RÉSUMÉ
BACKGROUND : Influence of habitual tobacco chewing on cardiovascular risk has not been well studied. To determine prevalence of major cardiovascular risk factors in subjects who habitually chew tobacco we performed a controlled study. METHODS : A population based case-control study was performed in Bikaner in North-western India where the prevalence of tobacco-chewing is high. Successive 200 subjects who agreed to participate in the evaluation and had a history of isolated tobacco-chewing (range 10-60 years) were enrolled (Group III). The prevalence of major coronary risk factors- obesity, truncal obesity, hypertension, fasting hyperglycemia, and lipid levels were estimated using current guidelines. Electrocardiogram was also performed in all subjects. Chest radiography and treadmill stress test was done in subjects when indicated by symptoms. 200 age- and gender-matched controls who did not use tobacco in any form (Group I) and 200 subjects who had history of smoking bidis or cigarettes for more than 10 years (range 10-55 years) (Group II) were also evaluated. RESULTS: The body-mass index and obesity were lowest in smoker group. Tobacco chewers had a significantly higher (p<0.001) systolic blood pressure (BP), diastolic BP, resting heart rate, total cholesterol, LDL cholesterol and triglycerides as compared to controls and was similar to smoker group. There was a significantly greater (p<0.01) prevalence of hypertension, hypercholesterolemia, hypertriglyceridemia, radiographic cardiomegaly and positive stress test in Group III as compared to controls. Prevalence of these risk factors was similar among Group II and Group III subjects. HDL cholesterol levels were the lowest in tobacco-chewing group (44.3+/-8.1 mg/dl) as compared to the Group I (48.4+/-7.8) and Group II (47.4+/-7.5) (p<0.001). CONCLUSIONS : There is a significantly greater prevalence of multiple cardiovascular risk factors obesity, resting tachycardia, hypertension, high total and LDL cholesterol, and low HDL cholesterol, and electrocardiographic changes in tobacco users, chewing or smoking, as compared-to tobacco non-users. Chewing tobacco is associated with similar cardiovascular risk as smoking.