Objectives: To assess the relation between cigarette smoking, alcohol, coffee, decaffeinated coffee and tea consumption, and the risk of non-fatal acute myocardial infarction (AMI).
Design and setting: Hospital-based case-control study conducted in 1995-1999 in Milan, Italy.
Patients: 507 cases with a first episode of non-fatal AMI, and 478 controls admitted to hospital for acute diseases.
Methods: Information was collected by interviewer-administered questionnaires. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by multiple logistic regression.
Results: Compared to alcohol non-drinkers the OR was 0.6 (95% CI: 0.4-0.9) in drinkers, and 0.5 in drinkers of > 3 drinks/day. The OR for > 1 drink/day of wine was 0.5, and those for beer, amari, grappa and spirits ranged between 0.4 and 0.6. Compared to never smokers, the OR was 2.2 (95% CI: 1.5-3.1) among current smokers, and 4.6 among current smokers of > or = 25 cigarettes/day. The risk was similar to that of never smokers > or = 5 years after cessation (OR: 1.1 after 5-9 years, 0.7 after > or = 10 years). The OR was 2.3 for low tar cigarettes and 2.0 for high tar ones. The OR for coffee intake (expresso and mocha) was around unity up to 3 cups/ day, but rose to 1.9 (95% CI: 1.1-3.3) for > or = 6 cups/ day. Moderate decaffeinated coffee and tea intake was not associated with AMI risk. Compared to non-smokers drinking < or = 3 cups of coffee/day, the OR was 1.6 among non-smokers drinking > 3 cups of coffee/ day and 3.3 (95% CI: 2.1-5.0) among current smokers drinking < or = 3 cups of coffee/day. Compared to alcohol drinkers with a coffee intake of < or = 3 cups/ day, alcohol non-drinkers with higher coffee intake had an OR of 2.2, and compared to non-smokers alcohol drinkers, the OR was 3.3 in current smokers alcohol non-drinkers.
Conclusions: In this Italian population alcohol intake was inversely associated to AMI risk, while smoking and heavy (but not moderate) coffee drinking increased the risk.