Decaffeinated coffee and acute myocardial infarction. A case-control study in Italian women

The relationship between consumption of decaffeinated coffee and acute myocardial infarction was analyzed in a case-control study conducted in Italy between 1983 and 1992. Case patients were 433 women with acute myocardial infarction, aged 24 to 69 years (median age, 52 years), and control subjects included 869 women in hospital for a wide spectrum of acute conditions, other than cardiovascular, neoplastic, digestive, and hormone-related diseases or conditions associated with long-term modification of diet. Regular use of decaffeinated coffee was reported by 11% of the case patients and 7% of the control subjects. Compared with women who did not drink decaffeinated coffee, the relative risk (RR) was 1.3 (95% confidence interval (CI), 0.8 to 2.2) for one cup/d and 2.1 (95% CI, 1.1 to 3.9) for 2 or more cups (chi 2(1) for trend = 5.62, P = 0.02). The estimates were somewhat higher after allowance for education, marital status, body mass index, and smoking status (RR for > or = 2 cups of decaffeinated coffee per day, 2.5; 95% CI, 1.2 to 4.9), and somewhat lower after further allowance for diabetes, hypertension, and hyperlipidemia (RR, 1.7; 95% CI, 0.8 to 3.6). There was no association between duration of use of decaffeinated coffee and infarction risk. The relationship between decaffeinated coffee and infarction was consistent across strata of age, education, smoking, and history of hyperlipidemia. Thus, a relationship of marginal significance was observed in this study between decaffeinated coffee and myocardial infarction, of similar magnitude to that described for caffeinated coffee. This indicates that (i) caffeine is unlikely to be a relevant factor in any potential coffee-myocardial infarction relationship, and (ii) shifting from caffeinated to decaffeinated coffee is unjustified in order to reduce any possible coffee-related infarction risk.