Chemical and toxicological characteristics of conventional and low-TSNA moist snuff tobacco products

Intake of tobacco nitrosamines of smokers in various provinces of China and their cancer risk: A meta-analysis

Nitrosamines are a class of carcinogens which have been detected widely in food, water, some pharmaceuticals as well as tobacco. The objectives of this paper include reviewing the basic information on tobacco consumption and nitrosamine contents, and assessing the health risks of tobacco nitrosamines exposure to Chinese smokers. We searched the publications in English from "Web of Science" and those in Chinese from the "China National Knowledge Infrastructure" in 2022 and collected 151 literatures with valid information. The content of main nitrosamines in tobacco, including 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosonornicotine (NNN), N-nitrosoanatabine (NAT), N-nitrosoanabasine (NAB), total tobacco-specific nitrosamines (TSNA), and N-nitrosodimethylamine (NDMA) were summarized. The information of daily tobacco consumption of smokers in 30 provinces of China was also collected. Then, the intakes of NNN, NNK, NAT, NAB, TSNAs, and NDMA via tobacco smoke were estimated as 1534 ng/day, 591 ng/day, 685 ng/day, 81 ng/day, 2543 ng/day, and 484 ng/day by adult smokers in 30 provinces, respectively. The cancer risk (CR) values for NNN and NNK inhalation intake were further calculated as 1.44 × 10-5 and 1.95 × 10-4. The CR value for NDMA intake via tobacco smoke (inhalation: 1.66 × 10-4) indicates that NDMA is similarly dangerous in tobacco smoke when compared with the TSNAs. In China, the CR values caused by average nitrosamines intake via various exposures and their order can be estimated as the following: smoke (3.75 × 10-4) > food (1.74 × 10-4) > drinking water (1.38 × 10-5). Smokers in China averagely suffer 200% of extra cancer risk caused by nitrosamines in tobacco when compared with non-smokers.

Comparison of urinary mercapturic acid excretions in users of various tobacco/nicotine products

Urinary mercapturic acids (MAs) are detoxification products for electrophiles occurring in the human body. They are suitable biomarkers of exposure to directly acting electrophilic chemicals or to chemicals which generate the electrophile during its metabolism. We determined the urinary excretion of 19 MAs in habitual users of combustible cigarettes (CCs), electronic cigarettes (ECs), heated tobacco products (HTPs), oral tobacco (OT), and nicotine replacement therapy (NRT) products, and nonusers (NUs) of any tobacco/nicotine products. The 19 MAs are assumed to be physiologically formed primarily from 15 toxicants with three of them belonging to IARC Group 1 (human carcinogen), seven to Group 2A (probable human carcinogen), four to Group 2B (possible human carcinogen), and one to Group 3 (not classifiable as carcinogen). Smoking (CC) was found to be associated with significantly elevated exposure to ethylene oxide (or ethylene), 1,3-butadiene, benzene, dimethylformamide, acrolein, acrylamide, styrene, propylene oxide, acrylonitrile, crotonaldehyde, and isoprene compared with the other user groups and NU. Users of HTPs revealed slight elevation in the MAs related to acrolein, acrylamide, and crotonaldehyde compared with the other non-CC groups. Vaping (EC) was not found to be associated with any of the MAs studied. In conclusion, the determination of urinary MAs is a useful tool for assessing the exposure to toxicants (mainly potential carcinogens) in users of various tobacco/nicotine products. Our data also give cause to clarify the role of vaping (EC) in urinary excretion of DHPMA (precursor: glycidol).

Delineating the Bacteriome of Packaged and Loose Smokeless Tobacco Products Available in North India

Smokeless tobacco product (STP) consumption is a significant public health threat across the globe. STPs are not only a storehouse of carcinogens and toxicants but also harbor microbes that aid in the conversion of tobacco alkaloids to carcinogenic tobacco-specific nitrosamines (TSNAs), thereby posing a further threat to the health of its consumers. The present study analyzed the bacterial diversity of popular dry and loose STPs by 16S rRNA gene sequencing. This NGS-based investigation revealed four dominant phyla Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria and identified 549 genera, Prevotella, Bacteroides, and Lactobacillus constituting the core bacteriome of these STPs. The most significantly diverse bacteriome profile was displayed by the loose STP Mainpuri kapoori. The study further predicted the functional attributes of the prevalent genera by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) algorithm. Genes encoding for nitrate and nitrite reduction and transport enzymes, antibiotic resistance, multi-drug transporters and efflux pumps, secretion of endo- and exotoxin, and other pro-inflammatory molecules were identified. The loose STPs showed the highest level of nitrogen metabolism genes which can contribute to the synthesis of TSNAs. This study reveals the bacteriome of Indian domestic loose STPs that stagger behind in manufacturing and storage stringencies. Our results raise an alarm that the consumption of STPs harboring pathogenic genera can potentially lead to the onset of several oral and systemic diseases. Nevertheless, an in-depth correlation analysis of the microbial diversity of STPs and their elicit impact on consumer health is warranted. KEY POINTS: • Smokeless tobacco harbors bacteria that aid in synthesis of carcinogenic nitrosamines. • Most diverse bacteriome profile was displayed by loose smokeless tobacco products. • Pathogenic genera in these products can harm the oral and systemic health of users.

Urinary Nicotine Metabolites and Self-Reported Tobacco Use Among Adults in the Population Assessment of Tobacco and Health (PATH) Study, 2013-2014

INTRODUCTION

The Population Assessment of Tobacco and Health (PATH) Study is a longitudinal cohort study on tobacco use behavior, attitudes and beliefs, and tobacco-related health outcomes, including biomarkers of tobacco exposure in the U.S. population. In this report we provide a summary of urinary nicotine metabolite measurements among adult users and non-users of tobacco from Wave 1 (2013-2014) of the PATH Study.

METHODS

Total nicotine and its metabolites including cotinine, trans-3'-hydroxycotinine (HCTT), and other minor metabolites were measured in more than 11 500 adult participants by liquid chromatography tandem mass spectrometry methods. Weighted geometric means (GM) and least square means from statistical modeling were calculated for non-users and users of various tobacco products.

RESULTS

Among daily users, the highest GM concentrations of nicotine, cotinine and HCTT were found in exclusive smokeless tobacco users, and the lowest in exclusive e-cigarette users. Exclusive combustible product users had intermediate concentrations, similar to those found in users of multiple products (polyusers). Concentrations increased with age within the categories of tobacco users, and differences associated with gender, race/ethnicity and educational attainment were also noted among user categories. Recent (past 12 months) former users had GM cotinine concentrations that were more than threefold greater than never users.

CONCLUSIONS

These urinary nicotine metabolite data provide quantification of nicotine exposure representative of the entire US adult population during 2013-2014 and may serve as a reference for similar analyses in future measurements within this study.

IMPLICATIONS

Nicotine and its metabolites in urine provide perhaps the most fundamental biomarkers of recent nicotine exposure. This report, based on Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study, provides the first nationally representative data describing urinary nicotine biomarker concentrations in both non-users, and users of a variety of tobacco products including combustible, e-cigarette and smokeless products. These data provide a urinary biomarker concentration snapshot in time for the entire US population during 2013-2014, and will provide a basis for comparison with future results from continuing, periodic evaluations in the PATH Study.

Toxic effects of smokeless tobacco on female reproductive health: A review

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Smokeless tobacco use can lead to impairments of ovarian function, morphology, oocyte quality and hormonal regulation.

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Use of smokeless tobacco during pregnancy has adverse health effects on both the mother and fetus.

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Exposure to smokeless tobacco in utero has long term health consequences on offspring.

The habitual consumption of tobacco in its various form is widespread and a serious public health issue globally. In particular, the use of smokeless tobacco has increased substantially due to its easy availability and misconception that it is relatively harmless compared to smoking. Tobacco use has been well established from numerous studies as a causative agent of devastating illnesses such as cancer, insulin resistance, hypertension, acute respiratory disease, osteoporosis, etc. Limited but growing evidence have also suggested its role in adversely affecting reproductive capabilities and outcomes in women of reproductive age and during pregnancy. This paper provides an updated review on available literature regarding the negative effects of smokeless tobacco use on female reproductive health, during pregnancy and its adverse consequences on the offspring. Existing data suggests the association between chronic smokeless tobacco use and impairment of ovarian morphology and function, oocyte quality, hormonal perturbations, fetal development and long-term health effects on the fetus. Improved understanding of these issues can contribute to better awareness of the dangers of smokeless tobacco products.

Smokeless tobacco and cigarette smoking: chemical mechanisms and cancer prevention

Tobacco products present a deadly combination of nicotine addiction and carcinogen exposure resulting in millions of cancer deaths per year worldwide. A plethora of smokeless tobacco products lead to unacceptable exposure to multiple carcinogens, including the tobacco-specific nitrosamine N'-nitrosonornicotine, a likely cause of the commonly occurring oral cavity cancers observed particularly in South-East Asian countries. Cigarettes continue to deliver a large number of carcinogens, including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons and volatile organic compounds. The multiple carcinogens in cigarette smoke are responsible for the complex mutations observed in critical cancer genes. The exposure of smokeless tobacco users and smokers to carcinogens and toxicants can now be monitored by urinary and DNA adduct biomarkers that may be able to identify those individuals at highest risk of cancer so that effective cancer prevention interventions can be initiated. Regulation of the levels of carcinogens, toxicants and nicotine in tobacco products and evidence-based tobacco control efforts are now recognized as established pathways to preventing tobacco related cancer.

Chemical characteristics and cancer risk assessment of smokeless tobacco used in Tunisia (neffa)

Introduction

neffa, a form of air-dried smokeless tobacco used in North Africa, is spuriously perceived as a lower risk alternative to smoking. The objective of this study was to provide information on some harmful constituents of neffa and to use them for cancer risk assessment.

Methods

a high-performance liquid chromatography method coupled with fluorescence detector was used to determine polycyclic aromatic hydrocarbons (PAHs) in one sample of neffa. An atomic absorption spectrometry was performed to determine the concentrations of lead and cadmium in three samples of neffa. The levels of toxicants found in neffa were used to assess for lifetime cancer risk as advocated by the US Environment Protection Agency.

Results

the determination of PAHs in neffa allowed the identification of phenanthrene and anthracene. However, the higher molecular weight PAHs such as Benzo(a)Pyrene B(a)P were not detected. The concentrations of cadmium and lead varied between 1.3 to 2.8µg/g and 1.7 to 4.6µg/g respectively. Cancer risk for cadmium and lead varied between 4.2E-03 to 9.3E-03 and 2.5E-06 to 6.4E-06 respectively. Cancer risk for Cd exceeded the range of 10E-04 to 10E-06 of an acceptable risk.

Conclusion

neffa is not a healthy alternative for overcoming smoking addiction. It contains mineral and organic pulmonary toxicants. This study could serve as a scientific basis to inform consumers about the products´ toxicity and help them to quit smokeless tobacco (SLT) use.

Identification of biomarkers specific to five different nicotine product user groups: Study protocol of a controlled clinical trial

Background

Assessing biomarker profiles in various body fluids is of large value to discern between the sole use of nicotine products. In particular, the assessment of the product compliance is required for long-term clinical studies. The objective of this study was the identification of biomarkers and biomarker patterns in body fluids, to distinguish between combustibles, heated tobacco products, electronic cigarettes, oral tobacco and oral/dermal nicotine products used for nicotine replacement therapy (NRT), as well as a control group of non-users.

Methods

A controlled, single-center study was conducted with 60 healthy subjects, divided into 6 groups (5 nicotine product user groups and one non-user group) based on their sole use of the products of choice. The subjects were confined for 76 h, during which, free and uncontrolled use of the products was provided. Sample collections were performed according to the study time schedule provided in Table 2. The primary outcome will be validated through analysis of the collected biospecimens (urine, blood, saliva, exhaled breath and exhaled breath condensate) by means of untargeted omics approaches (i.e. exposomics, breathomics and adductomics). Secondary outcome will include established biomarker quantification methods to allow for the identification of typical biomarker patterns. Statistical analysis tools will be used to specifically discriminate different product use categories.

Results/Conclusions

The clinical trial was successfully completed in May 2020, resulting in sample management and preparations for the quantitative and qualitative analyses. This work will serve as a solid basis to discern between biomarker profiles of different nicotine product user groups. The knowledge collected during this research will be required to develop prototype diagnostic tools that can reliably assess the differences and evaluate possible health risks of various nicotine products.

Chemical characterization of tobacco-free "modern" oral nicotine pouches and their position on the toxicant and risk continuums

As compared with cigarette smoking, use of Swedish snus is associated with significantly fewer health risks. Nicotine pouches (NPs), a new form of oral nicotine product, are smokeless and tobacco-free, comprising a nicotine-containing cellulose matrix inside a fiber pouch. NPs are similar in appearance/use to snus, but without tobacco, have the potential to further reduce tobacco-related harm. This study aimed to evaluate toxicant levels of NPs to estimate their position on the tobacco/nicotine product continuums of toxicant delivery and risk. NPs, snus and nicotine replacement therapy products (NRTs) were analyzed for 24-26 compounds applicable to oral tobacco, and their levels were compared. Twenty of these compounds were further used to compare the toxicant profile of NPs, as well as estimated daily toxicant exposure from NP use, with that of tobacco/nicotine products spanning the risk continuum. Of the compounds measured, 22 (NPs), 22 (lozenge NRT), 20 (gum NRT), and 11 (snus) were not quantifiable. Compared with snus, NPs had lower levels of 10 HPHCs and comparable/undetectable levels of a further 13. Across the product categories, NPs and NRTs had the lowest toxicant profiles and estimations of relative toxicant exposure. Based on the present chemical analysis and estimated exposure, use of NPs appears likely to expose users to lower levels of toxic compounds than Swedish snus, which is recognized to offer reduced levels of harm than associated with tobacco smoking. We conclude that NPs should be placed close to NRTs on the tobacco/nicotine product toxicant delivery continuum, although further studies will be needed to confirm this.

Cadmium Intake as a Prognostic Factor in Endometrial Cancer: A Swedish Cohort-Based Study

Metalloendocrinology is a new interdisciplinary field, which was established due to the importance of connections between inorganic chemicals and hormonal mechanisms. The role of cadmium in hormone-related tumors is an excellent example of this connection, as cadmium mimics estrogen in the human body. Since endometrial cancer (EC) is hormone-related, it is well-suited for assessing the estrogenic effects of cadmium. Therefore, the present study aims to explore the role of dietary cadmium intake in the progression-free survival (PFS) and overall survival (OS) in women with EC. Dietary cadmium intake was estimated based on a large cohort of Swedish women (n = 416) with EC. Median dietary cadmium intake was then analyzed in relation to different tumor characteristics and clinical outcomes. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Median daily dietary cadmium intake in the cohort was 13.1 μg (interquartile range 25%-75%=6.4). High dietary cadmium intake (μg/day) was associated with significantly decreased OS in the study cohort (HR = 0.956, 95% CI = 0.914-1.001, p = 0.05). Dietary cadmium intake was not associated with PFS (HR = 0.975, 95% CI = 0.924-1.028, p = 0.348). Therefore, our results indicate that high dietary cadmium intake could be associated with poor outcome in women with EC.

Effects of smokeless tobacco on cell viability, reactive oxygen species, apoptosis, and inflammatory cytokines in human umbilical vein endothelial cells

Smokeless tobacco products provide an alternative to cigarettes; however, smokeless tobacco is carcinogenic and harmful to human health. This study evaluated the toxicological effects of snus extracts and cigarette smoke total particulate matter (TPM) on human umbilical vein endothelial cells (HUVECs). Treated cells were examined for cell viability, reactive oxygen species (ROS), apoptosis, and inflammatory cytokines. Moreover, we explored the mechanism of programmed cell death induced by snus. The results showed that snus extracts significantly inhibited cell viability in a dose-dependent manner. ROS was significantly increased in treatment groups, and anti-oxidant treatment could not prevent snus extract-induced cell death. Snus extracts induced apoptosis, DNA damage, activation and cleavage of caspase-3 and caspase-8, pathway-related gene change, and interleukin (IL)-6 and IL-8 release in HUVECs. Snus extracts exposure may induce cytotoxicity, ROS generation, inflammatory cytokines release, and apoptosis or DNA damage through intrinsic and extrinsic pathways in HUVECs.

An approach for the extract generation and toxicological assessment of tobacco-free 'modern' oral nicotine pouches

Tobacco-free 'modern' oral nicotine pouches (MOPs), are similar in appearance and use to Swedish-style snus, but without tobacco. There are few identified methods to create test samples for toxicologically assessment of MOPs in vitro. In this study we present a simple method for the extraction of pouch material in cell culture media, providing consistent nicotine concentration and easy in vitro assessment. A series of contemporary in vitro screening assays (viability, cell health markers, oxidative stress and genotoxicity) using human oral fibroblasts (HGF) and human lung epithelial cells (H292) were employed. Extracts were generated from LYFT and compared to snus (CRP1.1) and cigarette (1R6F) reference products. MOP and CRP1.1 extracts were generated by incubating one pouch in 20 ml of cell culture media, while 1R6F AqE was prepared by smoking 1 cigarette into 20 ml of cell culture media. 1R6F demonstrated toxicological responses in most assays; CRP1.1 had minimal to moderate effects while MOP demonstrated little or no response in all assays. This study demonstrated the generation of MOPs extracts and their toxicological evaluation using in vitro screening approaches. Future product usage, pharmacokinetics and clinical studies will further substantiate the reduced risk potential of MOPs.

Variability of TSNA in U.S. Tobacco and Moist Smokeless Tobacco Products

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Incoming tobaccos have extremely variable nitrosamine content.

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Blending reduces the variation in tobacco products, but it is still considerable.

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Few, if any, U.S. moist smokeless tobacco products meet the proposed FDA standard.

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Products must be targeted well below the proposed standard to consistently meet it.

Tobacco-specific nitrosamines (TSNAs) have been of concern to the public health community for decades and their reduction through agricultural practices, plant breeding, and tobacco processing has also been a decades-long industry effort. Despite those efforts, TSNAs, though lower, continue to be constituents of concern in tobacco products. This paper examines the TSNA levels of dark air-cured, dark fire-cured, and burley tobaccos purchased in the United States by U.S. Smokeless Tobacco Company LLC (USSTC) and of nine finished USSTC moist smokeless tobacco products. TSNA values of the incoming purchased tobaccos and the finished products showed considerable variability. For the incoming tobaccos, the coefficient of variation was generally more than 100 % for each tobacco type and for each of the measured TSNAs. The relative TSNA variability of the finished tobacco products was also considerable, averaging approximately 25 %. It was also found that the measured values for the finished products averaged well above the proposed FDA NNN proposed product standard of 1.0 μg/g dry weight. Because of the large variability in NNN values, products would have to average well below FDA’s proposed product standard to be consistently compliant.

An exploration of smokeless tobacco product nucleic acids: a combined metagenome and metatranscriptome analysis

Smokeless tobacco (ST) products are used worldwide and are a major public health concern. In addition to harmful chemicals found in these products, microbes found in ST products are believed to be responsible for generating harmful tobacco-specific nitrosamines (TSNAs), the most abundant carcinogens in ST. These microbes also contribute endotoxins and other pro-inflammatory components. A greater understanding of the microbial constituents in these products is sought in order to potentially link select design aspects or manufacturing processes to avoidable increases in harmful constituents. Previous studies looked primarily at bacterial constituents and had not differentiated between viable vs nonviable organisms, so in this study, we sought to use a dual metatranscriptomic and metagenomic analysis to see if differences exist. Using high-throughput sequencing, we observed that there were differences in taxonomic abundances between the metagenome and metatranscriptome, and in the metatranscriptome, we also observed an abundance of plant virus RNA not previously reported in DNA-only studies. We also found in the product tested, that there were no viable bacteria capable of metabolizing nitrate to nitrite. Therefore, the product tested would not be likely to increase TSNAs during shelf storage. We tested only a single product to date using the strategy presented here, but succeeded in demonstrating the value of using of these methods in tobacco products. These results present novel findings from the first combined metagenome and metatranscriptome of a commercial tobacco product.

Rhinologic signs associated with snuff taking

OBJECTIVE

To study rhinologic signs associated with nasal tobacco (snuff) intake in Parakou, northern Benin.

MATERIALS AND METHODS

A cross-sectional descriptive comparative study included 300 tobacco snuff takers and 300 subjects who did not use tobacco at all. The sampling technique was a stratified 4-stage random sample for non-users and a convenience non-random sample for snuff takers.

RESULTS

The sex-ratio was 0.92 in non-users and 41.9 in snuff takers. Duration of snuff taking was more than 20 years in 24.3% of cases. The symptoms studied were significantly more frequent in snuff takers than non-users (P<0.05). Snoring was reported by 58.3% of snuff takers, versus 5.7% of non-users (P=0.000). Nasal obstruction and rhinorrhea were reported by respectively 26.3% and 22.7% of snuff takers, versus 6.3% and 5.3% of non-users (P=0.000). Hyposmia was reported by 14% of snuff takers, versus 1.3% of non-users (P=0.000). Anterior rhinoscopy found abnormalities in 81.7% of snuff takers, compared to 10.67% of non-users. Nasal hypertrichosis was more frequent in snuff takers than non-users: 40% versus 5% (P=0.000).

CONCLUSION

Nasal intake of tobacco is responsible for morbidity in snuff takers compared to non-users of tobacco.

Consortium on Methods Evaluating Tobacco: Research Tools to Inform US Food and Drug Administration Regulation of Snus

Introduction

The US Food and Drug Administration (FDA) has purview over tobacco products. To set policy, the FDA must rely on sound science, yet most existing tobacco research methods have not been designed to specifically inform regulation. The NCI and FDA-funded Consortium on Methods Evaluating Tobacco (COMET) was established to develop and assess valid and reliable methods for tobacco product evaluation. The goal of this article is to describe these assessment methods using a US manufactured "snus" as the test product.

Methods

In designing studies that could inform FDA regulation, COMET has taken a multidisciplinary approach that includes experimental animal models and a range of human studies that examine tobacco product appeal, addictiveness, and toxicity. This article integrates COMET's findings over the last 4 years.

Results

Consistency in results was observed across the various studies, lending validity to our methods. Studies showed low abuse liability for snus and low levels of consumer demand. Toxicity was less than cigarettes on some biomarkers but higher than medicinal nicotine.

Conclusions

Using our study methods and the convergence of results, the snus that we tested as a potential modified risk tobacco product is likely to neither result in substantial public health harm nor benefit.

Implications

This review describes methods that were used to assess the appeal, abuse liability, and toxicity of snus. These methods included animal, behavioral economics, consumer perception studies, and clinical trials. Across these varied methods, study results showed low abuse-liability and appeal of the snus product we tested. In several studies, demand for snus was lower than for less toxic nicotine gum. The consistency and convergence of results across a range of multi-disciplinary studies lends validity to our methods and suggests that promotion of snus as a modified risk tobacco products is unlikely to produce substantial public health benefit or harm.

Tobacco and type 2 diabetes: is the association explained by genetic factors?

BACKGROUND

Smoking and use of Swedish smokeless tobacco (snus) are associated with increased risk of type 2 diabetes (T2D). Our aim was to estimate the unique and shared genetic components of these traits and to what extent the association is explained by shared genetic factors.

METHODS

We used twins of the Swedish Twin Registry who responded to a questionnaire between 1998 and 2006 (n = 40 247) and were followed until 2015 in the National Prescription and Patient Registries. We estimated hazard ratios (HRs) and odds ratios (ORs) for the association between smoking/snus use and T2D (n = 2130) and used structural equation models to estimate genetic and environmental variance components and genetic correlations.

RESULTS

Current smokers [HR 1.69, 95% confidence interval (CI), 1.49-1.92] and snus users (HR 1.19, 95% CI 1.01-1.41) had an increased risk of T2D. In within-pair analyses of monozygotic twins, corresponding ORs were 1.36, 95% CI 0.75-2.46 (smoking) and 1.54, 95% CI 0.80-2.99 (snus). Heritability was 43% (95% CI 36-51) for ever smoking, 58% (95% CI 44- 70) for ever snus use and 66% (95% CI 59-72) for T2D. The genetic correlation with T2D was 18% (95% CI 1-35) for smoking and -6% (95% CI -24 to 4) for snus use, indicating that only a small fraction of the genetic influence is shared.

CONCLUSIONS

We could confirm that consumers of snus and cigarettes are at increased risk of T2D. Both snus use and smoking have strong genetic components, which appears to be attributable primarily to genes that are distinct from those promoting T2D.

GC-MS Analysis and Cytotoxicity Evaluation of Shammah (Smokeless Tobacco) Samples of Jazan Region of Saudi Arabia as Promoter of Cancer Cell Proliferation

Shammah is a locally manufactured form of smokeless tobacco (ST) which is traditionally used in Middle Eastern countries including Saudi Arabia, Sudan, and Yemen. Presence of a high concentration of nicotine, in addition to various other toxic and carcinogenic constituents, makes it a serious human health threat. It is an admixture containing powdered tobacco, along with several additives, such as lime, ash, black pepper, volatile oils, and flavoring agents. This study was conducted to investigate the constituents of eight different samples of widely used shammah varieties in the Jazan region of Saudi Arabia using GC-MS and to evaluate their cytotoxic effect against three cancer cell lines representing most of the top malignancies in the region including MCF-7, A2780, and HT29 cancer cells, in addition to MRC5 cells (normal human fetal lung fibroblast) using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. GC-MS analysis showed the presence of nicotine or 3-(1-methyl-2-pyrrolidinyl)pyridine (2.1–91.9% of total constituents detected) in all ST samples, whereas its derivative (1s,2s)-nicotine-N-oxide (0.23–1.62%) was detected in four samples. In addition, several known carcinogenic constituents were also identified, and their carcinogenicity was confirmed by MTT results, in which, all the eight samples promoted the growth of MCF7, A2780, and HT29 cancer cells. The cytotoxic effects of samples against the normal cells MRC5 was proportional to the number of components detected by GC-MS. The ingestion of these constituents through saliva of shammah consumers could be the reason for many cancers including breast, ovary, and colon cancers. These results support the urgent local and international call to educate the users regarding the deleterious effects of shammah to avoid its use.

Video-based kinetic analysis of calcification in live osteogenic human embryonic stem cell cultures reveals the developmentally toxic effect of Snus tobacco extract

Epidemiological studies suggest tobacco consumption as a probable environmental factor for a variety of congenital anomalies, including low bone mass and increased fracture risk. Despite intensive public health initiatives to publicize the detrimental effects of tobacco use during pregnancy, approximately 10-20% of women in the United States still consume tobacco during pregnancy, some opting for so-called harm-reduction tobacco. These include Snus, a type of orally-consumed yet spit-free chewing tobacco, which is purported to expose users to fewer harmful chemicals. Concerns remain from a developmental health perspective since Snus has not reduced overall health risk to consumers and virtually nothing is known about whether skeletal problems from intrauterine exposure arise in the embryo. Utilizing a newly developed video-based calcification assay we determined that extracts from Snus tobacco hindered calcification of osteoblasts derived from pluripotent stem cells early on in their differentiation. Nicotine, a major component of tobacco products, had no measurable effect in the tested concentration range. However, through the extraction of video data, we determined that the tobacco-specific nitrosamine N'-nitrosonornicotine caused a reduction in calcification with similar kinetics as the complete Snus extract. From measurements of actual nitrosamine concentrations in Snus tobacco extract we furthermore conclude that N'-nitrosonornicotine has the potential to be a major trigger of developmental osteotoxicity caused by Snus tobacco.

Regulation of toxic contents of smokeless tobacco products

Effective regulation of contents of tobacco products is one of the primary milestones to reduce negative health effects associated with the use of smokeless tobacco (SLT) products. As per the available sources, testing of some SLT products has been done on ad hoc basis, but there is a lack of comprehensive and periodic analysis of these products. In addition, the available results indicate huge variations among the levels of pH, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, N-nitrosonornicotine, benzo[a]pyrene, heavy metals and nicotine within different products as well as within different brands of the same product. This review was aimed to throw light on the variations and gaps in testing of SLT products and emphasize the need for strong policy regulation for monitoring the chemical constituents of these products.

SB431542 inhibited cigarette smoke extract induced invasiveness of A549 cells via the TGF-β1/Smad2/MMP3 pathway

Lung cancer has high morbidity and mortality rates. Smoking is involved in the pathogenesis of lung cancer, and tobacco smoke may increase tumor cell invasion and metastasis. The effects of cigarette smoke extract (CSE) on the carcinoma human alveolar basal epithelial A549 cell line were investigated. A549 cells were exposed to increasing concentrations of CSE for 12, 24 and 48 h, and the transforming growth factor-β1 (TGF-β1) signal pathway was inhibited by addition of SB431542, a TGF-β1 receptor antagonist. The proliferation of A549 cells was assayed by a Cell Counting kit-8, invasiveness was assayed using Transwell chambers, and TGF-β1, phosphorylated mothers against decapentaplegic homolog 2 (p-Smad2), and matrix metalloproteinase 3 (MMP3) levels was assessed by western blot analysis. The invasiveness of A549 cells and the expression of TGF-β1, pSmad2, and MMP-3 were significantly increased by CSE (P<0.05). The effects of CSE were abrogated by SB431542 (P<0.05). In conclusion, CSE increased the invasiveness of A549 cells and its effects were abrogated by SB431542 and the TGF-β1/Smad2/MMP-3 pathway may have been involved.

Predictors of mercury, lead, cadmium and antimony status in Norwegian never-pregnant women of fertile age

Background

The toxic trace elements mercury (Hg), lead (Pb), cadmium (Cd) and antimony (Sb) are transferred over the placenta to the fetus and secreted into the breastmilk. All four elements bioaccumulate in the body and as maternal age at delivery is increasing in industrialized countries, the burden of toxic trace elements in never-pregnant women of fertile age is of concern.

Methods

Healthy, never-pregnant women aged 18 to 40 years (n = 158) were recruited between June 2012 and March 2015 in Bergen, Norway. Clinical data were collected and non-fasting venous blood samples were analyzed for whole blood Hg, Pb and Cd and serum Sb by ICP-MS and related to diet and life style factors.

Results

In a multiple linear regression model, increasing age was associated with higher levels of Hg and Sb, but diet and life style factors were more important predictors. Median whole blood Hg was increased by a factor of 70 in women who had fish for dinner ≥1/week, compared to women who rarely or never ate fish (p<0.001). Alcohol intake was the strongest predictor for whole blood Pb, while use of tobacco was the strongest predictor for whole blood Cd. Being a vegetarian was associated with lower levels of both Hg and Sb.

Conclusions

As toxic trace elements tend to bioaccumulate in the body, increasing maternal age at delivery may represent a threat to the next generation. In a group of healthy Norwegian never-pregnant women, age contributed to Hg and Sb levels, but diet and life style factors were stronger determinants of whole blood Hg, Pb, Cd and serum Sb levels. Continuous public actions are needed to reduce modifiable and preventable sources of potentially deleterious toxins to minimize the exposure in children and fertile women.

Greater Sensitivity of Oral Fibroblasts to Smoked Versus Smokeless Tobacco

BACKGROUND

Smokers have an increased incidence and severity of periodontal disease. Although cigarette smoke contains >4,000 chemical components that could affect periodontal tissues, less is understood about the effect of smokeless tobacco. Therefore, this study compares the effects of cigarette smoke extract (CSE) and smokeless tobacco extract (STE) on cell survival and motility of periodontal ligament (PDL) and gingival fibroblasts in vitro.

METHODS

PDL and gingival fibroblasts were exposed to various concentrations of CSE, STE, or nicotine alone. Viable cells were labeled with calcein acetoxymethyl, visualized using fluorescent microscopy, and quantified using a fluorescence multi-well plate reader. In vitro wounding and collagen gel contraction assays were used to assess cell motility.

RESULTS

Both gingival and PDL fibroblasts displayed reduced cell viability with increasing concentrations of CSE and STE. Based on relative nicotine content, CSE was significantly more cytotoxic than STE. PDL fibroblasts were also more sensitive to both CSE and STE compared with gingival fibroblasts. Finally, sublethal doses of CSE reduced cell motility and gel contraction, whereas STE had less effect. Nicotine alone ≤0.5 mM had little to no effect in any of these assays.

CONCLUSIONS

Many of the underlying effects of tobacco products on periodontal tissues may be due to direct inhibition of normal fibroblast function. CSE is found to be more deleterious to the function of both PDL and gingival fibroblasts than STE. PDL fibroblasts appear to be more sensitive to CSE and STE than gingival fibroblasts. Therefore, cigarette smoke may have more profound effects than smokeless tobacco.

Smokeless tobacco (snus) is associated with an increased risk of type 2 diabetes: results from five pooled cohorts

BACKGROUND

Smoking and nicotine exposure increase insulin resistance and the risk of type 2 diabetes. Swedish smokeless tobacco (snus) is high in nicotine, and its use is prevalent in Scandinavian countries, but few studies have investigated snus use in relation to diabetes risk.

OBJECTIVE

To explore the association between snus use and risk of type 2 diabetes using pooled data from five cohorts.

METHODS

Analyses were based on prospective studies conducted between 1990 and 2013 including 54 531 never-smoking men and 2441 incident cases of type 2 diabetes identified through screening, self-reporting and hospital and prescription registries. Hazard ratios (HRs) and 95% confidence intervals (CIs) were assessed and adjusted for age, body mass index, educational level, alcohol consumption and physical activity.

RESULTS

Compared to never users, the HR of type 2 diabetes was 1.15 (95% CI: 1.00-1.32) in current users of snus. In individuals consuming 5-6 boxes per week, the HR was 1.42 (95% CI: 1.07-1.87); in those consuming ≥7 boxes per week, the HR was 1.68 (95% CI: 1.17-2.41). Each additional box of snus consumed per week yielded an HR of 1.08 (95% CI: 1.01-1.16).

CONCLUSION

Our findings indicate that high consumption of snus is a risk factor for type 2 diabetes. The risk was similar to that in smokers, implying that smokers will not reduce their risk of type 2 diabetes by changing to snus use. The results also support the notion that nicotine increases the risk of type 2 diabetes.