An epidemiologic review of smokeless tobacco health effects and harm reduction potential

Salivary Oxidative Stress and Antioxidant Capacity in Smokeless Tobacco (Naswar) Users

Background

Naswar, a smokeless tobacco product, commonly consumed in Pakistan, is associated with a 10-fold increase in the risk of oral cancer. However, little is known about Naswar's underlying toxicity mechanisms.

Objective

The current study aimed to investigate the effects of Naswar use on oral health and salivary parameters.

Methods

A case-control study was conducted among Naswar users (n=42) and age-matched healthy controls (n=42) in Pakistan in 2019. Participant data were collected using questionnaires. Decayed, missing, and filled teeth (DMFT) scores were computed during clinical examinations. Unstimulated whole saliva was collected to assess salivary flow rate, pH, and salivary total oxidative stress (TOS)/total antioxidant capacity (TAC) using commercially available kits. Participants' oral health parameters were compared between cases and controls using ANOVA.

Results

No significant differences were observed between the two groups in terms of age, oral health, and hygiene practices and mean DMFT score. Mean salivary pH and the salivary flow rate was significantly (p<0.001) higher in Naswar users (7.7 and 0.71 mL/minute, respectively) than in non-users (6.95 and 0.52 mL/minute, respectively). Although TOS and TAC were not significantly different between the groups, Naswar users generally had a higher TOS (51.6±42 µmol/L) and lower TAC (0.55±0.18 mmol/L) than non-users (TOS 45.5±38.2 µmol/L and TAC 0.57±0.17 mmol/L). Correlational analysis also revealed a significant positive correlation between DMFT score and Naswar use duration (r=0.796, p<0.001) and the number of dips/units consumed each day (r=0.515; p<0.001).

Conclusion

Habitual Naswar use is associated with increased salivary flow rate, pH, and TOS, and reduced TAC levels in Pakistani adults compared to non-users. The pro-oxidant changes may contribute toward deleterious effects of Naswar use including oral cancer.

Differences in Levels of Biomarkers of Potential Harm Among Users of a Heat-Not-Burn Tobacco Product, Cigarette Smokers, and Never-Smokers in Japan: A Post-Marketing Observational Study

Introduction

Cigarette smoking is associated with the risk of certain diseases, but non-combustible products may lower these risks. The potential long-term health effects of the next-generation non-combustible products (heat-not-burn tobacco products (HNBP) or electronic vapor products) have not been thoroughly studied. The present study aimed to investigate the impact of biomarkers of potential harm (BoPH) of one of HNBP (a novel vapor product: NTV (novel tobacco vapor)), under the conditions of actual use.

Aims and Methods

This study was an observational, cross-sectional, three-group, multi-center study. Exclusive NTV users (NTV, n = 259), conventional cigarette smokers (CC, n = 100) and never-smokers (NS, n = 100) were enrolled. Biomarkers of tobacco smoke exposure (cotinine and total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)) and BoPH including parameters of physical pulmonary functions relevant to smoking-related diseases were examined, and subjects answered a questionnaire on cough-related symptoms (J-LCQ) and health-related quality of life (SF-36v2®).

Results

Levels of cotinine, total NNAL and BoPH (high-density lipoprotein (HDL)-cholesterol, triglyceride, sICAM-1, WBC count, 11-DHTXB2, 2,3-d-TXB2, 8-epi-PGF2α, forced expiratory volume in 1 second (FEV1), % predicted value of FEV1 (%FEV1) and maximum midexpiratory flow (FEF_25-75)) were significantly different in the NTV group as compared to levels in CC group (p < .05). Significantly higher levels of cotinine, total NNAL, and 2,3-d-TXB2, and lower levels of FEV1 and %FEV1, were observed among NTV users compared to the NS group.

Conclusion

In a post-marketing study under actual use conditions, BoPH associated with smoking-related disease examined in exclusive NTV users were found to be favorably different from those of CC smokers, a finding attributable to a reduction in exposure to harmful substances of tobacco smoke.

Implications

Cigarette smoking is associated with an increased risk of pulmonary diseases like COPD, cardiovascular diseases, and certain cancers. There is a growing body of evidence that HNBP reduces the exposure associated with smoking and that there is a favorable change in BoPH. However, long-term effects regarding the relative health risks to HNBP users compared to CC smokers have not been examined. This study provides post-marketing data under actual use conditions of the effects on biomarkers of potential harm in NTV, one of HNBP, exclusive users compared to CC smokers and never-smokers. The evidence suggests that exclusive NTV users have favorable levels of BoPH compared to CC smokers, and that is result from a sustained reduction in exposure to harmful substances of tobacco smoke.

Characterization of the Abuse Potential in Adult Smokers of a Novel Oral Tobacco Product Relative to Combustible Cigarettes and Nicotine Polacrilex Gum

Novel noncombustible tobacco products offer adult smokers (ASs) alternatives to combustible cigarettes lower on the continuum of risk; however, the abuse potential of such products has not been well studied. The objective of this study was to evaluate the abuse potential of 2 chewable tobacco‐derived nicotine containing products, VERVE Chews Blue Mint (test 1) and Green Mint (test 2), in ASs compared with own‐brand cigarettes (CIGS) and nicotine polacrilex gum (GUM) using subjective measures and nicotine pharmacokinetics. ASs used the test products during a 5‐day at‐home trial prior to completing an in‐clinic 4‐period randomized crossover study. During the study ASs used test products, CIGS, and GUM once on separate days. Responses to Tobacco/Nicotine Withdrawal and Direct Effects of Product questionnaires were documented, and blood samples were collected to assess nicotine pharmacokinetics during each product use. Nicotine pharmacokinetic parameters (C_max and AUC) were statistically significantly lower with use of test products compared with CIGS and statistically significantly higher compared with GUM. No appreciable differences were noted between the 2 flavors for any of the end points measured. Reductions in maximum urge to smoke and maximum responses to the question “Is the Product ‘Pleasant’ Right Now?” for the test products were statistically significantly lower than CIGS but comparable to GUM. Similar results were observed for responses to other items in the 2 questionnaires. The test products, under the conditions of this study, carry lower abuse potential than own‐brand cigarettes and similar to nicotine polacrilex gum.

Real-World Evidence of Differences in Biomarkers of Exposure to Select Harmful and Potentially Harmful Constituents and Biomarkers of Potential Harm Between Adult E-Vapor Users and Adult Cigarette Smokers

INTRODUCTION

Real-world evidence regarding likely long-term health effects of e-vapor products (EVP) under actual use conditions relative to cigarette smoking is not well studied.

METHODS

In this cross-sectional, observational study, biomarkers of exposure (BOE) to select harmful and potentially harmful constituents and biomarkers of potential harm (BOPH) relevant to smoking-related diseases were measured in exclusive adult EVP users (AEVP, n = 144) and exclusive adult cigarette smokers (AS, n = 73). AEVP used their own brand of EVP for 6+ months following 10+ years of cigarette smoking and AS smoked own brand of cigarettes for 10+ years. Subject recruitment and informed consent were obtained online and urine/blood samples were collected at local clinical laboratories, representing a new paradigm for collecting real-world evidence.

RESULTS

The levels of total NNAL (NNK metabolite), 3-hydroxypropyl mercapturic acid (acrolein metabolite), and carboxyhemoglobin (carbon monoxide measure) were 46% to 86% lower in AEVP compared with AS (p ≤ .0001) as was nicotine equivalents (nicotine and its five metabolites; 36%, p < .01). The levels of some BOPH were significantly lower in AEVP compared with AS for 11-dehydrothromboxane-B2 (29%, p = .04; platelet activation), 8-epi-prostaglandin F2α (23%, p = .02; oxidative stress) and soluble intercellular adhesion molecule-1 (16%, p = .02; endothelial function).

CONCLUSIONS

This study demonstrates the feasibility of a new approach for collecting real-world evidence. Substantially lower levels of BOEs (NNK, nicotine, acrolein, carbon monoxide) and favorable differences in BOPHs (platelet activation, oxidative stress, endothelial function) suggest EVP users may have lower health risks than cigarette smokers.

IMPLICATIONS

Cigarette smoking causes serious diseases. Switching from a combustible tobacco product to a noncombustible product is a potential harm reduction pathway for adult smokers unable or unwilling to quit. Real-world evidence regarding the relative risk of EVP use compared with cigarettes is not well established. This study provides data specific to BOE to tobacco smoke constituents and biomarkers of potential harm collected under actual use conditions in a real-world setting. The totality of evidence suggests that exclusive EVP use may present lower health risk compared with smoking cigarettes.

Cancer Perceptions Among Smokeless Tobacco Users: A Qualitative Study of US Firefighters

Background

Prevalence rates of smokeless tobacco (SLT) use among firefighters are remarkably high and substantially higher than similar occupational groups and the general U.S. population. The purpose of this study was to explore the perspectives of fire service personnel regarding cancer and its associations with tobacco and SLT use.

Methods

This descriptive study used a qualitative approach. Key informant interviews were conducted in 39 career firefighters and fire service administration from across the U.S. Discussion were recorded, transcribed verbatim and transferred to NVivo software for narrative analysis. Topics explored included cancer perceptions, attitudes and beliefs, and cultural factors related to SLT use behaviors. Results: Major themes that emerged among fire service personnel included concerns about cancer and its risk factors including firefighting tasks, such as fire overhaul operations, and from their lifestyle behaviors, such as alcohol and tobacco use. Firefighters also suggested a number of reasons for their increased SLT use, such as fire department tobacco-free policy and fire service culture.

Conclusion

The current study provides a rich foundation for future research, prevention, and intervention efforts for the fire service and research communities regarding tobacco and SLT use and cancer risk. Additional research on firefighters' cancer beliefs deserves future research in order to improve messaging about the risks of cancer due to firefighting.

Activation of PI3K/Akt/NF-kB Signaling Mediates Swedish Snus Induced Proliferation and Apoptosis Evasion in the Rat Forestomach: Modulation by Blueberry

BACKGROUND AND OBJECTIVES

The present study was undertaken to ascertain whether the modulatory effects of blueberries on cell proliferation induced by Swedish snus in the rat forestomach epithelium is mediated via abrogation of the PI3K/Akt/NFκB signaling axis that regulates cell fate decision.

METHODS

The transcript and protein expression of genes involved in cell cycle progression and apoptosis, as well as canonical PI3K/Akt/NF-κB signaling pathways, were analyzed by qRT-PCR, immunoblotting and ELISA. Expression profiling of noncoding RNAs (ncRNAs) that influence PI3K/Akt/NF-κB signaling was undertaken. TUNEL assay was performed using flow cytometry.

RESULTS

Administration of snus induced basal cell hyperplasia in the rat forestomach with increased cell proliferation and inhibition of apoptosis. This was associated with the activation of PI3K/Akt/NFκB signaling. Coadministration of blueberries significantly suppressed snus-induced hyperplasia. Analysis of the molecular mechanisms revealed that blueberries suppress the phosphorylation of Akt, NF-κB and IKKβ, prevent nuclear translocation of NF-κB and modulate the expression of microRNAs that influence PI3K/Akt/NF-κB signaling.

CONCLUSION

Taken together, the results of the current study provide compelling evidence that blueberries exert significant protective effects against snus-induced soft tissue changes in the rat forestomach epithelium mediated by inhibiting key molecular players in the PI3K/Akt/NF-κB signaling axis. Long-term studies on the impact of snus exposure on various cellular processes, signaling pathways, and the interplay between genetic and epigenetic mechanisms are however warranted. The results of this investigation may contribute to the development of protection against soft tissue changes induced by smokeless tobacco in the human oral cavity.

Smokeless tobacco control in 180 countries across the globe: call to action for full implementation of WHO FCTC measures

Smokeless tobacco is consumed by 356 million people globally and is a leading cause of head and neck cancers. However, global efforts to control smokeless tobacco use trail behind the progress made in curbing cigarette consumption. In this Policy Review, we describe the extent of the policy implementation gap in smokeless tobacco control, discuss key reasons on why it exists, and make recommendations on how to bridge this gap. Although 180 countries have agreed that the WHO Framework Convention on Tobacco Control is the best approach to control the demand and supply of smokeless tobacco, only 138 (77%) Parties define smokeless tobacco in their statutes. Only 34 (19%) Parties tax or report taxing smokeless tobacco products, six (3%) measure content and emissions of smokeless tobacco products, and 41 (23%) mandate pictorial health warnings on these products. Although awareness of the harms related to smokeless tobacco is growing in many parts of the world, few Parties collect or present data on smokeless tobacco use under global or national surveillance mechanisms (eg, Global Tobacco Surveillance System and WHO STEPwise). Only 16 (9%) Parties have implemented a comprehensive ban on smokeless tobacco advertisement, promotion, and sponsorships. Globally, a smaller proportion of smokeless tobacco users are advised to quit the use of smokeless tobacco products compared to tobacco users. Use of smokeless tobacco is becoming a global cause of concern, requiring a greater commitment on the full implementation of the WHO Framework Convention on Tobacco Control measures.

Distinct gene expression changes in human peripheral blood mononuclear cells treated with different tobacco product preparations

Cigarette smoking exerts diverse physiological effects including immune suppression. To better characterize the biological effects of different categories of tobacco products, a genome-wide gene expression study was performed. Transcriptomic profiling was performed in PBMCs treated with different equi-nicotine units of aqueous extracts of cigarette smoke (termed Whole Smoke-Conditioned Medium, or WS-CM), or a single dose smokeless tobacco extract (STE) prepared from reference tobacco products. WS-CM induced dose-dependent changes in the expression of several genes. No significant expression differences between low WS-CM and media control were detected. However, transcripts were significantly affected by medium WS-CM (479), high WS-CM (2, 703), and STE (2, 156). The overlap between medium WS-CM and STE, and high WS-CM and STE, was minimal (34 and 65 transcripts, respectively). Hierarchical clustering revealed that gene expression profiles for STE and medium WS-CM co-clustered, while those affected by the high dose of WS-CM clustered distinctly. Functional analysis revealed that WS-CM, but not STE, uniquely affected genes involved in immune cell development and inflammatory response. Cascades of upstream regulators (e.g., TNF, IL1β, NFƙB) were identified for the observed gene expression changes and generally suppressed by WS-CM, but not by STE. Collectively, these findings demonstrate that combustible and non-combustible tobacco products elicit distinct biological effects, which could explain the observed chronic immune suppression in smokers.

Relationships Among Chewing Tobacco, Cigarette Smoking, and Chronic Health Conditions in Males 18-44 Years of Age

As more public places are designated "non-smoking," chewing tobacco could be an alternative choice for tobacco use; however, controversy exists over the long-term health effects associated with it. This study assessed the relationship between chewing tobacco, cigarette smoking, and chronic health conditions in a representative sample of males 18-44 years of age, while controlling for other variables known to be related to tobacco use. This cross sectional analysis used 2013 data from the Behavioral Risk Factor Surveillance System (BRFSS). The results indicated that about 41% of males reported one or more chronic health conditions, and that about 15% used chewing tobacco only, 21% smoked cigarettes only, and 6% did both. From adjusted analyses, those who chewed tobacco only were 49% more likely to report one or more health conditions; those who smoked cigarettes only were 34% more likely to report one or more health conditions; and those who did both were 95% more likely to report at least one health condition. Overall, any combination of tobacco use was significantly and similarly related to the increased prevalence of chronic health conditions in males aged 18-44 years. Although chewing tobacco use may not be as prevalent in the general population as cigarette smoking, clinicians should be aware of the similar health risks associated with all tobacco use at ages younger than may be expected, and encourage cessation of any tobacco use.

Association between iq'mik smokeless tobacco use and cardiometabolic risk profile among Yup'ik Alaska Native people

OBJECTIVE

The traditional lifestyle of Yup'ik Alaska Native people, including a diet abundant in marine-based foods and physical activity, may be cardio-protective. However, iq'mik, a traditional form of smokeless tobacco used by >50% of Yup'ik adults, could increase cardiometabolic (CM) risk. Our objective was to characterize the associations between iq'mik use and biomarkers of CM status (low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], triglycerides [TG], systolic blood pressure [SBP] and diastolic blood pressure [DBP], glycated hemoglobin [HbA1c], fasting blood glucose [FBG], waist circumference [WC], and body mass index [BMI]).

DESIGN

We assessed these associations using data from a cross-sectional sample of Yup'ik adults (n = 874). Current iq'mik use, demographic, and lifestyle data were collected through interviews. Fasting blood samples were collected to measure LDL-C, HDL-C, TG, HbA1c, and FBG. SBP, DBP, WC, and BMI were obtained by physical examination. We characterized the association between current iq'mik use and continuous biomarkers of CM status using multiple approaches, including adjustment for measures of Yup'ik lifestyle and a propensity score.

RESULTS

Based on either adjustment method, current iq'mik use was significantly and positively associated with at least 5% higher HDL-C, and significantly associated but in an inverse direction with multiple biomarkers of CM status including 7% lower TG, 0.05% lower HbA1c, 2% lower FBG, 4% lower WC, and 4% lower BMI. Observed associations for LDL-C, SBP, and DBP varied by adjustment method.

CONCLUSIONS

This inverse association between iq'mik use and cardiometabolic risk status has not been previously reported. Additional research is needed to replicate these findings and explore physiological mechanisms and/or confounding factors.

Cigarettes, Smokeless Tobacco, and Poly-Tobacco Among Workers in Three Dusty Industries

BACKGROUND

Tobacco use remains high among blue-collar workers, the health consequences of which may be compounded by occupational dust exposure. Detailed data on tobacco use among workers in dusty industries are lacking.

METHODS

The 2006 to 2012 National Survey on Drug Use and Health was used to compare current tobacco use prevalence [including cigarettes, smokeless tobacco (SLT), and both (dual use)] among male workers in three dusty industries to all other employed men using bivariate and multivariate analysis.

RESULTS

Smoking rates were high among extraction (39.9%) and construction (38.5%) workers. Increased odds of SLT (odds ratio = 3.3) and dual use (odds ratio = 2.6) were observed among dusty-industry workers compared with other employed men. The prevalence of any tobacco use was unexpectedly high among extraction workers (60.4%).

CONCLUSIONS

Disparities in tobacco use behaviors by industry may point to opportunities for targeted workplace tobacco cessation programs.

Young or adult users of multiple tobacco/nicotine products urgently need to be informed of meaningful differences in product risks

Previously, it has been argued that health information efforts need to inform the public about meaningful differential risks from tobacco/nicotine products. The fact of multiple product use by the same individual further supports this need. When the majority of youth, for example, who use smokeless tobacco are also current tobacco smokers, it makes little sense to mount a smokeless prevention campaign that fails to include clear messages about the much greater risks from smoking. In April 2016, The Food & Drug Administration (FDA) announced a $36 million campaign for youth that "smokeless doesn't mean harmless." Research shows the public (a) already knows that smokeless tobacco is not harmless, but are (b) also largely unaware that cigarettes are much more harmful than smokeless. Though not harmless, smokeless tobacco has been estimated to be over 90% less harmful than cigarettes. 'Gateway' fears are made moot by current use of multiple tobacco/nicotine products. When multi-tobacco product use is commonplace among users, usable information on significant differences in risk is crucial for both adult and younger users. The FDA and like campaigns and health information websites should follow established ethical principles and accepted communication methods to inform the public of less-harmful tobacco/nicotine products as well as the greater harms of smoking, in keeping with the Surgeon-General's advice that reductions in smoking in particular will bring about the greatest public health advances.

Patterns of youth tobacco and polytobacco usage: The shift to alternative tobacco products

BACKGROUND

Despite significant declines in youth cigarette smoking, overall tobacco usage remains over 20% as non-cigarette tobacco product usage is increasingly common and polytobacco use (using 1+ tobacco product) remains steady.

OBJECTIVES

The present study was designed to identify patterns of youth tobacco use and examine associations with sociodemographic characteristics and tobacco dependence.

METHODS

The current analysis uses Latent Class Analysis (LCA) to examine the 6,958 tobacco users (n = 2,738 female) in the National Youth Tobacco Survey (2012 and 2013). We used as indicators past month use of tobacco products (cigarettes, cigars, smokeless tobacco, e-cigarettes, hookah, snus, pipes, bidis, and kreteks) and regressed resulting classes on sociodemographic characteristics and tobacco dependence.

RESULTS

Nine classes emerged: cigarette smokers (33.4% of sample, also included small probabilities for use of cigars and e-cigarettes), cigar smokers (16.8%, nearly exclusive), smokeless tobacco users (12.3%, also included small probabilities for cigarettes, cigars, snus), hookah smokers (11.8%), tobacco smokers/chewers (10.7%, variety of primarily traditional tobacco products), tobacco/hookah smokers (7.2%), tobacco/snus/e-cig users (3.3%), e-cigarette users (2.9%,), and polytobacco users (1.7%, high probabilities for all products). Compared to cigarette smokers, tobacco/hookah smokers and hookah smokers were more likely to report Hispanic ethnicity. Polytobacco users were more likely to report dependence (AOR:2.77, 95% CI:[1.49-5.18]), whereas e-cigarette users were less likely (AOR:0.49, 95% CI:[0.24-0.97]).

CONCLUSION

Findings are consistent with other research demonstrating shifts in adolescent tobacco product usage towards non-cigarette tobacco products. Continuous monitoring of these patterns is needed to help predict if this shift will ultimately result in improved public health.

Shammah (Smokeless Tobacco) and Public Health

Shammah is a preparation of smokeless tobacco (ST) that is frequently used in the Arabian Peninsula, especially in Saudi Arabia. A mixture of powdered tobacco, lime, ash, black pepper, oils and flavorings, shammah in is placed in the buccal cavity or lower labial vestibule of the mouth. The user (or dipper) spits out insoluble debris. ST is linked to a number of harmful effects such as dental disease, oral cancer, oesophagus cancer, and pancreas cancer. It also causes adverse reproductive effects including stillbirth, premature birth and low birth weight. The importation of ST products is prohibited in Saudi Arabia. Legislative action to combat the use of ST (moist snuff and chewing tobacco) in Saudi Arabia appeared in 1990. The actual percentage use may be higher than reported since shammah is illegal in Saudi Arabia and there may be some unwillingness to admit to its use. Data on ST use in the Arabian Peninsula are sparse. Most studies conducted there focused on the prevalence of shammah use among adolescents rather than among adults. This review paper aimed to understand the pattern of use of shammah and its adverse health effects. It also aimed to provide suitable epidemiological data for public health policy makers.

Tobacco Use and Cancer Risk in the Agricultural Health Study

Background: Cigarettes are well known to cause cancer, but less is known about the risks of other tobacco products and use of more than one product.Methods: We examined cancer incidence in relation to exclusive use of six tobacco products [cigarettes, other combustibles (pipe, cigar, cigarillo), and smokeless tobacco (chewing tobacco, snuff)] in the Agricultural Health Study. We also examined the added cancer risks associated with use of cigarettes and other tobacco products.Results: In our study population of 84,015, ever use of smokeless tobacco was higher than the general United States population, whereas cigarette use was lower and other combustible product use was about the same. The strongest associations for exclusive ever use were for lung cancer [cigarettes HR = 15.48; 95% confidence interval (CI), 11.95-20.06; other combustible tobacco HR = 3.44; 95% CI, 1.53-7.71; smokeless tobacco HR = 2.21; 95% CI, 1.11-4.42]. Compared with exclusive cigarette smokers, cigarette smokers who additionally ever-used another combustible product had higher risks of smoking-related cancers (HR = 1.16; 95% CI, 1.04-1.30), especially among those who smoked cigarettes for more than 15 years.Conclusions and Impact: Cigarette smokers who additionally ever used smokeless tobacco had cancer risks similar to exclusive cigarette smokers. Users of cigarettes and other combustible tobacco may have higher risks of certain cancers than exclusive cigarette users. Cancer Epidemiol Biomarkers Prev; 26(5); 769-78. ©2016 AACR.

Exposure and response to current text-only smokeless tobacco health warnings among smokeless tobacco users aged ≥18years, United States, 2012-2013

INTRODUCTION

We assessed US adult smokeless tobacco (SLT) users' exposure and response to SLT health warnings, which are currently in text-only format, covering 30% of the two primary surfaces of SLT containers and 20% of advertisements.

METHODS

Data were from the 2012-2013 National Adult Tobacco Survey. Past 30-day exposure to SLT health warnings among past 30-day SLT users (n=1626) was a self-report of seeing warnings on SLT packages: "Very often," "Often," or "Sometimes" (versus "Rarely" or "Never"). We measured the association between SLT health warning exposure and perceptions of SLT harmfulness and addictiveness using logistic regression.

RESULTS

Of past 30-day SLT users, 77.5% reported exposure to SLT health warnings, with lower prevalence reported among females and users of novel SLT products (snus/dissolvable tobacco). Furthermore, exposure reduced linearly with reducing education and annual household income (p<0.01). Among exposed past 30-day SLT users, 73.9% reported thinking about the health risks of SLT, while 17.1% reported stopping SLT use on ≥1 occasion within the past 30days. Exposure to SLT warnings was associated with perceived SLT harmfulness (AOR=2.16; 95% CI=1.15-4.04), but not with perceived SLT addictiveness.

CONCLUSION

Socioeconomic disparities found in exposure and response to SLT health warnings can be addressed through implementation of large pictorial warnings.

A systematic review of transitions between cigarette and smokeless tobacco product use in the United States

Background

Smokeless tobacco use is becoming an increasingly important public health issue in the US and may influence cigarette smoking behavior. Systematic information on transitions between smokeless tobacco and cigarette use in the US is limited.

Methods

We conducted a systematic review of published literature on transitions between smokeless tobacco and cigarette use in the US. We searched PubMed, Web of Science and EbscoHost databases for all published articles from January 2000 to March 2014 that presented estimates of transitions in US youth and adult study populations over time between at least one of the following tobacco use states: exclusive cigarette smoking, exclusive smokeless tobacco use, dual use of both products, and use of neither product. We excluded non-English language studies, studies published before 2000, clinical trials, controlled cessation programs, and clinical studies or evaluations of smokeless tobacco cessation programs.

Results

The review identified six studies on US populations published since 2000 with longitudinal data on some or all of the transitions that users can undergo between smokeless tobacco and cigarette use. There was considerable heterogeneity across studies in design and tobacco use definitions. Despite these differences, the existing data indicate that switching behaviors from exclusive smoking to exclusive smokeless tobacco use are limited (adults: 0%-1.4%, adolescents: 0.8%-3.8%) but may be more common from exclusive smokeless tobacco use to exclusive smoking (adults: 0.9%-26.6%, adolescents: 16.6%-25.5%). Among adults, exclusive cigarette smoking was generally stable and consistent (79.7% to 87.6%) over follow-up across studies but less stable in adolescents (46.8%-78.7%). Exclusive smokeless tobacco use was less stable than exclusive cigarette smoking over time (adults: 59.4%-76.6%, adolescents: 26.2%-44.8%).

Conclusion

This review provides published estimates of the proportions of adults and adolescents transitioning between tobacco use categories from the most recently available studies on longitudinal transitions between smokeless tobacco and cigarettes in the US. These data can be used to track tobacco use behaviors and evaluate their effect on public health; however, the data for these studies were generally collected more than a decade ago. Additional research including nationally representative longitudinal estimates using consistent definitions and designs, would improve understanding of current tobacco transition behaviors.

Predictors of smokeless tobacco cessation among telephone quitline participants

BACKGROUND

The prevalence of smokeless tobacco use in the U.S. is increasing and its use is a risk factor for a number of adverse health outcomes. Currently, there is limited evidence on the effectiveness of quitlines for tobacco cessation among smokeless tobacco users.

PURPOSE

To examine factors related to tobacco abstinence among exclusive smokeless tobacco users registering for services with the Oklahoma Tobacco Helpline.

METHODS

Participants included 959 male exclusive smokeless tobacco users registering with the Helpline between 2004 and 2012; a total of 374 completed a follow-up survey 7 months post-registration. Data were collected between 2004 and 2013 and included baseline data at Helpline registration, services received, and 7-month follow-up for 30-day point-prevalence for tobacco abstinence. Univariate and multiple logistic regression examined associations between abstinence and participant characteristics, intensity of Helpline intervention, and behavioral factors. ORs and 95% CIs were reported. Analyses were completed in 2013.

RESULTS

At the 7-month follow-up, 43% of the participants reported 30-day abstinence from tobacco. Each additional completed Helpline call increased the likelihood of tobacco cessation by 20% (OR=1.20, 95% CI=1.05, 1.38). Smokeless tobacco users with higher levels of motivation to quit at baseline were twice as likely to be abstinent than those with low or moderate levels of motivation (OR=2.05, 95% CI=1.25, 3.35). Use of nicotine replacement therapy was not associated with abstinence when adjusted for Helpline calls, income, and level of motivation.

CONCLUSIONS

Tobacco quitlines offer an effective intervention to increase smokeless tobacco abstinence.

Combusted but not smokeless tobacco products cause DNA damage in oral cavity cells

The aim of this work was to investigate genomic DNA damage in human oral cavity cells after exposure to different tobacco product preparations (TPPs). The oral carcinoma cell line 101A, gingival epithelial cells HGEC, and gingival fibroblasts HGF were exposed to TPM (total particulate matter from 3R4F cigarettes), ST/CAS (2S3 smokeless tobacco extract in complete artificial saliva), and NIC (nicotine). Treatments were for 24 h using TPM at its EC-50 doses, ST/CAS and NIC at doses with equi-nicotine units, and high doses for ST/CAS and NIC. Comet assays showed that TPM, but not ST/CAS or NIC, caused substantial DNA breaks in cells; only the high ST/CAS dose caused weak DNA damage. These results were confirmed by immunofluorescence for γ-H2AX protein. These data revealed that the combusted TPP caused substantial DNA damage in all cell types, whereas the two non-combusted TPPs exerted no or only minimal DNA damage. They support epidemiologic evidence on the relative risk associated with consumption of non-combusted versus combusted tobacco products, and help to understand potential genotoxic effects of such products on oral cavity cells.

Predictors and patterns of cigarette and smokeless tobacco use among adolescents in 32 countries, 2007-2011

PURPOSE

This study compared data from 32 countries to assess predictors and patterns of cigarette and smokeless tobacco (SLT) use among students aged 13-15 years old.

METHODS

Data from the 2007-2008 Global Youth Tobacco Surveys were analyzed for students aged 13-15 years in 31 countries located in all six World Health Organization regions. In addition, the 2011 National Youth Tobacco Survey was analyzed for U.S. students aged 13-15 years. Country-specific prevalence of current smoking, current SLT use, and concurrent use patterns were assessed.

RESULTS

The national prevalence of current cigarette smoking among students aged 13-15 years ranged from 1.8% (Rwanda) to 32.9% (Latvia), whereas current SLT use ranged from 1.1% (Montenegro) to 14.4% (Lesotho). In the U.S. and most European countries surveyed, current smoking prevalence was significantly higher than SLT prevalence, in contrast to patterns observed in low- and middle-income countries. Also, in most of the surveyed countries outside of Europe and the United States, SLT use among girls was as common as their use of cigarettes, and not significantly different from use by boys. When compared with U.S. adolescents, the odds of SLT use were highest among African adolescents (adjusted odds ratio = 3.98; 95% CI: 2.19-7.24) followed by those in the Southeast Asian region (adjusted odds ratio = 2.76; 95% CI: 1.38-5.53).

CONCLUSIONS

Region-specific patterns of tobacco use were noticed. Furthermore, it is alarming that in several low- and middle-income countries, the prevalence of SLT use among females did not differ from that among males, suggesting the possibility of a future shared burden of disease between both males and females.

Clinical and biochemical studies support smokeless tobacco's carcinogenic potential in the human oral cavity

In 2007, the International Agency for Research on Cancer presented compelling evidence that linked smokeless tobacco use to the development of human oral cancer. Although these findings imply vigorous local carcinogen metabolism, little is known about levels and distribution of phase I, II, and III (drug egress) enzymes in human oral mucosa. In this study here, we integrated clinical data, and imaging and histopathologic analyses of an oral squamous cell carcinoma that arose at the site of smokeless tobacco quid placement in a patient. Immunoblot and immunohistochemical (IHC) analyses were used to identify tumor and normal human oral mucosal smokeless tobacco-associated metabolic activation and detoxification enzymes. Human oral epithelium contains every known phase I enzyme associated with nitrosamine oxidative bioactivation with approximately 2-fold interdonor differences in protein levels. Previous studies have confirmed approximately 3.5-fold interdonor variations in intraepithelial phase II enzymes. Unlike the superficially located enzymes in nonreplicating esophageal surface epithelium, IHC studies confirmed that oral mucosal nitrosamine metabolizing enzymes reside in the basilar and suprabasilar region, which notably is the site of ongoing keratinocyte DNA replication. Clearly, variations in product composition, nitrosamine metabolism, and exposure duration will modulate clinical outcomes. The data presented here form a coherent picture consistent with the abundant experimental data that link tobacco-specific nitrosamines to human oral cancer.

The development and psychometric evaluation of the Smokeless Tobacco Expectancies Scale (STES)

Expectancies regarding the effects of various psychoactive substances are important predictors of the initiation and maintenance of substance use. Although measures of outcome expectancies exist for several addictive substances, there is currently no measure to assess smokeless tobacco (ST) expectancies in an adult population. This article presents 2 studies leading to the development and psychometric evaluation of the Smokeless Tobacco Expectancies Scale (STES). Initially, 155 individuals listed all outcomes they expected to occur if they were to use ST products. From these responses, an initial pool of potential STES items was identified. The STES was then administered to 2 samples totaling 813 individuals (265 ST users, 270 cigarette smokers, and 278 nontobacco users). The first study included 315 participants who completed a 68-item measure. An exploratory factor analysis identified 10 items that may account for individuals' ST expectancies. Items loaded on 2 factors: Negative Health Consequences and Positive Reinforcement. A confirmatory factor analysis on an independent sample (n = 498) supported the proposed factor structure. Furthermore, in both samples, the STES accurately discriminated ST users from smokers and nonusers. Findings are discussed in terms of the potential uses of the STES for advancing the understanding of ST use.

Differential cell-specific cytotoxic responses of oral cavity cells to tobacco preparations

To examine the effects of standardized (reference) tobacco preparations on human oral cavity cells, two oral squamous cell carcinoma cell lines (101A, 101B) and normal human gingival epithelial cells (HGEC) were treated with cigarette smoke total particulate matter (TPM), smokeless tobacco extracted with complete artificial saliva (ST/CAS), or whole-smoke conditioned media (WS-CM). EC-50 values, as determined by sulforhodamine B assays, varied among the cell types and agents. When normalized to nicotine content, cytotoxicity for WS-CM and TPM was higher compared to that observed with ST/CAS. Nicotine alone had no or only minimal cytotoxicity for all cell types in the applied range. Activation of pro-apoptotic caspase-3 was examined in all cell types at their respective EC-50 doses for the three agents. TPM, but not ST/CAS or WS-CM significantly activated caspase-3 in all three cell types. Fluorescence-activated cell sorting (FACS) for expression of the early apoptosis marker Annexin V and for nuclear staining by 7-aminoactinomycin (7-AAD) revealed different extents of apoptosis versus non-apoptotic cell death for the three agents. These data characterize differential responses of normal and malignant oral cells after exposure to TPM, ST/CAS, or WS-CM. They assist in understanding differential effects of combustible versus non-combustible tobacco products, and in identifying novel biomarkers for tobacco smoke exposure and effect in the oral cavity.

Trends in the use of smokeless tobacco in United States, 2000-2010

OBJECTIVES/HYPOTHESIS

To quantify trends in the use of smokeless tobacco in the United States.

STUDY DESIGN

Longitudinal analysis of national population database.

METHODS

The National Health Interview Surveys for 2000, 2005, and 2010 were analyzed for adult responses to specific questions regarding smokeless tobacco use, which includes chewing tobacco and snuff. Smokeless tobacco lifetime exposure, current use, and frequency of use were determined according to each sampled year, examining for trends over the past decade. Subset analysis for young adults (ages 18-44 years) was conducted. Demographic factors associated with smokeless tobacco use were also determined.

RESULTS

A total of 86,270 adults were surveyed. Among all adults, the proportions of those who had ever tried chewing tobacco were 7.1 ± 0.2%, 8.5 ± 0.2%, and 9.2 ± 0.2% for 2000, 2005, and 2010, respectively (P < .001). Similarly, the proportions of those who had ever tried snuff were 4.4 ± 0.2%, 7.5 ± 0.2%, and 8.4 ± 0.3%, respectively (P < .001). In aggregate, the proportions who were regular users of chewing tobacco remained stable over the survey years: 1.3 ± 0.1%, 1.1 ± 0.1%, and 1.2 ± 0.1%, respectively (P = .382). In contrast, the percentages who were regular users of snuff tobacco increased significantly over the survey years: 1.4 ± 0.1%, 1.6 ± 0.1%, and 2.0 ± 0.1% (P < .001). The proportion of young adults regularly using snuff rose to 2.8 ± 0.2% (P < .001) in 2010. Male sex, non-Hispanic ethnicity, white race, and less than a high school education were characteristics that were strongly associated with smokeless tobacco use.

CONCLUSIONS

There was a trend toward increased smokeless tobacco use, mainly snuff, in the United States in the past decade. This trend was more prominent among young adults and likely will have future health-care implications.

Patterns of snus and cigarette use: a study of Norwegian men followed from age 16 to 19

BACKGROUND

The use of moist snuff (snus) in young Norwegians is increasing, while smoking rates are declining. It is not clear whether snus facilitates smoking.

OBJECTIVE

To assess whether 16-year-old men who were never-smokers, but snus users in 2001, had an increased risk of smoking 3 years later.

METHODS

In a prospective school-based cohort study, 1440 men, who responded to questionnaires in 2001 and 2004, were included in the analyses. The participation rate was 89% in 2001 and 50% in 2004. Multinomial logistic regression models were used to assess the OR of snus users, smokers and dual users of cigarettes and snus, compared with non-tobacco users at baseline, to be smokers at follow-up.

RESULTS

Snus use at baseline was associated with increased odds of dual use at follow-up when the outcome was (1) current dual use versus no tobacco (OR 3.49, 95% CI 1.8 to 6.8) and when the outcome was (2) current dual use versus no smoking but including snus-only use (OR 1.88, 95% CI 1.1 to 3.3). Baseline snus users who were dual users at follow-up seemed to prefer using snus daily and cigarettes occasionally. Use of snus only at baseline was not associated with increased odds of smoking only at follow-up, after adjusting for known risk factors.

CONCLUSIONS

Young men who only used snus at baseline had an increased risk of being dual users at follow-up. Snus use may therefore facilitate smoking.

The in vitro toxicology of Swedish snus

Three commercial brands of Swedish snus (SWS), an experimental SWS, and the 2S3 reference moist snuff were each tested in four in vitro toxicology assays. These assays were: Salmonella reverse mutation, mouse lymphoma, in vitro micronucleus, and cytotoxicity. Water extractions of each of the 5 products were tested using several different concentrations; the experimental SWS was also extracted using dimethyl sulfoxide (DMSO). Extraction procedures were verified by nicotine determinations. Results for SWS in the mutagenicity assays were broadly negative: there were occasional positive responses, but these were effectively at the highest concentration only (concentrations well above those suggested by regulatory guidelines), and were often associated with cytotoxicity. The 2S3 reference was unequivocally positive in one of the three conditions of the micronucleus assay (MNA), at the highest concentration only. Positive controls produced the expected responses in each assay. The SWS data are contrasted with data reported for combusted tobacco in the form of cigarettes, where strongly positive responses have been routinely reported for mutagenicity and cytotoxicity. These negative findings in a laboratory setting concur with the large amount of epidemiological data from Sweden, data showing that SWS are associated with considerably lower carcinogenic potential when compared with cigarettes.

Toxicology of smokeless tobacco: implications for immune, reproductive, and cardiovascular systems

The popularity of smokeless tobacco (ST), or noncombusted tobacco, usually placed within the mouth to be chewed, sucked, or swallowed, is growing rapidly and its prevalence of use is rising globally, due (in part) to greater convenience, as allowable cigarette smoking areas are rapidly decreasing, and increased social acceptability. Though data are limited, ST usage has been directly linked to a number of adverse health outcomes. The potential role that immune dysfunction, including dysregulation of immune cells and their components, may play in the progression of these adverse health outcomes is only just beginning to emerge. Evidence suggesting reproductive outcomes, such as perinatal mortality, preterm birth, and reduced sperm viability, also exists in conjunction with ST use. Cardiovascular health may also be impacted by ST use, resulting in increased blood pressure and endothelial dysfunction, both of which may potentially lead to cardiovascular diseases. This review describes the toxicological implications associated with ST use, with emphasis on immune, reproductive, and cardiovascular outcomes. Epidemiological studies are discussed with respect to experimental studies to help develop the relationship between ST and disease pathology. This review also summarizes the gaps in ST knowledge and potential future directions that are needed to more fully delineate the complex systems driving the adverse health outcomes associated with its use.

Health, masculinity and smokeless tobacco use among college-aged men

Existing work on smokeless tobacco (SLT) often focuses on correlates and predictors of use, ignoring the social and cultural context surrounding initiation and continued use of SLT products. The current study takes a qualitative approach using guided focus groups to examine this unexplored context. The findings show that male SLT users gain social rewards from dipping with other men, and usage is initiated and continued in spite of known potential health consequences. For the men participating in this study SLT use was primarily initiated at social or athletic events with the encouragement of other men and continued for relational maintenance and bonding. Additionally, the men reported that the social rewards received from using SLT far outweighed any potential health consequences or negative social repercussions they might also experience. Implications for future research and health interventions targeting SLT use are discussed.

Who is using snus? - Time trends, socioeconomic and geographic characteristics of snus users in the ageing Swedish population

BACKGROUND

The prevalence of smoking in Sweden has decreased in recent decades, and is now among the lowest in the world. During the same period, the use of Swedish moist oral snuff, a smokeless tobacco called snus, has increased. Few studies have evaluated time trends of the socioeconomic and geographic characteristics of snus users in Sweden. This paper contributes to filling that gap.

METHODS

This study utilized the Linnaeus Database, which links national registers with comprehensive individual data on socioeconomic status (SES) to health data from a large ongoing health survey, the Västerbotten Intervention Programme (VIP). The VIP targets the entire middle-aged population of Västerbotten county at ages 40, 50 and 60 years with yearly cross-sectional surveys including self-reported data on tobacco habits. Time trends of snus use among 92,563 VIP-participants across different areas of residence and smoking groups were investigated graphically. Logistic regression was performed to estimate the associations between SES and geographical variables and current use versus non-use of snus.

RESULTS

Overall, in parallel to decreasing smoking, the increasing trend of snus use in this middle-aged population continues, particularly in 40-year-olds. In both genders, the highest prevalence of snus use was observed among previous smokers. The prevalence of snus use also increased over time among smokers, and was consistently higher compared to those who had never smoked. Among males - both those who had never smoked and previous smokers - low education (OR 1.21, 95%CI 1.06-1.40 and OR 1.28, 95%CI 1.14-1.43), living alone (OR 1.16, 95%CI 1.07-1.27 and OR 1.13, 95%ci 1.04-1.23), low income and living in rural areas was associated with using snus, while this was not seen among male current smokers. Among women, living alone was associated with using snus irrespective of smoking habits. Among female smokers, the OR for snus use increased with higher education.

CONCLUSIONS

A disadvantaged social profile and also higher prevalence in rural areas is observed among male snus users who had never smoked or were previous smokers. Among male smokers there was no association between SES and use of snus. The prevalence of snus use among women is increasing, but is still considerably lower than that of men. The association between snus and SES characteristics is less pronounced among women, although snus is clearly linked to living alone. These patterns should be taken into consideration in tobacco control policies.

Guggulsterone targets smokeless tobacco induced PI3K/Akt pathway in head and neck cancer cells

Background

Epidemiological association of head and neck cancer with smokeless tobacco (ST) emphasizes the need to unravel the molecular mechanisms implicated in cancer development, and identify pharmacologically safe agents for early intervention and prevention of disease recurrence. Guggulsterone (GS), a biosafe nutraceutical, inhibits the PI3K/Akt pathway that plays a critical role in HNSCC development. However, the potential of GS to suppress ST and nicotine (major component of ST) induced HNSCC remains unexplored. We hypothesized GS can abrogate the effects of ST and nicotine on apoptosis in HNSCC cells, in part by activation of PI3K/Akt pathway and its downstream targets, Bax and Bad.

Methods and Results

Our results showed ST and nicotine treatment resulted in activation of PI3K, PDK1, Akt, and its downstream proteins - Raf, GSK3β and pS6 while GS induced a time dependent decrease in activation of PI3K/Akt pathway. ST and nicotine treatment also resulted in induction of Bad and Bax phosphorylation, increased the association of Bad with 14-3-3ζresulting in its sequestration in the cytoplasm of head and neck cancer cells, thus blocking its pro-apoptotic function. Notably, GS pre-treatment inhibited ST/nicotine induced activation of PI3K/Akt pathway, and inhibited the Akt mediated phosphorylation of Bax and Bad.

Conclusions

In conclusion, GS treatment not only inhibited proliferation, but also induced apoptosis by abrogating the effects of ST / nicotine on PI3K/Akt pathway in head and neck cancer cells. These findings provide a rationale for designing future studies to evaluate the chemopreventive potential of GS in ST / nicotine associated head and neck cancer.

Summary of the epidemiological evidence relating snus to health

Interest in snus (Swedish-type moist snuff) as a smoking alternative has increased. This wide-ranging review summarizes evidence relating snus to health and to initiation and cessation of smoking. Meta-analyses are included. After smoking adjustment, snus is unassociated with cancer of the oropharynx (meta-analysis RR 0.97, 95% CI 0.68-1.37), oesophagus (1.10, 0.92-1.33), stomach (0.98, 0.82-1.17), pancreas (1.20, 0.66-2.20), lung (0.71, 0.66-0.76) or other sites, or with heart disease (1.01, 0.91-1.12) or stroke (1.05, 0.95-1.15). No clear associations are evident in never smokers, any possible risk from snus being much less than from smoking. "Snuff-dipper's lesion" does not predict oral cancer. Snus users have increased weight, but diabetes and chronic hypertension seem unaffected. Notwithstanding unconfirmed reports of associations with reduced birthweight, and some other conditions, the evidence provides scant support for any major adverse health effect of snus. Although some claims that snus reduces initiation or encourages quitting are unsoundly based, snus seems not to increase initiation, as indicated by few smokers using snus before starting and current snus use being unassociated with smoking in adults (the association in children probably being due to uncontrolled confounding), and there are no reports that snus discourages quitting.