Smokeless tobacco, cardiovascular risk factors, and nicotine and cotinine levels in professional baseball players

Association of Cardiovascular Disease Risk Factors with Exclusive Smokeless Tobacco Use among US Males: Cross-Sectional Analysis of NHANES Data 2003-2018

PURPOSE

To evaluate cardiovascular disease (CVD) risk factors among smokeless tobacco (ST) users. Exclusive ST users were compared to exclusive cigarette smokers and non-tobacco users.

DESIGN

Cross-sectional study.

SAMPLE

Data were used from 16,336 adult males who participated in one of the National Health and Nutrition Examination Surveys (NHANES) from 2003 to 2018.

MEASURES

Biochemically verified tobacco use, CVD risk factors (hypertension, cholesterol levels, BMI categories), physical activity, cotinine concentration, and sociodemographic variables.

ANALYSIS

Weighted analysis of the aggregate data was performed. ST users were compared with cigarette smokers and nontobacco users for their association with CVD risk factors. Associations were examined using univariate and multiple logistic regression with odds ratios (OR) and 95% confidence intervals (CI) reported.

RESULTS

Prevalence of exclusive ST use was 4.4% whereas, exclusive smoking was 22.2%. Among ST users, 36.2% were hypertensive, 24.5% had high cholesterol levels, and most of them were overweight (31.1%) or obese (52.6%). ST users were more likely to have hypertension compared to smokers (aOR = 1.48, 95%CI: 1.12, 1.95) and nontobacco users (aOR = 1.41, 95%CI: 1.09, 1.83) adjusted for other covariates. ST users were twice more likely to be obese than nontobacco users (aOR = 2.18, 95%CI: 1.52, 3.11). ST users had significantly higher cotinine concentration than smokers.

CONCLUSION

Study findings indicate substantial association of ST use among males with hypertension and obesity which are independent risk factors of CVD.

Smokeless Tobacco Use and Prevalence of Cardiovascular Disease Among Males in the Population Assessment of Tobacco and Health (PATH) Study, Waves 1–4

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Oral smokeless tobacco (SLT) products are non-combusted forms of tobacco that can be dependence producing.

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SLT use may pose health risks to users such as cardiovascular disease (CVD) through various pathways including influencing hemodynamics, endothelial dysfunction, inflammation, insulin resistance, hyperlipidemia, and arrhythmogenesis.

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Past studies have suggested a small, elevated risk of CVD among SLT users compared to never tobacco users.

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This study advances the literature by exploring how the duration of regular SLT use relates to CVD prevalence.

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In this study of ≥ 40-year-old men only, we did not find a consistent dose–response trend for years of SLT use and prevalence of CVD.

The purpose of this period prevalence study is to compare the prevalence of cardiovascular disease (CVD) in current/former established smokeless tobacco (SLT) users (ever SLT users who have used the product fairly regularly) to those who were: 1) never established cigarette smokers and SLT users, and 2) current/former established exclusive cigarette smokers (have smoked at least a 100 or more cigarettes in lifetime) only, adjusting for known risk factors for CVD. Analyses included 4,703 men ≥ 40 years of age who participated in the Population Assessment of Tobacco and Health (PATH) Study, Waves: 1–4, conducted between 2013 and 2017. Current users were those using SLT products daily or on some days, whereas former users had not used SLT and/or cigarettes in the past 12 months. CVD prevalence was defined as a self-reported diagnosis of congestive heart failure, stroke, or myocardial infarction. Among current/former established SLT users, years of use defined exposure history, while pack-years defined exposure history for smokers. Adjusted odds ratios (AOR) and 95% confidence intervals (CI) were reported with trend tests to examine dose–response associations. Current/former established exclusive SLT users were not significantly more likely to have had any CVD compared to never established cigarette and SLT users (OR = 1.7 [0.8–3.7]), or current/former established exclusive cigarette smokers (OR = 0.9 [0.5–1.8]). Current/former established exclusive cigarette smokers were more likely to have had any CVD compared to those who were never established cigarette and SLT users (OR = 1.6 [1.1–2.3]).

A systematic review report on tobacco products and its health issues in India

India is the second country in tobacco production in the world. Smoking tobacco products included Hookah, Cohutta, Chillum, Chillum, ganja, Beedi, Mava, Cigarettes, and cigar etc. Various types of smokeless tobacco like betel quid, khaini, mishri, snuff, gutkha are used. Fifty percent of them are addicted to smokeless tobacco. Sixty eight smokeless tobacco products were available in 2010; most of them included the risk of cancer warning except for loose tobacco products. Women mostly prefer 8 out of 29 gutkha brands. Out of these 29 gutkha brands, 15 were loose tobacco packets. India is the second-largest tobacco consumer, comprises of 27.5 crore consumers which altogether greater than the population of Western Europe. From among these 27.5 crore consumers, 16.4 crore people are smokeless tobacco in takers, 6.9 crore people are exclusive smokers and 4.2 crore people are both tobacco in takers and exclusive smokers. If we take this data into consideration early mortality of 45 crore people is expected by 2050 worldwide. Female basically are prone to fewer cigarettes per day as compared to males. On the other hand, a cigarette that is consumed by females has lower nicotine content as compared to males. In developing countries, the female population has less prevalence of smoking because the level of employment is low, socio-cultural norms, and health and beauty concerns. According to the estimation by the South East Asia Region (SEAR) in the year 2000 basically from India, we encounter death of about 18% men and about 3% of women due to tobacco. Various policies have been set up to control the use of tobacco. So that threat to public health is reduced. Policies like tobacco control policy, pro-health policy are set up for this purpose. Talking about the effects on a longer-term usage of water pipe can add up to the risk of getting affected by cancers of lungs, mouth, bladders, atherosclerosis, cardiovascular and pulmonary diseases, tooth extraction, etc.

Systemic Toxicity of Smokeless Tobacco Products in Mice

Introduction

Smokeless tobacco products such as snuff and snus are used worldwide. However, little is known about the systemic and cardiovascular toxicity of smokeless tobacco exposure.

Methods

Biomarkers of endothelial activation and injury, immune functions, platelet activation and insulin resistance were measured in 8-week old male C57BL/6 mice exposed to commercial snuff, CRP-2 reference snuff, commercial snus, CRP-1 reference snus, and nicotine in drinking water (100 µg/mL) for 4, 12, and 24 weeks.

Results

Twenty-four weeks of exposure to smokeless tobacco products or nicotine significantly decreased the levels of circulating Flk+/Sca+ endothelial progenitor cells. Twelve and 24 weeks of exposure to all the smokeless tobacco products and nicotine significantly decreased the levels of circulating CD19+ B cells, CD4+ T cells, CD8+ T cells, and CD11b+ monocytes, whereas 4 weeks of exposure to Camel snus and Copenhagen snuff significantly depleted the levels of peripheral blood CD19+ B cells and CD11b+ monocytes. Twenty-four weeks of exposure to smokeless tobacco products or nicotine significantly decreased plasma IFNγ levels. However, plasma TNFα levels were significantly increased in mice exposed to Copenhagen snuff or nicotine for 24 weeks. This was accompanied by a five to sevenfold increase in the hepatic expression of TNFα. Neither smokeless products nor nicotine affected plasma lipoproteins, platelet activation, or systemic insulin sensitivity.

Conclusions

Chronic exposure to snuff and snus suppresses circulating levels of EPCs, endothelial microparticles and immune cells, but increases plasma TNF-α levels. These effects of smokeless tobacco products are attributable, at least in part, to nicotine.

Implications

Exposure to smokeless tobacco products results in the depletion of endothelial progenitor cells, which may impair the endothelium repair. Suppression of the circulating levels of immune cells upon exposure to smokeless tobacco products may increase the susceptibility to secondary infection. Increased formation of proinflammatory cytokines such as TNFα by nicotine or Copenhagen snuff may lead to vascular inflammation and thereby exacerbate atherogenesis.

Correlation of urinary cotinine with cardiovascular risk factors in pan masala tobacco users

BACKGROUND

Tobacco consumption is considered as one of the major risk factors for cardiovascular (CV) morbidity. However, the effect of paan masala tobacco (PMT) (a type of smokeless tobacco) consumption has not been well studied in our context. Our study is aimed to find an association of CV risk factors between PMT users and nonusers and to correlate those parameters with urinary cotinine level, a degradation product of nicotine occurring in tobacco.

METHODS

This comparative cross-sectional study was carried out among 200 participants. The effect of PMT use on CV risk factors such as blood pressure (BP), lipid profile, and body mass index was measured against urine cotinine level. Statistical tests used were χ2 test for categorical variable, independent t-test, Mann-Whitney U test, and Spearman's correlation applied for numerical variable, and multivariate regression analysis was performed as required. The level of significance was set at p < 0.05.

RESULT

Mean BP, total cholesterol, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and median cotinine level were found to be significantly higher in PMT users than in controls (p < 0.001). Urinary cotinine level was positively correlated with mean BP, TC, TG, and LDL-C in PMT users (p < 0.001). Similarly, the odds of having hypercholesterolemia and increased diastolic BP was also significantly higher in PMT users (p < 0.001).

CONCLUSION

PMT use has an adverse effect on CV risk parameters and there is a rational of cotinine measurement for screening CV risk among PMT users.

Smokeless tobacco: Risk factor for cardiovascular and breathing in young Indian adolescent

BACKGROUND

Teenagers are the foremost susceptible population to smokeless tobacco usage and limited studies have surveyed the influence of smokeless tobacco on cardiac and respiratory response.

OBJECTIVE

This study aims to measure consequence (cardiovascular and breathing) of smokeless tobacco usage (gutkha and chewing tobacco) among young Indian men.

METHOD

On random basis, the applicants were divided into Group I (n=50) - healthy control group, Group II (n=50) - smokeless tobacco users. Anthropometric measurements and recording of blood pressure (BP), pulse wave analysis (PWV), heart rate variability (HRV) and pulmonary function test (PFT) was performed.

RESULT

We observed that altogether anthropometric variables were comparable among all individuals. In blood pressure variable, except DBP, other variables for example SBP, PP and MAP were significantly increased in Group II individuals, once compare to Group I. Pulse wave analysis, (such as, AP, AIx, and SEVR), was comparable in individuals of both groups. As compare to Group I, HR was significantly increased in Group II. In HRV investigation, NN, VLF, LF, LF(nu), LF/HF were increased significantly and TSP, HF, HF(nu) were decreased significantly in Group II with compare to Group I. In PFT analysis, FVC was comparable among individuals of both the group and conversely, significant decrease in FEV₁, FEV₁/FVC, FEF_25-75 and PEFR in Group II when compare with Group I.

CONCLUSION

This study illustrate that smokeless tobacco practice has increasing adverse effects on cardiovascular as well as breathing system and become an important public health problem.

Predictors of Hypertension among Nonpregnant Females Attending Health Promotion Clinic with Special Emphasis on Smokeless Tobacco: A Cross-Sectional Study

Aim

To determine the predictors of hypertension among nonpregnant females attending a health promotion clinic.

Design and Setting

A cross-sectional study was conducted during March to June 2016, at the National Institute of Cancer Prevention and Research, India.

Methods

The study included 319 nonpregnant females of age 20–70 years. Demographics such as age, literacy, and income were noted. History regarding use, frequency, and quantity of smokeless tobacco was taken. Height, weight, and blood pressure were measured and body mass index was calculated.

Statistical Analysis

Pearson's product-moment correlation coefficient was calculated between each of the variables of age, smokeless tobacco consumption, and body mass index versus systolic and diastolic blood pressure, respectively. The linear as well as multiple linear regression analysis was employed to identify the risk factors for hypertension.

Results

A univariate linear regression analysis showed that age, smokeless tobacco consumption, and body mass index were associated with systolic blood pressure (P value < 0.001 for each). For diastolic blood pressure, high body mass index was a predictor. Multiple linear regression analysis showed that both systolic and diastolic hypertension were associated with high body mass index and low level of education. Moreover, the systolic hypertension was associated with higher age and smokeless tobacco use.

Conclusion

Health promotion requires control of body mass index and smokeless tobacco cessation for preventing hypertension and its complications.

Regular moist snuff dipping does not affect endurance exercise performance

Physiological and medical effects of snuff have previously been obtained either in cross-sectional studies or after snuff administration to non-tobacco users. The effects of snuff cessation after several years of daily use are unknown. 24 participants with >2 years of daily snuff-use were tested before and after >6 weeks snuff cessation (SCG). A control group (CO) of 11 snuff users kept their normal habits. Resting heart rate (HR) and blood pressure (BP) were significantly lower in SCG after snuff cessation, and body mass was increased by 1.4 ± 1.7 kg. Total cholesterol increased from 4.12 ± 0.54 (95% CI 3.89–4.35) to 4.46 ± 0.70 (95% CI 4.16–4.75) mM L^–1 in SCG, due to increased LDL, and this change was significantly different from CO. Resting values of HDL, C-reactive protein, and free fatty acids (FFA) remained unchanged in both groups. In SCG group, both HR and BP were reduced during a four-stage incremental cycling test (from 50 to 80% of VO₂max) and a prolonged cycling test (60 min at 50% of VO₂max). Oxygen uptake (VO₂), respiratory exchange ratio, blood lactate (bLa) and blood glucose (bGlu) concentration, and rate of perceived exertion (RPE) were unchanged. In CO group, all measurements were unchanged. During the prolonged cycling test, FFA was reduced, but with no significant difference between groups. During the maximal treadmill running test peak values of VO₂, pulmonary ventilation (V_E), time to exhaustion and bLa were unchanged in both groups.

In conclusion, endurance exercise performance (VO₂max and maximal endurance time) does not seem to be affected by prolonged snuff use, while effects on cardiovascular risk factors are contradictory. HR and BP during rest and submaximal exercise are reduced after cessation of regular use of snuff. Evidently, the long-time adrenergic stress on circulation is reversible.

Is smokeless tobacco a risk factor for coronary heart disease? A systematic review of epidemiological studies

BACKGROUND

There is on-going debate about the wisdom of substituting smokeless tobacco products for cigarette smoking as a 'harm reduction' strategy. It is generally believed that health risks associated with smokeless tobacco use (ST) are lower than those with cigarette smoking. However, the population attributable risk of smoking is higher for cardiovascular diseases than for any cancers, and few studies or reviews have considered the cardiovascular outcomes of ST use. A systematic review was therefore carried out to highlight the gaps in the evidence base.

METHODS

Electronic databases were searched, supplemented by screening reference lists, smoking-related websites, and contacting experts. Analytical observational studies of ST use (cohorts, case-control, cross-sectional studies) were included if they reported on cardiovascular disease (CVD) outcomes, or risk factors. Data extraction covered control of confounding, selection of cases and controls, sample size, clear definitions and measurements of the health outcome and ST use. One or two independent reviewers carried out selection, extraction and quality assessments.

RESULTS

A narrative review was carried out. Very few studies were identified; only three from Sweden consider CVD outcomes and these are discrepant. There may be a modest association between use of Swedish snuff (snus) and cardiovascular disease (e.g., relative risk=1.4, 95% confidence interval 1.2-1.6) in one prospective cohort study. Several other studies have considered associations between ST use and intermediate outcomes (CVD risk factors).

CONCLUSIONS

There may be an association between ST use and cardiovascular disease. However, further rigorous studies with adequate sample sizes are required.

Non-Smoking Tobacco Affects Endothelial Function in Healthy Men in One of the Largest Health Studies Ever Performed; The Nord-Trøndelag Health Study in Norway; HUNT3

BACKGROUND

Oral tobacco (snuff) is taking a large market share in Scandinavia, especially with young users. However, long-term health effects are unknown. Small studies show association between snuff and reduced endothelial function, representing an early stage of vascular injury that often precedes manifest cardiovascular disease by several years. We therefore determined the associations between snuff and endothelial function in a large sample of healthy Norwegian men.

METHODS AND DESIGN

In the Fitness substudy of the Nord-Trøndelag Health Study (HUNT3), endothelial function was measured by flow-mediated dilation (FMD). Aerobic fitness was measured by peak oxygen uptake (VO2peak). A cross-sectional design including 1 592 self-reported healthy men compared these observations with records of present tobacco use, standard cardiovascular risk factors, and socioeconomic status, using general linear models.

RESULTS

FMD was lower in snuff users (FMD: 4.12%, 3.63, 4.61) compared to non-users (FMD: 4.52%, 4.27, 4.78) after adjustment for age (difference: -0.57%, -1.12, -0.01). After further adjustment for potential confounders, FMD still tended to be lower in snuff users than in non-users (difference: -0.53%, -1.09, 0.02). This difference was even more pronounced in the inactive snuff users (-0.83%, -1.59, -0.06) and in the low fit snuff users (-0.74%, CI -0.55, 0.079).

CONCLUSIONS

Oral tobacco is associated with a tendency towards reduced endothelial function, indicating vascular changes that precede cardiovascular disease. The strongest associations were found in men with low physical activity or reduced aerobic fitness.

Study of cardiovascular disease biomarkers among tobacco consumers. Part 3: evaluation and comparison with the US National Health and Nutrition Examination Survey

Cardiovascular disease (CVD) biomarkers of biological effect (BoBE), including hematologic biomarkers, serum lipid-related biomarkers, other serum BoBE, and one physiological biomarker, were evaluated in adult cigarette smokers (SMK), smokeless tobacco consumers (STC), and non-consumers of tobacco (NTC). Data from adult males and females in the US National Health and Nutrition Examination Survey and a single site, cross-sectional study of healthy US males were analyzed and compared. Within normal clinical reference ranges, statistically significant differences were observed consistently for fibrinogen, C-reactive protein (CRP), hematocrit, mean cell volume, mean cell hemoglobin, hemoglobin, white blood cells, monocytes, lymphocytes, and neutrophils in comparisons between SMK and NTC; for CRP, white blood cells, monocytes, and lymphocytes in comparisons between SMK and STC; and for folate in comparisons with STC and NTC. Results provide evidence for differences in CVD BoBE associated with the use of different tobacco products, and provide evidence of a risk continuum among tobacco products and support for the concept of tobacco harm reduction.

Study of cardiovascular disease biomarkers among tobacco consumers, part 2: biomarkers of biological effect

An age-stratified, cross-sectional study was conducted in the US among healthy adult male cigarette smokers, moist snuff consumers, and non-tobacco consumers to evaluate cardiovascular biomarkers of biological effect (BoBE). Physiological assessments included flow-mediated dilation, ankle-brachial index, carotid intima-media thickness and expired carbon monoxide. Approximately one-half of the measured serum BoBE showed statistically significant differences; IL-12(p70), sICAM-1 and IL-8 were the BoBE that best differentiated among the three groups. A significant difference in ABI was observed between the cigarette smokers and non-tobacco consumer groups. Significant group and age effect differences in select biomarkers were identified.

Population attributable risk estimates for risk factors associated with hypertension in an Indian population

BACKGROUND

Little evidence exists regarding the magnitude of contribution of risk factors associated with hypertension in India. Determination of potentially modifiable risk factors is necessary to focus prevention strategies.

DESIGN

Age-matched case-control study.

METHODS

A total of 350 hypertensive cases and 350 controls of both sexes in the age group 20-65 years. Hypertension was defined according to JNC VII criteria. Adjusted odds ratio (OR) and population attributable risk percentage (PAR %) for hypertension were calculated.

RESULTS

In multivariate analysis, tobacco users (either tobacco chewing/smoking or both) (adjusted OR 5.1, 95% CI 3.6-7.3), tobacco chewing (adjusted OR 3.2, 95% CI 2.2-4.6), smoking (adjusted OR 2.9, 95% CI 1.9-4.4), and alcohol consumption (adjusted OR 1.5, 95% CI 1.1-2.2) was the strongest determinants of hypertension. A dose-response relation was found between the number of cigarettes smoked per day (χ2 for trend = 26.07; p < 0.0001) and the amount of alcohol consumption per day (χ2 for trend = 24.26; p < 0.0001) and the risk of hypertension. PARs were 70.3% (95% CI 63.0-77.5) for tobacco use, 45.3% (95% CI 37.1-53.4) for tobacco chewing, 31.5% (95% CI 21.3-40.9) for smoking, and 33.6% (95% CI 22.9-44.4) for alcohol consumption.

CONCLUSION

Our results indicate that incident hypertension cases are largely attributable to the habit of tobacco use and alcohol consumption. Therefore, changing these selected lifestyle factors needs to be prioritized as a major strategy for reducing incidence of hypertension in our population.

Smokeless tobacco and cardiovascular disease in low and middle income countries

Smoking is an important cardiovascular risk factor, however, use of smokeless tobacco has not been well studied. Smokeless tobacco use is high in countries of South and Southeast Asia, Africa and Northern Europe. Meta-analyses of prospective studies of smokeless tobacco users in Europe reported a relative risk for fatal coronary heart disease of 1.13 (confidence intervals 1.06-1.21) and fatal stroke of 1.40 (1.28-1.54) while in Asian countries it was 1.26 (1.12-1.40). Case-control studies reported significantly greater risk for acute coronary events in smokeless tobacco users (odds ratio 2.23, 1.41-3.52), which was lower than smokers (2.89, 2.11-3.96), and subjects who both chewed and smoked, had the greatest risk (4.09, 2.98-5.61). There is a greater prevalence of hypertension and metabolic syndrome in users of smokeless tobacco. Smokeless tobacco use leads to accelerated atherothrombosis similar to smoking. There is an urgent need for public health and clinical interventions to reduce smokeless tobacco addiction.

Social inequalities, tobacco chewing, and cancer mortality in south India: a case-control analysis of 2,580 cancer deaths among non-smoking non-drinkers

OBJECTIVE

The objective of this work was to describe the relationships between educational level, tobacco chewing, and cancer mortality in south India, among middle-aged adults who never smoked tobacco or drank alcohol, to eliminate confounding by those habits.

METHODS

This case-control study was conducted in two areas of Tamil Nadu state. The cases studied were 2,580 lifelong non-smoking non-drinkers who died at age 35-69 years during 1995-1998, with interviews in 1998-2000 of a spouse, neighbour, or close associate, who retrospectively provided information on the education and chewing/other habits of the deceased. Underlying neoplastic cause of death was determined by verbal autopsy. The controls were 429,306 lifelong non-smoking non-drinkers aged 35-69 from these two study areas, interviewed during 1998-2001.

RESULTS

Among the controls, prevalence of current tobacco chewing was much higher in those with less education, irrespective of sex, urban/rural residence, or birth year. Compared with never chewers, ever chewers had fivefold higher mortality from mouth cancer (odds ratio 4.9, 95% confidence interval 3.5-6.8), and 1.5 to twofold higher mortality from cancers of the pharynx/larynx/oesophagus combined, stomach, and cervix. Each of these cancers had a strong, independent, inverse association with educational level.

CONCLUSION

This study supports a substantial body of evidence that tobacco chewing can cause mouth cancer, and adds to evidence that chewing may increase the risk of cancer at other sites. The analysis suggests a possible link with cervical cancer, but this could have been because of residual confounding by social factors. Avoidance of tobacco chewing would avert many cancer deaths in south India, especially for people who have received relatively little formal education.

Effects of smokeless tobacco "Maras powder" use on nitric oxide and cardiovascular risk parameters

BACKGROUND

Smokeless tobacco use is common in various parts of the world. In Turkey a type of smokeless tobacco called "Maras powder" is widely used in southeastern region. Smoking is known to have an adverse effect on nitric oxide and cardiovascular risk factors. The aim of this study was to evaluate whether there is difference between the effects of Maras powder and cigarette smoking on the cardiovascular risk factors and nitric oxide levels.

METHODS

In the study, participants were 48 Maras powder users, 50 cigarette smokers and 45 nontobacco user subjects. Blood samples were collected and hematological parameters and lipid parameters were measured. Plasma Nitric oxide level was also detected by using the Griess method.

RESULTS

Plasma total cholesterol, LDL-cholesterol, triglyceride levels were significantly higher in Maras powder and cigarette smokers group than in the nontobacco user group (p<0.001). Plasma HDL-cholesterol levels were significantly lower in Maras powder and cigarette smokers group than in the nontobacco user group (p<0.001). Plasma Nitric oxide levels were found significantly lower in Maras powder and cigarette smokers group compared to the nontobacco user group (4.9±0.9 µmol/l, 4.8±1 µmol/l, 9.4±3.4 µmol/l, respectively, p<0.001) whereas there was no significant difference between the Maras powder and cigarette smokers group. In multivariate logistic regression model, cigarette smoking (Odds ratio=17.832, p<0.001), Maras powder usage (Odds ratio=12.311, p=0.002) and mean platelet volume (Odds ratio=1.425, p=0.030) remained independently associated with lower Nitric oxide levels.

CONCLUSION

We conclude that Maras powder has similar adverse effects on nitric oxide level and cardiovascular risk parameters and thereby it appears to be harmful as cigarette smoking.

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.

Association of exclusive smokeless tobacco consumption with hypertension in an adult male rural population of India

Introduction

Tobacco consumption is a major source of mortality and morbidity in India . Prevalence of smokeless tobacco (ST) consumption in India is around 20%. Studies have shown increased prevalence of cardiovascular disease risk factors and an increased incidence of adverse cardiovascular events among the ST consumers. This is a cross-sectional study done to look into the association of exclusive smokeless tobacco consumption with hypertension, in an adult male rural population of north India.

Methods

All male residents of a village in north India above 15 years of age, who did not have any acute or chronic morbidity were included after taking an informed consent. Subjects were interviewed regarding their demographic profile, socioeconomic status and tobacco consuming habits. Current smokeless tobacco user was defined as one who has ever consumed tobacco orally in past 1 month. Blood pressure of the subjects was also recorded. Cut offs used for systolic and diastolic hypertension were 140 mm hg and 90 mm Hg respectively.

Results

443 subjects were included in the study. Prevalence of exclusive ST users was 21% while 19.4% consumed both forms and 26.6% did not take any form of tobacco. Mean systolic and diastolic BP were significantly higher in exclusive ST users(systolic BP=139.2+17.4,diastolic BP = 86.8+11.5)as compared to the non users(systolic BP= 135.7+18.8 , diastolic BP= 82.6 +11.5; p value < 0.05). The prevalence of diastolic hypertension was significantly higher in exclusive ST users as compared to non users ( 40.9%, 22.9% ;p value = 0.01) . The OR for diastolic hypertension in male ST users was 2.3( 95% C.I. = 1.3-4.3). Prevalence of systolic hypertension was higher in exclusive ST users too though this was not statistically significant (43%,36.4%;p value = 0.39.).

Conclusion

ST consumption is associated with increased prevalence of high BP in the adult male rural population.This is an indicator of increased predisposition to major adverse cardiac events later in their life time. Prevention of ST consumption could be an important intervention in preventing the ongoing upswing in prevalence of chronic heart disease.

Risk of hypertension amongst Swedish male snuff users: a prospective study

BACKGROUND

The scientific evidence on whether long-term use of snuff is associated with high blood pressure is limited, inconsistent and based only on cross-sectional data.

OBJECTIVE

We aimed at studying the risk of hypertension in relation to long-term use of snuff based on longitudinal data.

DESIGN

Repeated health check-ups were offered to all employees in the Swedish construction industry between 1978 and 1993. Blood pressure was measured at the health check-up and information on tobacco use and other risk factors was collected through questionnaires.

SETTING

In total, 120 930 never smoking men with information on blood pressure and snuff use at baseline were included. The association of high blood pressure and snuff use at baseline was estimated by logistic regression. Further, 42 055 men were identified as normotensive at baseline and had at least one subsequent health check-up. Through repeated blood pressure measurements and linkage to the Swedish National Inpatient Register, information on hypertension was obtained. Relative risk estimates were derived from Cox proportional hazards regression model.

RESULTS

Almost 30% of all men had used snuff. The adjusted odds ratio of high blood pressure amongst snuff users at baseline was 1.23 (95% CI 1.15-1.33) compared to never snuff users. The relative risk of high blood pressure during follow-up was 1.39 (95% CI 1.08-1.79) amongst snuff users and 1.36 (95% CI 1.07-1.72) for hypertension as recorded in the Inpatient Register.

CONCLUSION

Use of Swedish moist snuff appears to be associated with a moderately increased risk of hypertension.

Factors associated with smokeless tobacco cessation in an Appalachian population

Identifying factors associated with successful tobacco quit attempts may help in the development and targeting of effective cessation strategies. This paper aims to describe factors associated with smokeless tobacco (ST) cessation and compares the results to findings in the smoking cessation literature. Prospective data on 116 men aged 19 to 70 and participating in a ST cessation program were used to examine correlates of successful ST cessation at 1-year post-intervention. Controlling for age, level of education (p=0.002) and daily coffee consumption (p=0.005) had significant independent associations with successful cessation. No ST use variables were significant predictors of cessation success. In a multivariable logistic regression model three factors were significantly associated with cessation: education (p=0.010), coffee consumption (p=0.019), and age (p=0.029). Factors associated with successful ST cessation in this sample are consistent with predictors of smoking cessation reported in the literature. Based on its widespread use and the strength of its association with successful quitting, the role of caffeine consumption in ST cessation merits further study.

Long-term use of Swedish moist snuff and the risk of myocardial infarction amongst men

BACKGROUND

The scientific evidence on cardiovascular risks associated with long-term use of snuff is limited and inconclusive. The use of this smokeless tobacco has increased in recent decades, and adverse health effects associated with snuff use could be of great public health concern.

OBJECTIVE

We aimed to study whether long-term use of snuff affects the risk of myocardial infarction.

DESIGN

Between 1978 and 1993 all construction workers in Sweden were offered repeated health check-ups by the Swedish Construction Industry's Organization for Working Environment Safety and Health. A cohort was created with information on tobacco use and other risk factors, collected through questionnaires.

SETTING

In total, 118,395 nonsmoking men without a history of myocardial infarction were followed through 2004. Information on myocardial infarction morbidity and mortality was obtained from national registers. Relative risk estimates were derived from Cox proportional hazards regression model, with adjustment for age, body mass index and region of residence.

RESULTS

Almost 30% of the men had used snuff. In total, 118 395 nonsmoking men without a history of myocardial infarction were followed through 2004. The multivariable-adjusted relative risks for ever snuff users were 0.91 (95% confidence interval, 0.81-1.02) for nonfatal cases and 1.28 (95% confidence interval, 1.06-1.55) for fatal cases. Heavy users (>or=50 g day(-1)) had a relative risk of fatal myocardial infarction of 1.96 (95% confidence interval, 1.08-3.58). Snuff use increased the probability of mortality from cardiovascular disease amongst nonfatal myocardial infarction patients.

CONCLUSION

Our results indicate that snuff use is associated with an increased risk of fatal myocardial infarction.

Circulatory disease and smokeless tobacco in Western populations: a review of the evidence

BACKGROUND

Use of oral snuff or 'snus' has risen in Sweden. Sales of snuff in the US have also risen, overtaking sales of chewing tobacco. There is some evidence that nicotine contributes to circulatory disease (CID) from smoking. We therefore reviewed the evidence relating smokeless tobacco (ST) to CID and related risk factors.

METHODS

Publications that described relevant cohort, case-control and cross-sectional studies were identified from in-house files, a Medline search in December 2005 and reference lists. Relative risks (RRs) and odds ratios (ORs) for ischaemic heart disease, stroke and all CID for ST use, stratified by smoking habit, were estimated and combined by meta-analysis to provide an overall RR estimate. For diabetes, increased blood pressure, and other risk factors, evidence was qualitatively reviewed, with results from clinical studies also considered.

RESULTS

ST use in non-smokers was associated with an increased risk of heart disease (RR 1.12, 95% CI 0.99-1.27, n = 8), stroke (1.42, 1.29-1.57, n = 5) and CID (1.25, 1.14-1.37, n = 3). The increases mainly derived from two large US studies. The Swedish studies provided little evidence of an increase for heart disease (1.06, 0.83-1.37, n = 5) or stroke (1.17, 0.80-1.70, n = 2), although the estimates by country are not notably heterogeneous, even for stroke (P = 0.29). No dose-response was evident. No increase was seen in former users of ST, or in ST users who also smoked. No clear relationship to diabetes was seen. In the US, an acute blood pressure rise following ST use was consistently reported, and isolated reports linked specific risk factors to ST. In Sweden, though one study reported that snuff acutely increased blood pressure, and two linked snuff to Raynaud-type symptoms, the overall evidence for an effect was inconclusive. Swedish studies generally showed no chronic effect of snuff on blood pressure or various risk factors.

CONCLUSIONS

Any CID risk from ST appears to be substantially less than from smoking, and no clear risk from Swedish snuff is seen. However, the overall evidence is limited.

Swedish moist snuff and myocardial infarction among men

BACKGROUND

Previous studies have provided inconsistent results on possible increased risk of cardiovascular disease with the use of smokeless tobacco. The aim of this study was to assess whether long-term use of Swedish moist snuff (widely used among Swedish men) increases the risk of acute myocardial infarction.

METHODS

This case-control study was conducted in 2 Swedish counties. We identified 1760 men, age 45-70 years, who had a myocardial infarction in 1992-1994. We randomly selected male controls from the study base after stratification for age and hospital catchment area. Information about snuff consumption, smoking history, hypertension, and other factors was obtained by mailed questionnaire and medical examination. The participation rate was 77% among cases and 78% among controls, with tobacco use data available for 1432 cases and 1810 controls.

RESULTS

After adjustment for age, hospital catchment area, and smoking, the relative risk of first acute myocardial infarction was 1.1 (95% confidence interval=0.8-1.5) for former snuff users and 1.0 (0.8-1.3) for current snuff users. Analyses limited to either nonfatal or fatal cases did not change the results. Among the controls, the consumption of smokeless tobacco was strongly associated with certain risk factors for myocardial infarction such as smoking, hypertension, and high body mass index.

CONCLUSION

The hypothesis that smokeless tobacco increases the risk for myocardial infarction is not supported in the present study.

Smokeless tobacco as a possible risk factor for stroke in men: a nested case-control study

BACKGROUND AND PURPOSE

Snuff and other forms of smokeless tobacco are widely used in some populations. Whereas the detrimental cardiovascular effects of smoking are well documented, possible health hazards associated with the use of smokeless tobacco remain controversial. The purpose of this study was to explore whether the use of snuff, a smokeless tobacco product, increases the risk of stroke in men.

METHODS

In a nested case-control study (1 case and 2 matched controls without cardiovascular disease), information on tobacco habits was collected through population risk factor surveys. During follow-up, first-ever fatal and nonfatal strokes occurring among 25- to 74-year-old participants were identified in a population-based stroke register. The study was restricted to men (276 cases, 551 controls).

RESULTS

The unadjusted odds ratio for stroke in regular cigarette smokers compared with men who never used tobacco was 2.21 (95% CI, 1.29 to 3.79). When never-smoking regular snuff dippers (excluding ex-smokers) were compared with men who never used tobacco, the unadjusted odds ratio was 1.05 (95% CI, 0.37 to 2.94). The odds ratio for never-snuffing smokers versus never-smoking snuff users was 2.90 (95% CI, 0.92 to 9.1). After adjustment for multiple cardiovascular risk factors, the odds ratio for having a stroke was 1.74 (95% CI, 0.85 to 3.54) in regular smokers and 0.87 (95% CI, 0.41 to 1.83) in regular snuff users.

CONCLUSIONS

Whereas regular smoking doubles the risk of stroke in men, snuff use is not associated with any apparent excess risk. Chemical moieties produced by burning tobacco are probably the most important contributors to smokers' excess risk of atherothrombotic disease, including stroke.

Spit (Smokeless)-Tobacco Use by Baseball Players Entering the Professional Ranks

OBJECTIVE: To describe the prevalence and characteristics of spit (smokeless)-tobacco (ST) use in rookie baseball players as they enter the professional ranks and to identify factors associated with use before entering professional baseball. DESIGN AND SETTING: This cross-sectional study was an anonymous questionnaire survey administered during the 1999 baseball season by professional baseball athletic trainers at 30 professional baseball clubs. SUBJECTS: The target group was all rookie professional baseball players entering professional baseball. Of 862 eligible players in the summer of 1999, 616 participated in the survey. MEASUREMENTS: The questionnaire assessed tobacco use, demographic variables relevant to rookie professional baseball players, and factors hypothesized to be associated with current ST use (ie, other forms of tobacco use, social norms, environmental cues, and risky behavior intentions). Univariate associations with ST use were described by relative risks with 95% confidence intervals. For continuous variables, mean values of ST users and nonusers were compared. RESULTS: Overall, 67% of the players had tried ST and 31% were current users. Significant risk factors for ST use were being a current cigarette or cigar smoker, having a family member who used ST, and perceiving ST use by peers and role models. CONCLUSIONS: Almost one third of rookie baseball players in the 1999 season were regular ST users on entering professional baseball. Interventions for prevention and cessation of the use of ST targeting young baseball players are needed.

In vitro effect of nicotine and cotinine on the susceptibility of LDL oxidation and hemoglobin glycosylation

Nicotine, a major component of cigarette smoke, plays an important role in the development of cardiovascular disease and lung cancer in smokers. This study was designed to determine the in vitro effects of nicotine and its metabolite cotinine on the susceptibility of LDL to oxidation and hemoglobin glycosylation. Three different concentrations of each one (10, 15, 25 microg/ml) were used. Our data show that nicotine and cotinine are inhibitors for Cu(2+)-induced LDL oxidation but also they increase the glycosylation degree of hemoglobin. Nicotine at final concentrations of (10, 15, 25 microg/ml) increases the rate of hemoglobin glycosylation 25, 32 and 47%, respectively, and cotinine at final concentrations increase the rate of glycosylation 8, 10 and 12%, respectively. Therefore promoting hemoglobin glycosylation is one of the alternations caused by smoking that increase risk of cardiovascular disease.

Smokeless tobacco and cardiovascular disease

Various forms of smokeless tobacco (mainly snuff and chewing tobacco) cause an immediate increase in heart rate and blood pressure, but regular users of smokeless tobacco do not have permanent changes of heart rate or blood pressure when not exposed to tobacco. Cardiac output during workload and maximal working capacity are unaffected. Users of smokeless tobacco usually do not have the biochemical stigmata that regular smokers have. Thus, the scientific literature suggests that they are similar to non-tobacco users in terms of levels of hemoglobin/hematocrit, leukocytes, antioxidant vitamins, fibrinogen, components of the fibrinolytic system, C-reactive protein, and thromboxane A2 production. Two studies have found that snuff users, as opposed to smokers, do not have increased intima-media thickness or atherosclerotic lesions when investigated by ultrasound. Results on the risk for myocardial infarction have provided conflicting evidence, 2 case-control studies showing the same risks as in non-tobacco users and one cohort study showing an increased risk for cardiovascular death. In all, the use of smokeless tobacco (with snuff being the most studied variant) involves a much lower risk for adverse cardiovascular effects than smoking does. Whether or not the apparent risk reduction is a useful strategy to help inveterate smokers to quit is a matter of debate, as are the public health effects of a high prevalence of snuff use in some populations.

Smokeless nicotine administration does not result in hypertension or a deterioration in glucose tolerance or insulin sensitivity in juvenile rats

We have previously reported that smokeless nicotine resulted in hypertension, but not a deterioration in glucose tolerance or insulin action in young adult male rats. To evaluate the effect of nicotine in juvenile animals, we studied 6-week-old male and female Sprague-Dawley rats and implanted 25-mg nicotine (N) or placebo (P) pellets. Weight gain was controlled by chow restriction in all 4 groups of rats. Males were generally heavier than females, both before and after N or P placement; there was no difference in weight between N and P groups for each sex. Systolic blood pressure, measured noninvasively, increased modestly, but not significantly, after N placement in both male and female rats. Glucose tolerance and insulin action were assessed by an oral glucose tolerance test (OGTT). Areas under the curve (AUC) were calculated for glucose (AUC(GLU)), insulin (AUC(INS)), and free fatty acids (FFA) (AUC(FFA)). Insulin action was calculated by several indices, which have correlated with more invasive studies. None of these metabolic parameters were significantly impacted by nicotine treatment, consistent with our observations in adult male rats. In summary, smokeless nicotine at this dose has no significant effect on observed cardiovascular or metabolic parameters in sexually immature male and female rats.

Spit (smokeless) tobacco use by high school baseball athletes in California

OBJECTIVE

To describe the prevalence, patterns, and correlates of spit (smokeless) tobacco (ST) use in a sample of high school baseball athletes in California.

DESIGN

This cross sectional study was a survey of 1226 baseball athletes attending 39 California high schools that were randomly selected from a list of all publicly supported high schools with baseball teams. At a baseball team meeting, athletes who agreed to participate and had parental consent completed the study questionnaire. To enhance the accuracy of self reported ST use status, a saliva sample was collected from each subject. The questionnaires and saliva samples were coded and salivary cotinine assay was performed on a random subsample of 5% of non-users who also were non-smokers. Biochemical assay indicated that 2% tested positive for cotinine inconsistent with self reported ST non-use.

RESULTS

Overall, 46% had ever used ST and 15% were current users. Odds ratios and 95% confidence intervals (CI) suggested that, among high school baseball athletes, age, living in a rural area, being white, smoking cigarettes, drinking alcohol, not knowing about the adverse effects of ST, perceiving little personal risk associated with ST use, and believing that friends, role models, teammates, and same age baseball athletes in general used ST, increased the likelihood of being an ST user.

CONCLUSION

The findings indicate that considerable experimentation with ST products occurs among high school baseball athletes in California, and many are current users. ST interventions targeting this population are needed to stop the transition from experimental ST use to tobacco dependence. Correlates of ST use for consideration in future intervention studies are identified.

Smokeless tobacco as a possible risk factor for myocardial infarction: a population-based study in middle-aged men

OBJECTIVES

To explore whether the use of snuff affects the risk of myocardial infarction (MI).

BACKGROUND

Snuff and other forms of smokeless tobacco are widely used in some populations. Possible health hazards associated with the use of smokeless tobacco remain controversial.

METHODS

In a population-based study within the framework of the Northern Sweden center of the World Health Organization Multinational Monitoring of Trend and Determinants in Cardiovascular Disease (WHO MONICA) Project, tobacco habits were compared in 25- to 64-year-old men with first-time fatal or nonfatal MI and referent subjects matched for age and place of living (687 cases, 687 referents).

RESULTS

The unadjusted odds ratio (OR) for MI in regular cigarette smokers as compared with men who never used tobacco was 3.65 (95% confidence interval [CI] 2.67 to 4.99). When nonsmoking regular snuff dippers were compared with never-users of tobacco, the unadjusted OR was 0.96 (0.65 to 1.41). After adjustment for multiple cardiovascular risk factors, the OR was 3.53 (95% CI 2.48 to 5.03) for regular smoking and 0.58 (95% CI 0.35 to 0.94) for regular snuff dipping. Restricting the analyses to fatal cases of myocardial (including sudden death) showed a tendency towards increased risk among snuff dippers 1.50 (95% CI 0.45 to 5.03).

CONCLUSIONS

The risk of MI is not increased in snuff dippers. Nicotine is probably not an important contributor to ischemic heart disease in smokers. A possible small or modest detrimental effect of snuff dipping on the risk for sudden death could not be excluded in this study due to a limited number of fatal cases.

Alcohol usage in sport and exercise

In this review we consider some of the acute and chronic effects of alcohol on human exercise and sport performance. The 1982 position stand of the American College of Sport Medicine on the use of alcohol in sport emphasized that there was little benefit for an athlete. Subsequent literature continues to demonstrate that there are adverse effects on performance. However, the literature is often confusing and disparate. We will attempt to explain the effects and speculate on the possible mechanisms. We divide the review into acute and chronic metabolic and physiological effects of alcohol on exercise performance, primarily in humans. We also review the epidemiological evidence of the associations between alcohol use and problem alcohol behaviors in various athletic groups. Finally, we review the limited data on the effectiveness of exercise therapy in the treatment of alcohol dependent patients. In spite of scientific evidence that alcohol use is, in general, detrimental (or of no benefit) to sport (exercise) performance, alcohol continues to be used by athletes both on a chronic basis and even immediately prior to sports participation. There is some encouraging but limited evidence that student-athlete alcohol use is decreasing and exercise can be effective as part of alcohol rehabilitation.

Oral spit tobacco: addiction, prevention and treatment

The prevalence of smokeless tobacco is significant and reaches as high as 17% past month use in white males aged 18-25. Smokeless tobacco use is of concern because of the potential for addiction and the associated negative health consequences. This article reviews the basis for addiction to smokeless tobacco, examining the nicotine content in smokeless tobacco products, pharmacokinetics, psychoactive effects, tolerance, and withdrawal. It also explores the negative health consequences which include a number of oral pathologies and increased cardiovascular risk factors. Furthermore, it examines the factors associated with the initiation of smokeless tobacco use, and the current prevention programs that address these factors. Current smokeless tobacco treatment approaches are also discussed as well as predictors for abstinence. Finally, the future directions are discussed in light of the limited amount of research that has been conducted in the smokeless tobacco area, particularly related to prevention and treatment.

Simple and sensitive method for determination of nicotine in plasma by gas chromatography

Smoking and other forms of nicotine consumption are among the most important risk factors for cardiovascular disease and cancer. Many of the cessation therapies require administration of nicotine. Accordingly, precision analysis for nicotine in plasma has become increasingly important. Several of the recently published methods require elaborate sample handling and/or processing. We report a simple, rapid and reliable gas chromatography method with a high sensitivity for determination of unchanged nicotine in plasma, which can be used in the processing and quantification of large series of nicotine samples, e.g., in clinical trials of nicotine-based smoking or tobacco cessation drug delivery systems.

Injury proneness in infantry conscripts undergoing a physical training programme: smokeless tobacco use, higher age, and low levels of physical fitness are risk factors

Musculoskeletal injuries represent an adverse event of strenuous physical activity. The aim of the present study was to identify pretraining factors that may predispose to such injuries. Risks of injury according to age, body composition, previous physical activity, physical fitness, use of smokeless tobacco (moist snuff) and smoking habits were determined in a population of 480 male conscripts in the army. Data were obtained by questionnaire, height and weight measurements, and from a 3000-metre run test prior to a 10-week period of basic military and physical training. Injuries were registered by doctors attached to the training camp. Every fourth conscript sustained one or more musculoskeletal injuries during the training period. Low back pain, overuse knee injuries, Achilles tendinitis, and sprains of joint capsules or ligaments were the most frequent diagnosis groups. Subjects aged 22 years and more, the least active persons before call-up, those who thought they were less fit than the average, the slowest one-third in the 3000-metre run test, smokers of more than 10 cigarettes a day, and snuff-takers suffered more injuries according to univariate analyses. Multiple logistic regression analysis showed that age, self-assessed physical fitness and snuff-taking were mutually independent risk factors of high statistical significance.

Smokeless nicotine administration is associated with hypertension but not with a deterioration in glucose tolerance in rats

Cigarette smoking is a major risk factor for coronary heart disease. To further investigate the relationship of nicotine with other cardiac risk factors, we studied the impact of nicotine on blood pressure and glucose tolerance. Adult male Sprague-Dawley rats were randomly assigned to receive nicotine or placebo pellets implanted subcutaneously. Weight gain was controlled by pair-feeding, and was not significantly different between nicotine- and placebo-treated animals. Blood pressure (in mm Hg) increased throughout a 3-week treatment period in nicotine-treated animals and was significantly higher [P < .05 by two-way ANOVA] than in placebo-treated rats. Blood pressure returned to normal within 1 week following exhaustion of the pellets. Oral glucose tolerance tests performed 2.5 weeks after pellet placement showed similar glucose, insulin, and free fatty acid (FFA) profiles by two-way ANOVA. In summary, smokeless nicotine exposure leads to sustained but reversible hypertension without deterioration in glucose tolerance or insulin action when weight gain is controlled. We conclude that in rats smokeless nicotine adversely affects the coronary risk profile by increasing blood pressure.

Epidemiology of cancer and other systemic effects associated with the use of smokeless tobacco

Persons who use chewing tobacco and snuff experience an increased risk of oral cancer. Because of the pharmacologic properties of nicotine and other constituents of smokeless tobacco, there is also concern that smokeless tobacco products may lead to cardiovascular diseases as well. The relatively few human population studies to date conflict with respect to whether smokeless tobacco use elevates cardiovascular risk factors or leads to cardiovascular disease or death from cardiovascular causes. Hemoglobin adducts to carcinogens present in smokeless tobacco products are measurable in the blood of smokeless tobacco users, indicating that smokeless-tobacco-related carcinogens circulate throughout the body. This prompts a concern that smokeless tobacco may increase risks of other cancers as well. The evidence to date from epidemiologic studies indicates no relationship between smokeless tobacco and bladder cancer, but there is suggestive evidence linking smokeless tobacco use to prostate cancer risk. Only single studies have been conducted of some cancers, and inconsistencies among studies of the same cancer site have been reported. Molecular epidemiologic studies may help identify markers of malignant transformation in smokeless tobacco users that may help in early intervention to prevent or ameliorate the consequences of oral cancer. Further studies are needed to determine more clearly the cardiovascular and non-oral cancer risks potentially associated with smokeless tobacco use.

Systemic absorption and effects of nicotine from smokeless tobacco

Nicotine is absorbed in substantial quantities from smokeless tobacco and could contribute to the adverse consequences of smokeless tobacco use. Chronic systemic exposure to nicotine could contribute to accelerated coronary artery disease, acute cardiac ischemic events, and hypertension. Systemic absorption of sodium and mutagenic chemicals from smokeless tobacco could aggravate hypertension or cardiac failure, or contribute to cancer, respectively. Information concerning the potential hazards of nicotine and other systemically absorbed toxins may be incorporated into educational programs to discourage the use of smokeless tobacco.

Effect of nicotine on lipoprotein metabolism in rats

Nicotine, a major component of cigarette smoke, plays an important role in the development of cardiovascular disease and lung cancer in smokers. The effect of nicotine on lipoprotein metabolism was studied using rats as the experimental animal. There was a significant increase in the total cholesterol, phospholipids, and triglycerides as well as the amount of lipids associated with very low density lipoprotein (VLDL) and low density lipoprotein (LDL) in sera of nicotine-treated rats. The incorporation of 3H labeled leucine into the apo B was found to be increased both in the medium and associated cells in the hepatocytes isolated from nicotine-treated rats indicating an increased synthesis and secretion of the apo B containing lipoproteins. This was further confirmed by the higher incorporation of 14C acetate into total and individual lipids of LDL and VLDL secreted into the medium as well as that associated with different lipids in the cell layer. The activity of lipoprotein lipase in extrahepatic tissues and plasma lecithin cholesterol acyl transferase activity were significantly lower in nicotine-treated rats. These results indicate that nicotine exerts hyperlipidemic effects particularly by increasing the synthesis and secretion of triglyceride-rich lipoproteins. Since nicotine is one of the major hazardous components present in cigarette smoke and tobacco, one can extrapolate that the deleterious effect exerted by nicotine on rats extends to cigarette smokers and those who use other forms of tobacco.