Heated tobacco products: things we do and do not know

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.

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.

Preliminary study on the effect of using heat-not-burn tobacco products on indoor air quality

In this study, the effect of the use of heat-not-burn (HnB) products on indoor air quality (IAQ) was evaluated. To do this, the concentrations of nicotine, propylene glycol (PG), and vegetable glycerin (VG) directly emitted when using HnB products were analyzed and compared to those from conventional cigarettes. Furthermore, the levels of VOCs, aldehydes, nanoparticle, and particulate matter (PM) detected when subjects used HnB products in the exposure chamber were evaluated the effect on IAQ. As a result, the range of nicotine levels transferred by HnB products (0.8-1.2 mg cigarette^-1) is lower than that by conventional cigarettes (2.4-3.6 mg cigarette^-1). On the other hand, the range of VG levels emitted from HnB products (3.1-5.9 mg cigarette^-1) were higher than that emitted from conventional cigarettes (0.6-3.0 mg cigarette^-1). In addition, although the amount generated from HnB products was small compared to those from conventional cigarettes, various kinds of VOCs, aldehydes, nanoparticle and PM were produced, and these were confirmed to affect IAQ.

Feasibility of a primary care patient decision aid for smoking cessation with information about e-cigarettes

•

Patients had higher confidence and readiness to quit after the decision aids.

•

The decision aid helped prepare patients to make a decision about quitting smoking.

•

Patients expressed satisfaction with the decision aid and clinician consultation.

•

Smoking cessation decision aids are acceptable and may promote behavior change.

Decision aids can promote shared decision making and behavior change and may be effective in helping patients quit smoking. Patients are increasingly using e-cigarettes for smoking cessation; however, little is known about the impact of including e-cigarette information in smoking cessation decision aids. Our objective was to assess the feasibility and acceptability of a smoking cessation decision aid including e-cigarette information. This study was conducted at one family medicine clinic in the United States. We used a pre-post design. In Phase I, the decision aid presented information about approved cessation methods. In Phase II, current e-cigarette users and patients with no intention of quitting received additional information on switching to e-cigarettes. We assessed the impact of the decision aids on quit attempts and abstinence, confidence and readiness to quit, confidence and readiness to switch to e-cigarettes, and patient satisfaction. We enrolled 60 patients in each phase (N = 120). Patients reported higher confidence and readiness to quit after viewing the decision aids and consulting with their physician (p < 0.01). Patients reported the decision aid helped prepare them to make a decision about quitting smoking and expressed satisfaction with the decision aid and clinician consultation. We did not observe an impact of including e-cigarette information. Smoking cessation decision aids are acceptable to patients and may promote behavior change. Future studies should explore the impact of providing patients e-cigarette information using larger sample sizes and rigorous designs. Further research is needed to identify strategies to promote shared decision-making regarding e-cigarettes.

Exhalation of alternative tobacco product aerosols differs from cigarette smoke-and may lead to alternative health risks

BACKGROUND

Variation in alternative tobacco product (ATP) constituents, heating potential, and consumer behaviors have made it difficult to characterize their health risks. To date, most toxicity studies of ATPs have used established cigarette endpoints to inform study design. Furthermore, to assess where ATPs fall on the tobacco harm continuum, with cigarettes representing maximum potential risk, studies have tended to compare the relative biological responses to ATPs against those due to cigarettes.

OBJECTIVES

1) To characterize the exhalation profiles of two popular ATPs: electronic cigarettes (e-cigarettes) and hookah waterpipes (hookah) and 2) to determine if ATP exhalation patterns were representative of cigarette exhalation patterns.

METHODS

Exhalation patterns were recorded (mouth only, nose only, or both mouth and nose) among individuals observed in the New York City tri-state area using a recognizable tobacco product (cigarette, e-cigarette, or hookah). Cigarette smokers and e-cigarette vapers were observed on city streets; water-pipe smokers were observed inside Manhattan hookah bars.

RESULTS

E-cigarette vapers practiced exclusive nasal exhalation at far higher rates than did cigarette smokers (19.5% vs 4.9%). Among vapers, e-cigarette device type was also significantly associated with exhalation profile. Overall, cigarette smokers exhaled from their nose approximately half to one-third as often as ATP users (hookah and e-cigarettes, respectively).

CONCLUSIONS

Nasal exhalation of tobacco emissions appears to be a shared characteristic across several types of ATPs. It is therefore plausible that ATP-specific consumer behaviors may foster unique upper respiratory health consequences that have not been observed in smokers. Thus, product-specific behaviors should inform the prioritization of biological endpoints used in studies evaluating ATP toxicity and health effects.

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.

1,2-Propylene Glycol: A Biomarker of Exposure Specific to e-Cigarette Consumption

Over the past decade, new emerging tobacco and nicotine-delivery products have changed the tobacco landscape. Especially, electronic cigarettes (ECs) have been suggested to be considered for tobacco harm reduction, reinforcing the need to identify novel biomarkers of exposure (BoE) specific to the EC use as this would complement exposure assessment and product compliance monitoring. Therefore, a sensitive LC-MS/MS method for the quantification of 1,2-propylene glycol (PG) and glycerol (G), the main e-liquid constituents, was established. PG and G were analyzed in plasma and urine samples from a clinical study comparing five nicotine product user groups, users of combustible cigarettes (CC), electronic cigarettes (EC), heated tobacco products (HTP), oral tobacco (OT), and oral/dermal nicotine delivery products (used for nicotine replacement therapy, NRT) with a control group of non-users (NU). Data demonstrate significantly elevated PG levels in urine and plasma in EC users compared to users of CC, HTP, NRT, OT as well as NU. In addition, PG in plasma and urine of vapers significantly correlated with nicotine (plasma) and total nicotine equivalents (urine), biomarkers reflecting product consumption, emphasizing the high specificity of PG as a BoE for EC consumption. We therefore suggest the use of PG as BoE in urine and/or plasma in order to monitor EC use compliance in exposure assessments.

Oral and periodontal implications of tobacco and nicotine products

Tobacco use contributes to more mortality and morbidity globally than any other behavioral risk factor. Adverse effects do not spare the oral cavity, with many oral diseases more common, and treatments less successful, in the tobacco-using patient. Many of the oral health effects of cigarette smoking are well established, but other forms of tobacco, including cigars and smokeless tobacco, merit dental professionals' attention. Recently, an expanding variety of new or emerging tobacco and/or nicotine products has been brought to market, most prominently electronic cigarettes, but also including heated tobacco and other noncombustible nicotine products. The use of cannabis (marijuana) is increasing and also has risks for oral health and dental treatment. For the practicing periodontist, and all dental professionals, providing sound patient recommendations requires knowledge of the general and oral health implications associated with this wide range of tobacco and nicotine products and cannabis. This review provides an overview of selected tobacco and nicotine products with an emphasis on their implications for periodontal disease risk and clinical management. Also presented are strategies for tobacco use counselling and cessation support that dental professionals can implement in practice.

News Media Presentations of Heated Tobacco Products (HTPs): A Content Analysis of Newspaper and Television News Coverage in South Korea

Our content analysis of newspaper and television news stories in South Korea examines the quantity and nature of news about novel heated tobacco products (HTPs), which heat instead of burn tobacco and that manufacturers claim are less harmful than cigarettes. The amount of news coverage peaked when the government introduced new regulations, suggesting that HTP news was driven largely by new policies. Indeed, HTPs were more likely to be presented as a policy rather than a health issue. When it comes to news sources, government agencies and HTP manufacturers were referenced most often in the news. As for benefits of HTPs, news stories focused on reduced harm, greater social acceptability, and convenience, while discussions of drawbacks included potentially being equally or more harmful than cigarettes, the possibility of extensive future regulations, and HTPs' unknown health effects. Findings suggested that certain journalistic practices, such as relying heavily on established routine sources, focusing on the stories that could attract large audiences, and representing the perspectives of the publishers and the primary audiences, might have affected the nature of HTP discourse.

Cross-sectional study on the awareness, susceptibility and use of heated tobacco products among adolescents in Guatemala City, Guatemala

OBJECTIVES

Heated tobacco products (HTPs) are increasingly marketed worldwide, yet limited research on HTPs has been conducted in low and middle-income countries (LMICs) or among adolescents. Guatemala is one of the few LMICs where HTPs are available. This study examined prevalence and correlates of HTP awareness, susceptibility and use among adolescents in Guatemala.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional survey on HTP awareness, susceptibility and use was conducted among 2870 students between the ages of 13 and 17 in private schools in Guatemala City, Guatemala.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was susceptibility to future use of HTP among school-aged current and never smokers in Guatemala. We also explored awareness and use of HTPs. Multivariate binomial regression models were used to explore associations between these outcomes and both sociodemographic factors and established smoking correlates.

RESULTS

Of all students (n=2870), about half were aware of HTPs (52.4%) and susceptible to future or continued use (52.4%). Whereas 8.4% of students had tried HTPs in the lifetime (but not in the last month), only 2.9% used HTPs in the past month. Independent correlates of HTP susceptibility and ever-use included: use of other tobacco products (current smoking: adjusted OR (AOR)=10.53 and 6.63, respectively; current e-cigarette use: AOR=21.87 and 10.40, respectively), moderate alcohol consumption (AOR=1.49 and 1.19, respectively), marijuana use in the past 30 days (AOR=3.49 and 2.29, respectively) and having friends who use HTPs (AOR=1.83 and 7.28, respectively).

CONCLUSIONS

Among this sample of adolescents in Guatemala City, where tobacco control is weak, the prevalence of HTP use was low but susceptibility to future use was high. Tobacco prevention and intervention strategies for cigarettes and e-cigarettes should now also include HTPs, which tend to be used by similar adolescent populations (ie, those who use other substances or are exposed to tobacco through family and friends).

Awareness and use of heated tobacco products among adult smokers in six European countries: findings from the EUREST-PLUS ITC Europe Surveys

BACKGROUND

The study assessed awareness and use of heated tobacco products (HTPs) and factors that influenced these issues among cigarette smokers from six European countries in 2016 (Wave 1) and 2018 (Wave 2).

METHODS

A survey was conducted among a nationally representative sample of cigarette smokers aged 18 years or older from Germany, Greece, Hungary, Poland, Romania and Spain in 2016 (N = 6011) and 2018 (N = 6027; 53% of smokers from the previous wave were retained, regardless of smoking status and dropouts were replaced by a replenishment sample of smokers). Data were collected through face-to-face interviews. Estimates were produced using weighted data. The study presents the cross-sectional results.

RESULTS

Awareness of HTPs increased from 8% to 17% between the two waves. At Wave 1, 1.1% of the smokers declared having used HTPs at least once during their lifetime; and at Wave 2, this increased to 1.9% (around 1% or less in four countries, except for Greece and Romania where it was around 4%). Factors associated with HTPs use among those who had ever heard about these products at Wave 1 were country of residence, being a daily cigarette smoker and ever use of electronic cigarettes. At Wave 2, ever use of HTPs was significantly higher among those who had tried to quit smoking combustible cigarettes in the last 12 months, had tried electronic cigarettes during lifetime and perceived HTPs as less dangerous than combustible cigarettes; the country of residence was also associated with HTPs use.

CONCLUSION

This study offers insights into the behaviours and perceptions of European adult smokers regarding HTPs, an important emerging issue in the field of tobacco control.

Young Adult Correlates of IQOS Curiosity, Interest, and Likelihood of Use

Objectives

Philip Morris International's heated tobacco product, Marlboro IQOS, is available internationally and will soon be marketed in the U.S. We examined correlates of curiosity, interest, and likelihood to use IQOS among U.S. young adults.

Methods

Young adults ages 18 - 30 years (N = 346) were recruited online, viewed a description of IQOS, and completed measures of sociodemographic characteristics, perceived risks, curiosity, interest, and likelihood to use IQOS.

Results

Males had greater curiosity, interest, and likelihood to use IQOS than females. Individuals with household income of $50,000 - $75,000 were more curious than those with household income of greater than $75,000. Cigarette smokers, e-cigarette and dual users had greater curiosity, interest, and likelihood of use than non-tobacco users. Non-white individuals and older young adults had greater likelihood of use. Greater perceived risks of IQOS were negatively associated with curiosity, interest, and likelihood of use.

Conclusions

Among young adults, IQOS has greater appeal among males, non-white individuals, those who are older, those with household income of $50,000-$75,000, cigarette smokers, e-cigarette and dual users, and those with less perceived risks of IQOS. Research on public education communicating the potential risks of IQOS to vulnerable young adults is warranted.