Background: Tobacco smoking is an important risk factor for ischemic heart disease. In India, tobacco is smoked both as cigarettes and beedies. No studies have evaluated their importance as risk factors for ischemic heart disease among the Indian population. The present study explores the importance of smoking either cigarettes or beedies as risk factors for acute myocardial infarction.
Methods and results: The study had a case-control design and was conducted in a tertiary teaching hospital in Bangalore. Three hundred subjects aged 30-60 years with a first acute myocardial infarction and 300 age- and sex-matched controls were recruited prospectively. Smoking, dietary and social history were recorded, body mass index and waist-hip ratio measured, and blood glucose, lipids, fasting plasma and insulin levels estimated. Cases and controls had a mean age of 47.2 years and 46.8 years, respectively. There were 279 (93%) males in each group. Diabetes mellitus (odds ratio 2.69, p<0.0009). hypertension (odds ratio 2.36, p=0.0009), fasting and post-load blood glucose (p<0.0001). and waist-hip ratio (p<0.0001) were found to be important risk factors for acute myocardial infarction. Smoking was an independent risk factor with a clear dose effect. Adjusted odds ratio for smoking > or = 10 cigarettes/day was 3.58 (p<0.0001) and was 4.36 (p<0.0001) for smoking > or = 10 beedies/day.
Conclusions: Smoking > or = 10 cigarettes or beedies/day carries an independent four-fold increased risk of acute myocardial infarction. This reiterates the need for urgent tobacco control measures in India.