knowledge and purchasing opportunities extend beyond test markets. Research on HTP social media promotion is sparse. The objective of the present study is to assess the amount and characterize the content of HTP-related messages on Twitter. We used keyword rules to collect HTP-related posts from the Twitter Historical Powertrack from 1 August 2016 to 31 July 2021. Posts were coded for type (organic, commercial), promotional strategies (e.g., discounts, event promotion), and marijuana co-use mentions using a combination of machine learning methods and human coding. Keyword filters captured 121,012 relevant tweets posted over the period of data collection, with 46,013 (38.02%) tweets featuring commercial content. Findings revealed that there was a two-fold increase in the monthly volume of messages from August 2016 to July 2021. The proportion of organic tweets increased from 29% of all tweets in August 2016 to 73.5% in July 2021. Approximately 20.6% of tweets included mentions of marijuana, and 5,243 posts (4.3%) contained links to online retailers. Promotional tweets featured event promotion, discounts, reduced harm appeals, and fashion appeals. Tobacco control and substance use prevention initiatives should include efforts to monitor the role of social media in promoting organic word-of-mouth and normalizing novel tobacco products.

Insight into the pulmonary molecular toxicity of heated tobacco products using human bronchial and alveolar mucosa models at air-liquid interface

Heated tobacco products (HTP) are novel nicotine delivery products with limited toxicological data. HTP uses heating instead of combustion to generate aerosol (HTP-smoke). Physiologically relevant human bronchial and alveolar lung mucosa models developed at air-liquid interface were exposed to HTP-smoke to assess broad toxicological response (n = 6-7; ISO puffing regimen; compared to sham; non-parametric statistical analysis; significance: p < 0.05). Elevated levels of total cellular reactive oxygen species, stress responsive nuclear factor kappa-B, and DNA damage markers [8-hydroxy-2'-deoxyguanosine, phosphorylated histone H2AX, cleaved poly-(ADP-Ribose) polymerase] were detected in HTP-smoke exposed bronchial and/or alveolar models. RNA sequencing detected differential regulation of 724 genes in the bronchial- and 121 genes in the alveolar model following HTP-smoke exposure (cut off: p ≤ 0.01; fold change: ≥ 2). Common enriched pathways included estrogen biosynthesis, ferroptosis, superoxide radical degradation, xenobiotics, and α-tocopherol degradation. Secreted levels of interleukin (IL)1ꞵ and IL8 increased in the bronchial model whereas in the alveolar model, interferon-γ and IL4 increased and IL13 decreased following HTP-smoke exposure. Increased lipid peroxidation was detected in HTP-smoke exposed bronchial and alveolar models which was inhibited by ferrostatin-1. The findings form a basis to perform independent risk assessment studies on different flavours of HTP using different puffing topography and corresponding chemical characterization.

Challenges in Predicting the Change in the Cumulative Exposure of New Tobacco and Related Products Based on Emissions and Toxicity Dose-Response Data

Many novel tobacco products have been developed in recent years. Although many may emit lower levels of several toxicants, their risk in the long term remains unclear. We previously published a method for the exposure assessment of mixtures that can be used to compare the changes in cumulative exposure to carcinogens among tobacco products. While further developing this method by including more carcinogens or to explore its application to non-cancer endpoints, we encountered a lack of data that are required for better-substantiated conclusions regarding differences in exposure between products. In this special communication, we argue the case for more data on adverse health effects, as well as more data on the composition of the emissions from tobacco products. Such information can be used to identify significant changes in relevance to health using the cumulative exposure method with different products and to substantiate regulatory decisions.

Nicotine dependence of cigarette and heated tobacco users in Japan, 2019: a cross-sectional analysis of the JASTIS Study

OBJECTIVES

Japan is currently the biggest market of heated tobacco products (HTPs) in the world. Little is known about nicotine dependence among HTP users. Thus, the objective was to assess the association of type of tobacco use and time-to-first-use, a marker of nicotine dependence.

METHODS

A cross-sectional analysis of the 2019 data from an internet cohort study was conducted. The analytical sample consisted of 2147 current (≥1 day use in the past 30 days) HTP and/or conventional cigarette users, aged 25+ years. Marginal structural binomial regression was used to estimate nicotine dependence prevalence ratios (PRs) for each category of tobacco use (exclusive daily cigarette, exclusive HTP (≥1 day), dual HTP+daily cigarette, dual HTP+non-daily cigarette), relative to exclusive, non-daily cigarette smoking.

RESULTS

Using a 5 min cut-off for time-to-first-use, the prevalence of nicotine dependence was higher among dual users of HTP and daily cigarettes (PR=1.38; 95% CI: 1.05 to 1.82) and exclusive, daily cigarette users (PR=1.48; 95% CI: 1.15 to 1.91), relative to exclusive, non-daily cigarette users. However, nicotine dependence among exclusive HTP users, and dual HTP+non-daily cigarette users, did not differ from that of exclusive, non-daily cigarette users. When using 15 and 30 min cut-offs, all types of users, including exclusive HTP, had higher levels of nicotine dependence relative to exclusive, non-daily cigarette users.

CONCLUSIONS

Regardless of HTP use, daily cigarette users had higher prevalence of nicotine dependence compared with non-daily cigarette users. Exclusive HTP users had similar (or potentially higher) dependence compared with exclusive, non-daily cigarette users. Longitudinal studies are needed to interrogate the public health implications of growing HTP use worldwide.