Tobacco chewing and adult mortality: a case-control analysis of 22,000 cases and 429,000 controls, never smoking tobacco and never drinking alcohol, in South India

Effects of smokeless tobacco on cancer incidence and mortality: a global systematic review and meta-analysis

INTRODUCTION

The prevalence of smokeless tobacco consumption remains high despite policies on reduction interventions. This study aims to quantify the associations between smokeless tobacco use with cancer incidence and mortality globally.

METHODS

We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and PROSPERO protocol (ID: CRD42023390468). A comprehensive literature search was performed using PubMed, Web of Science, and Scopus databases, covering the period from January 1, 2000, to February 28, 2023. We included peer-reviewed observational studies, specifically case-control and cohort studies, where smokeless tobacco use was the primary exposure and cancer incidence, or mortality were the main outcomes. Three independent reviewers screened titles, abstracts, and full texts, and extracted data from the included studies. Risk of bias was assessed by the same three reviewers. Any disagreements were resolved through discussion with a fourth reviewer. We performed random-effects meta-analyses and assessed heterogeneity and publication bias to ensure the robustness of our findings.

RESULTS

Of the 3,611 articles identified, 80 were included in the final analysis. Increased risks were observed for cancer mortality [Risk Ratio (RR) 1.38, 95% Confidence Interval (CI) 1.22-1.56] and incidence [RR 1.17, 95% CI 1.08-1.27]. The specific cancer sites with increased mortality risk included head and neck cancers, as well as stomach cancer. For cancer incidence, associations were observed with head and neck, oral, esophageal, stomach, and pancreatic cancers. Significant heterogeneity (I2 statistic 65% to 90%) was observed among most cancer outcomes.

CONCLUSION

Our study found significant associations between smokeless tobacco use and cancer incidence and mortality. Targeted policy interventions, such as stricter regulations on smokeless tobacco use, are recommended to reduce its consumption and mitigate the associated cancer risks.

Trends in smokeless tobacco use and attributable mortality and morbidity in the South-East Asia Region: implications for policy

OBJECTIVES

To describe the prevalence of smokeless tobacco (SLT) use and number of users by year, in addition to trends in mortality and attributable disease burden in countries of the WHO South-East Asia Region (SEAR), to inform policies for SLT control in the Region.

METHODS

For each SEAR country, we obtained data from Global Adult Tobacco Surveys, WHO STEPwise Approach to NCD Risk Factor Surveillance surveys and Demographic and Health Surveys conducted since 2010 to estimate prevalence of SLT use by country, sex and year. Using data from the World Population Prospects database we estimated the number of users by country. Next, using the results of previous meta-analyses and prevalence results, we estimated the population attributable fractions and attributable mortality and morbidity in terms of annual deaths and disability-adjusted life years lost. We then characterised trends in attributable deaths and disease burden for countries with comparable data.

RESULTS

There were wide differences in SLT use prevalence by country. We estimated that, during 2015-2019, there were 165 803 900 SLT users across SEAR, with 479 466 attributable deaths annually of which India accounted for 79.9% with 383 248. Attributable annual deaths increased in some countries during 2015-2019.

CONCLUSIONS

Annual deaths and disease burden attributable to SLT remain high across SEAR and have only declined modestly in recent years. Effective implementation of all WHO Framework Convention on Tobacco Control measures, addressing both supply-side and demand-side issues, in relation to SLT and areca nut products must be prioritised to ensure reductions in mortality and disease burden are sustained and accelerated.

Health effects associated with chewing tobacco: a Burden of Proof study

Chewing tobacco use poses serious health risks; yet it has not received as much attention as other tobacco-related products. This study synthesizes existing evidence regarding the health impacts of chewing tobacco while accounting for various sources of uncertainty. We conducted a systematic review and meta-analysis of chewing tobacco and seven health outcomes, drawing on 103 studies published from 1970 to 2023. We use a Burden of Proof meta-analysis to generate conservative risk estimates and find weak-to-moderate evidence that tobacco chewers have an increased risk of stroke, lip and oral cavity cancer, esophageal cancer, nasopharynx cancer, other pharynx cancer, and laryngeal cancer. We additionally find insufficient evidence of an association between chewing tobacco and ischemic heart disease. Our findings highlight a need for policy makers, researchers, and communities at risk to devote greater attention to chewing tobacco by both advancing tobacco control efforts and investing in strengthening the existing evidence base.

Death, Disability, and Premature Life Years Lost Due to Cigarettes, Bidis, and Smokeless Tobacco in India: A Comparative Assessment

BACKGROUND

Due to the staggering number of tobacco users in India, it is important to determine the exact mortality and morbidity rates due to tobacco use. This study aimed to estimate deaths, disability-adjusted life years (DALYs), and years of life lost (YLLs) attributable to cigarettes, bidis, and smokeless tobacco (SLT) in India.

METHODS

Data pooling and meta-analysis were done using case-control studies available on the three types of tobacco products. Health burden was estimated by applying the population attributable fraction (PAF) value to the total disease burden.

FINDINGS

A total of 33 studies were included. PAF was calculated for oral and lung cancer as well as ischemic heart disease (IHD) due to cigarettes, oral and lung cancer, IHD, and chronic obstructive pulmonary disease due to bidi, and oral and stomach cancer and IHD due to SLT. Cigarettes resulted in 8.4 million DALYs, 8.26 million YLLs, and 341 deaths; bidis led to 11.7 million DALYs, 10.7 million YLLs, and 478 thousand deaths, and SLTs accounted for 4.38 million DALYs, 4.3 million YLLs, and 171 thousand deaths annually.

CONCLUSION

Evidence of measurable health burden and methodology for calculation for individual states was provided in the study. The generated evidence could be utilized for policy recommendations and revision of the existing taxation norms.

Potential Risk Factors of Smokeless Tobacco Consumption Among Adolescents in South India

INTRODUCTION

Although most of the disease burden internationally is due to tobacco smoking, smokeless tobacco (SLT) use contributed to an estimated 76 000 deaths in 2017. We have studied the potential risk factors for SLT use among adolescents in South India.

METHODS

A cross-sectional questionnaire survey of all students in grades 6-8 in schools in the Udupi district of Karnataka State ascertained SLT use status and potential determinants of SLT uptake. Ever SLT use was defined as any reported consumption of any SLT products, currently or at any time in the past. Independent effects on ever SLT use status were estimated using multiple logistic regression.

RESULTS

Of 46 706 students from 914 participating schools, 39 282 (84.1%) provided questionnaire responses sufficiently complete for analysis. Ever SLT use was reported by 775 (2.0%) participants and in a mutually adjusted model was significantly related to age, male sex, family use, or friend's use of SLT, low socioeconomic status, high rebelliousness, and low self-esteem. After controlling for these effects, the odds of ever-SLT use were significantly higher among students who had least awareness of the harmful effects of tobacco use (odds ratio 3.7, 95% confidence interval [2.9, 4.7]) and significantly lower among those not exposed to tobacco advertising (odds ratio 0.7, 95% confidence interval [0.5, 0.8]).

CONCLUSIONS

The prevalence of SLT use among children in Karnataka is relatively low when compared with other studies in India. The significant potential risk factors of SLT use include low awareness of the harmful effects of tobacco and tobacco control policies and exposure to tobacco advertising.

IMPLICATIONS

The prevalence of SLT use among school going adolescents in South India is relatively low. The potential risk factors for SLT use among adolescents in southern India are similar to those for smoked tobacco. It includes age, male gender, family or friend's use of SLT, low socioeconomic status, high rebelliousness, low self-esteem, exposure to tobacco advertisement and least awareness about the harmful effects of tobacco and of tobacco control policies. The present study lays emphasis regarding creating awareness about tobacco harms and control policies for further reducing tobacco use among adolescents.

The health impact of smokeless tobacco products: a systematic review

INTRODUCTION

The objective was to systematically review studies on health outcomes from smokeless tobacco (SLT) products.

METHODS

We analysed published literature on the health outcomes from SLT use between 01/01/2015 to 01/02/2020, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol using PubMed, Embase, Scopus, and Google Scholar.

RESULTS

Of 53 studies included, six were global, 32 from Asia, Middle East and Africa (AMEA), nine from USA and six from Europe. 'Poor'-rated studies predominated (23;43%), in particular, for global (4;66%) and AMEA (16;50%). Health outcomes differed between SLT-products and regions; those in AMEA were associated with higher mortality (overall, cancer, Coronary heart disease (CHD), respiratory but not cardiovascular disease (CVD)), and morbidity (CVD, oral and head and neck cancers), with odds ratios up to 38.7. European studies showed no excess mortality (overall, CVD, from cancers) or morbidity (ischemic heart disease (IHD), stroke, oral, head and neck, pancreatic or colon cancers) from several meta-analyses; single studies reported elevated risk of rectal cancer and respiratory disorders. Pooled study data showed protection against developing Parkinson's disease. US studies showed mixed results for mortality (raised overall, CHD, cancer and smoking-related cancer mortality; no excess risk of respiratory or CVD mortality). Morbidity outcomes were also mixed, with some evidence of increased IHD, stroke and cancer risk (oral, head and neck). No studies reported on switching from cigarettes to SLT-products.

CONCLUSION

Our review demonstrates stark differences between different SLT-products in different regions, ranging from zero harm from European snus to greatly increased health risks in AMEA. The literature on the safety profile for SLT-products for harm reduction is incomplete and potentially misinforming policy and regulation.

Modeling mortality risk effects of cigarettes and smokeless tobacco: results from the National Health Interview Survey Linked Mortality File Data

BACKGROUND

Cigarettes and smokeless tobacco (SLT) products are among a wide range of tobacco products that are addictive and pose a significant health risk. In this study, we estimated smoking- and SLT use-related mortality hazard ratios (HRs) among U.S. adults by sex, age group, and cause of death, for nine mutually exclusive categories of smoking and/or SLT use.

METHODS

We used data from the public-use National Health Interview Survey Linked Mortality with mortality follow-up through 2015. We used Cox proportional hazard models to estimate mortality HRs, adjusted by race/ethnicity, education, poverty level, body mass index, and tobacco-use status.

RESULTS

With never users as reference group, HRs for smoking-related diseases for male exclusive current smokers aged 35-64 and 65+ were 2.18 (95% confidence interval [CI]: 1.79-2.65), and 2.45 (95% CI: 2.14-2.79), respectively. Similar significant HR estimates were found for females and for all-cause mortality (ACM) and other-cause mortality (OCM) outcomes. HRs for exclusive current SLT users were only significant for males aged 35-64 for ACM (HR: 2.04, 95% CI: 1.27-3.27) and OCM (HR: 2.80, 95% CI: 1.50-5.25). HRs for users who switched from cigarettes to SLT products were significant for males aged 65+ for smoking-related diseases (HR: 2.06, 95% CI: 1.47-2.88), SLT-related diseases (HR: 1.99, 95% CI: 1.36-2.89), and ACM (HR: 1.63, 95% CI: 1.21-2.19).

CONCLUSIONS

Male exclusive current SLT users aged 35-64 had a significant HR for ACM and OCM outcomes, suggesting that deaths not attributed to SLT use could be contributing to the ACM elevated HR for exclusive current SLT users.

Administration of N-acetylcysteine Plus Acetylsalicylic Acid Markedly Inhibits Nicotine Reinstatement Following Chronic Oral Nicotine Intake in Female Rats

Background

Nicotine is the major addictive component of cigarette smoke and the prime culprit of the failure to quit smoking. Common elements perpetuating the use of addictive drugs are (i) cues associated with the setting in which drug was used and (ii) relapse/reinstatement mediated by an increased glutamatergic tone (iii) associated with drug-induced neuroinflammation and oxidative stress.

Aims

The present study assessed the effect of the coadministration of the antioxidant N-acetylcysteine (NAC) plus the anti-inflammatory acetylsalicylic acid (ASA) on oral nicotine reinstatement intake following a post-deprivation re-access in female rats that had chronically and voluntarily consumed a nicotine solution orally. The nicotine-induced oxidative stress and neuroinflammation in the hippocampus and its effects on the glutamate transporters GLT-1 and XCT mRNA levels in prefrontal cortex were also analyzed.

Results

The oral coadministration of NAC (40 mg/kg/day) and ASA (15 mg/kg/day) inhibited by 85% of the oral nicotine reinstatement intake compared to control (vehicle), showing an additive effect of both drugs. Acetylsalicylic acid and N-acetylcysteine normalized hippocampal oxidative stress and blunted the hippocampal neuroinflammation observed upon oral nicotine reinstatement. Nicotine downregulated GLT-1 and xCT gene expression in the prefrontal cortex, an effect reversed by N-acetylcysteine, while acetylsalicylic acid reversed the nicotine-induced downregulation of GLT-1 gene expression. The inhibitory effect of N-acetylcysteine on chronic nicotine intake was blocked by the administration of sulfasalazine, an inhibitor of the xCT transporter.

Conclusion

Nicotine reinstatement, following post-deprivation of chronic oral nicotine intake, downregulates the mRNA levels of GLT-1 and xCT transporters, an effect reversed by the coadministration of N-acetylcysteine and acetylsalicylic acid, leading to a marked inhibition of nicotine intake. The combination of these drugs may constitute a valuable adjunct in the treatment of nicotine-dependent behaviors.

Association of smokeless tobacco and cerebrovascular accident: a systematic review and meta-analysis of global data

BACKGROUND

The association of smokeless tobacco (SLT) with stroke has been dealt with in only a few reviews. The present meta-analysis aims to present the updated comprehensive summary risk of stroke in adult SLT users along with sub group analysis.

METHODS

A systematic literature search for articles evaluating risk of stroke in SLT users was conducted. The study characteristics and risk estimates were extracted independently by two authors (RG and SG). Random-effect model was used to estimate the summary relative risks.

RESULTS

The overall risk of stroke in SLT users was found to be significantly higher (1.17, 95% CI 1.04–1.30) compared to non-users, especially for users in Southeast Asian region. The results remained unchanged even after strict adjustment for smoking (1.18, 95% CI 1.04–1.32). SLT users had 1.34 times or 13.4% higher risk of fatal stroke, though risk of nonfatal stroke was not enhanced. Significantly higher risk of stroke was seen in users of chewing tobacco (1.35, 95% CI 1.20–1.50) in comparison to non-chewers. Gender-based analysis showed enhanced risk of fatal stroke in both male and female users. SLT-attributable fraction of fatal stroke was highest for India at 14.8%.

CONCLUSION

The significant higher risk of stroke with SLT use, even after adjustment for smoking, emphasizes the imperative need to include SLT cessation advice for control and prevention of stroke.

Smokeless tobacco and public health in Bangladesh

Despite the high prevalence of smokeless tobacco (SLT) use among adults in Bangladesh, SLT was not included in the Tobacco Control Law till 2013. Information on SLT use among Bangladeshi people is inadequate for policymaking and implementing effective control measures. With the aim to identify the prevalence and trends of different SLT products, health and economic impacts, manufacture, and sale of and policies related to SLT in Bangladesh, we carried out a literature review, which involved literature search, data extraction, and synthesis. Evidence suggests that in Bangladesh, SLTs range from unprocessed to processed or manufactured products including Sada Pata, Zarda, Gul, and Khoinee. Over 27% of Bangladeshi adults aged 15 years and older use SLT in one form or other. SLT use is associated with age, sex, education, and socioeconomic status. SLT consumption has reportedly been associated with increased prevalence of heart diseases, stroke, and oral cancer and led to around 320,000 disability adjusted life years lost in Bangladesh in 2010. No cessation service is available for SLT users in public facilities. Compared to cigarettes, taxation on SLT remains low in Bangladesh. The amendment made in Tobacco Control Law in 2013 requires graphic health warnings to cover 50% of SLT packaging, ban on advertisement of SLT products, and restriction to sale to minors. However, implementation of the law is weak. As the use of SLT is culturally accepted in Bangladesh, culturally appropriate public awareness program is required to curb SLT use along with increased tax and cessation services.

The Determinants of Salivary Cotinine Concentration in Smokeless Tobacco Users

BACKGROUND

Smokeless tobacco products due to their high nicotine content are highly addictive and ultimately lead to an increased risk of oral cavity, laryngeal and oesophagal cancer.

AIM

This research was conducted with the aim of assessing the relationship between the salivary cotinine concentration and demographic characteristics and smokeless tobacco use for the first time in tradespeople in Chabahar, Iran.

METHODS

This descriptive cross-sectional study was conducted on 150 different tradespeople using smokeless tobacco in Chabahar who were selected through simple random sampling in 2018. In addition to the salivary cotinine measurement, data were collected using a researcher-made questionnaire with demographic and behavioural items. The data obtained were analysed in SPSS-16 using descriptive and inferential statistics.

RESULTS

The mean salivary cotinine score was 887.7 ± 180.7 in men and 611.2 ± 139.7 in women, making for a significant intergroup difference (P = 0.043). The mean salivary cotinine score was higher in those who used two or more smokeless tobacco products compared to those who used one type of tobacco, and a significant difference was observed between the type of smokeless tobacco used and the salivary cotinine score in the participants (P = 0.005).

CONCLUSION

Based on the results of the regression analysis, the type of smokeless tobacco used was a strong predictor of the concentration of salivary cotinine in the participants. It is, therefore, necessary for the government to adopt appropriate policies and take educational measures to reduce the vending and use of these substances.

Risk of Coronary Heart Disease Among Smokeless Tobacco Users: Results of Systematic Review and Meta-Analysis of Global Data

BACKGROUND

Use of smokeless tobacco (SLT) products has been linked to multiple adverse effects, especially precancer and cancer of oral cavity. However, the association of SLT use with risk of coronary heart disease (CHD) is shrouded with controversy due to conflicting results in the literature. The present meta-analysis aimed to evaluate the risk of CHD among adult ever-users of SLT products along with sub-group analysis.

METHODS

The analysis included studies retrieved from a systematic literature search for published articles assessing risk of CHD with SLT use. Two authors independently extracted risk estimates and study characteristics of the included studies. Summary relative risks were estimated using the random-effect model.

RESULTS

Twenty studies from four WHO regions were included in the analysis. The summary risk of CHD in SLT users was not significantly positive (1.05, 95% CI = 0.96 to 1.15) although a higher risk of fatal CHD was seen (1.10, 95% CI = 1.00 to 1.20). The risk was significant for users in European Region (1.30, 95% CI = 1.14 to 1.47). The results remained unchanged even after strict adjustment for smoking. Product-wise analysis revealed a significant positive association of fatal CHD with snus/snuff use (1.37, 95% CI = 1.14 to 1.61). The SLT-attributable fraction of fatal CHD was calculated to be 0.3%, highest being for European region (5%).

CONCLUSION

A significant positive association was detected between SLT use and risk of fatal CHD, especially for European users and those consuming snus/snuff. In view of the positive association even after strict adjustment for smoking, these results underscore the need for inclusion of cessation efforts for smokeless tobacco in addition to smoking for control of fatal cardiovascular diseases.

IMPLICATIONS

The present meta-analysis demonstrates a global perspective of association between coronary heart disease (CHD) and use of smokeless tobacco (SLT), especially for fatal cardiac events, even with strict adjustment for smoking. There appears to be some difference in this effect based on the type of SLT product used. These results highlight the independent deleterious effect of SLT products on the outcome of CHD and might help to resolve the long-standing controversy regarding the association of SLT with the risk of CHD. Hence, we propose that in addition to smoking, cessation efforts should be directed towards SLT products as well, for control of cardiovascular diseases.

Relationship between type of smokeless tobacco & risk of cancer: A systematic review

BACKGROUND & OBJECTIVES

Causative linkages of smokeless tobacco (SLT) use with oral potentially malignant disorders and cancers of oral cavity, oesophagus and pancreas have been reported. Published meta-analyses have provided pooled risk estimates for major cancers caused by SLT, both on global and regional levels. This systematic review was aimed at summarizing the available studies on occurrence and mortality risk of common cancers due to various SLT products.

METHODS

PubMed and Google Scholar databases were systematically searched from 1985 till January 2018 for observational studies on SLT and cancer. The included studies were evaluated and data were extracted and reviewed.

RESULTS

The review included 80 studies providing 121 risk estimates for various cancers. Majority of the studies from South-East Asian Region (SEAR) and Eastern Mediterranean Region (EMR) showed a significant positive association of SLT use with oral [odds ratio (OR) ranging from 1.48 to 27.4] and oesophageal cancers (OR between 2.06 and 12.8), while studies from European Region (EUR) reported a positive association with pancreatic cancer (OR between 1.6 and 2.1). Cancer-related mortality was evaluated in a few reports with higher risk of mortality for lung (OR between 2.0 and 9.1), cervical (OR 2.0) and prostate (OR 2.1) cancers. A wide variation was noted in the association of various cancers and specific SLT products based on their nature, methods of use and inherent toxicity. The majority of chewing tobacco products displayed higher risk for oral and oesophageal cancers while the same was not observed for snus.

INTERPRETATION & CONCLUSIONS

This review emphasizes on the significantly positive association of SLT use with oral and oesophageal cancers in SEAR and EMR and pancreatic cancer in EUR. Mortality estimates for SLT-associated cancers need further analysis. Risk analysis for cancers of other sites in SLT users also requires multicentric well-designed studies.

Implementation of Article 20 of the World Health Organization Framework Convention on Tobacco Control

BACKGROUND & OBJECTIVES

Article 20 of the World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) deals with surveillance and research on all tobacco products including smokeless tobacco (SLT). Here we describe the availability of indicators related to SLT among 180 Parties to the convention (countries ratifying the WHO FCTC are referred as Parties to the Convention).

METHODS

Data on SLT use among adults and adolescents and SLT-related economic and health indicators among Parties were obtained through rigorous literature search. Data analysis for high-burden parties was done using SPSS.

RESULTS

Nearly 92 per cent (166) of the Parties reported SLT use prevalence among adults or adolescents at national or subnational level, of these nearly one-fifth of the Parties (20.5%) were high-burden Parties. Comparable SLT tax incidence rate was available for 19.4 per cent (n=35) Parties, and SLT attributable morbidity and mortality risks of major diseases were available for only five per cent (n=10) of Parties.

INTERPRETATION & CONCLUSIONS

SLT use is a global epidemic widespread among Parties to the Convention. There are a data gap and dearth of research on SLT-related issues. Parties need to monitor SLT use and related health and economic indicators regularly at periodic intervals.

A systematic review on association between smokeless tobacco & cardiovascular diseases

BACKGROUND & OBJECTIVES

The association of smokeless tobacco (SLT) with cardiovascular diseases has remained controversial due to conflicting reports from various countries. Earlier meta-analyses have shown significantly higher risk of fatal myocardial infarction and stroke in SLT users. However, the risk of hypertension (HTN) with SLT products has not been reviewed earlier. This systematic review was undertaken to summarize the evidence available from global literature on the association of SLT with cardiovascular outcomes - heart disease, stroke and HTN.

METHODS

A systematic literature search was performed in PubMed and Google Scholar since their inception till October 2017 using pre-decided search terms and inclusion/exclusion criteria. Data were extracted from studies included independently by two authors and reviewed.

RESULTS

The review included 50 studies - 23 on heart disease, 14 on stroke and 14 on HTN. Majority of the studies evaluating heart disease or stroke were conducted in the European Region and most of these did not find a significant association between SLT use and either of these outcomes. On the other hand, 70 per cent of the studies on HTN were reported from South-East Asian Region and about half of the studies found a higher risk of HTN in SLT users.

INTERPRETATION & CONCLUSIONS

Current available evidence is insufficient to conclusively support the association of cardiovascular diseases with SLT use due to variability in results and methodological constraints in most of the studies. Region and product-specific well-designed studies are required to provide this evidence to the policymakers. However, advice on cessation of SLT products should be offered to patients presenting with cardiovascular diseases.

Comparison of Salivary Cotinine Concentrations in Male Smokers and Smokeless Tobacco Users

Objective: Smoking cigarettes and smokeless tobacco are one of the causes of oral cancer. This study compared the salivary level of cotinine in male smokeless tobacco users and smokers. Methods: In this cross-sectional (descriptive-analytical) study, stimulated saliva samples from 30 male smokers and 30 male smokeless tobacco consumers were collected and their cotinine contents were measured using the competitive ELISA method according the standard curve. The data was analyzed with independent t-test and linear regression using SPSS-19, and P<0.05 was considered significant. Result: Among the 60 subjects with the mean age of 21.27±2.6 years, the average level of cotinine in smokers (12.32±7.5 ng/ml) had no significant difference with that of smokeless tobacco consumers (11.23±4.4 ng/ml) (p=0.49). Conclusion: Salivary levels of cotinine were not significantly different in smokeless tobacco users and cigarette smokers. In addition, increases in the number of cigarettes smoked and in pack of smokeless tobacco used, were associated with increased salivary levels of cotinine. The increase was higher in smokeless tobacco consumers.

Killing two birds with one stone? Association between tobacco and alcohol consumption

OBJECTIVES

Tobacco and excessive alcohol consumption are addictive behaviours, listed among the 10 leading risk factors that cause death and disability in the world, and health consequences are greater if their consumption is combined. There is sparse empirical evidence on the variables that influence the simultaneous consumption of tobacco and alcohol. This study aims to identify the variables that influence the joint decision to consume alcohol and tobacco, and that encourage drinkers to smoke.

STUDY DESIGN

The sample includes Portuguese adults, mainly aged 50 years and over, extracted from the Survey of Health, Ageing and Retirement in Europe, covering the year 2011.

METHODS

We propose a bivariate probit model, which allows us to model simultaneously the two goods, accounting for potential correlation between smoking and drinking decisions.

RESULTS

We identified the variables that influence joint consumption, and tobacco consumption among drinkers, which could be used as policy instruments to develop concerted policies. Prevention policies should focus on males, younger and more educated individuals, as well as on individuals with unhealthy eating habits, because these variables were statistically significant and increased joint consumption. In addition, these characteristics also should be regarded if we want to control tobacco consumption among alcohol consumers.

CONCLUSIONS

The analysis of the interdependence between alcohol and tobacco use presented in this article may allow reducing their consumption with a common intervention, enabling policymakers to 'kill two birds with one stone' and to achieve extended health and economic gains.

Hazards of cigarettes, smokeless tobacco and waterpipe in a Middle Eastern Population: a Cohort Study of 50 000 individuals from Iran

BACKGROUND

There is limited information about the hazards of cigarettes, smokeless tobacco and waterpipe in the Middle East. The aim of this study was to determine the association between different types of tobacco use and earlier death in the Golestan Cohort Study.

METHODS

The Study includes 50 045 adults (aged 40-75 years) from north eastern Iran. The baseline questionnaire (2004-2008) assessed information about use of cigarettes, chewing tobacco (nass) and waterpipe. To assess the use of each type of tobacco compared with never tobacco users, we used Cox regression models adjusted for age, socioeconomic status, area of residence, education and other tobacco used, and stratified by sex, ethnicity and opium use.

RESULTS

17% of participants reported a history of cigarette smoking, 7.5% chewing tobacco (nass) and 1.1% smoking waterpipe, and these figures declined in the later birth cohorts. During a median follow-up of 8 years, 4524 deaths occurred (mean age 64.8+9.9 years). Current (HR=1.44; 95% CI 1.28 to 1.61) and former (HR=1.35; 95% CI 1.16 to 1.56) cigarette smokers had higher overall mortality relative to never tobacco users. The highest cigarette-associated risk was for cancer death among current heavy smokers (HR=2.32; 95% CI 1.66 to 3.24). Current nass chewing was associated with overall mortality (HR=1.16; 95% CI 1.01 to 1.34), and there was a 61% higher risk of cancer death in people chewing nass more than five times a day. We observed an association between the cumulative lifetime waterpipe use (waterpipe-years≥28) and both overall (HR=1.66; 95% CI 1.11 to 2.47), and cancer mortality (HR=2.82; 95% CI 1.30 to 6.11).

CONCLUSIONS

Regular use of cigarettes, smokeless tobacco and waterpipe were associated with the risk of earlier death (particularly from cancer) in our cohort.

Trends of Smokeless Tobacco use among Adults (Aged 15-49 Years) in Bangladesh, India and Nepal

BACKGROUND

Smokeless tobacco (SLT) has long been realized as an important component of the fight for global tobacco control. It still remains a major problem in countries like India, Bangladesh and Nepal. The objective of this study was to estimate the trends of SLT use in three countries of the SEARO WHO office.

MATERIALS AND METHODS

We used data from national surveys in three countries (Bangladesh, India and Nepal) to estimate trends in prevalence of current SLT use. All available nationally representative data sources were used. Estimates were weighted, age standardized and given along with 95% confidence intervals. Significance of linear trend in prevalence over time was tested using the Cochrane-Armitage test for trend. A p value of less than 0.05 was considered statistically significant.

RESULTS

We identified three surveys for Bangladesh, three for India and four for Nepal that met the selection criteria (such as Demographic and Health Surveys, WHO-STEPwise approach to Surveillance and Global Adult Tobacco Surveys). A significantly increasing trend was noticed in the prevalence of current SLT use among Bangladeshi men (20.2% to 23%, p=0.03). In India, a similar significantly increasing trend was seen among men (27.1% to 33.4%, p<0.001) and women (10.1% to 15.7%, p<0.001). In Nepal, there was a no significant trend among both men (39.1% to 31.6%, p=0.11) and women (5.6% to 4.7%, p=0.49).

CONCLUSIONS

In the study countries SLT use has remained at alarmingly high levels. Usage trends do not show any signs of decline in spite of control efforts. Tobacco control measures should focus more on controlling SLT use.

Molecular Links between Alcohol and Tobacco Induced DNA Damage, Gene Polymorphisms and Patho-physiological Consequences: A Systematic Review of Hepatic Carcinogenesis

Chronic alcohol and tobacco abuse plays a crucial role in the development of different liver associated disorders. Intake promotes the generation of reactive oxygen species within hepatic cells exposing their DNA to continuous oxidative stress which finally leads to DNA damage. However in response to such damage an entangled protective repair machinery comprising different repair proteins like ATM, ATR, H2AX, MRN complex becomes activated. Under abnormal conditions the excessive reactive oxygen species generation results in genetic predisposition of various genes (as ADH, ALDH, CYP2E1, GSTT1, GSTP1 and GSTM1) involved in xenobiotic metabolic pathways, associated with susceptibility to different liver related diseases such as fibrosis, cirrhosis and hepatocellular carcinoma. There is increasing evidence that the inflammatory process is inherently associated with many different cancer types, including hepatocellular carcinomas. The generated reactive oxygen species can also activate or repress epigenetic elements such as chromatin remodeling, non-coding RNAs (micro-RNAs), DNA (de) methylation and histone modification that affect gene expression, hence leading to various disorders. The present review provides comprehensive knowledge of different molecular mechanisms involved in gene polymorphism and their possible association with alcohol and tobacco consumption. The article also showcases the necessity of identifying novel diagnostic biomarkers for early cancer risk assessment among alcohol and tobacco users.