Smokeless tobacco and cardiovascular disease in low and middle income countries

Abstract

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.

Keywords: Cardiovascular disease; Smokeless tobacco; Smoking: coronary heart disease; Tobacco.

Fig. 1

Smoking and tobacco use among adults in different regions of the world.

Fig. 2

Smokeless tobacco use and risk of fatal myocardial infarction (upper graph) or fatal stroke (lower graph) in high income countries. Summary meta-analysis odds ratio statistic and 95% confidence intervals (CI) show greater risk of fatal stroke (1.40, CI 1.28–1.54) as compared to fatal myocardial infarction (1.13, CI 1.06–1.21).

Fig. 3

Smoking, smokeless tobacco use and cardiovascular mortality in India: Mumbai Cohort Study. Smokeless tobacco use in women is significantly associated with cardiovascular mortality (relative risk 1.19, 95% CI 1.02–1.38) while the association is not significant in men (relative risk 0.94, 95% CI 0.82–1.09).

Fig. 4

Smokeless tobacco use and cardiovascular mortality in Asian countries. Studies from China, Taiwan and India have reported significant association of tobacco use and cardiovascular mortality in cohort studies. Summary odds ratio (1.26, CI 1.12–1.40) indicates moderate risk.

Fig. 5

Cardiovascular risk factors in smokers, smokeless tobacco users and non-tobacco users in India. Greater prevalence of hypertension, hypercholesterolemia, low HDL cholesterol, hypertriglyceridemia and diabetes is observed among smokeless tobacco users vs non-tobacco users (p < 0.05). Prevalence of risk factors is similar to smokers.