A case-control study of acetaminophen use in relation to the risk of first myocardial infarction in men.

PURPOSE: Experimental evidence raises the possibility that acetaminophen use could reduce the risk of myocardial infarction (MI). We assessed the relation of acetaminophen use, and also of aspirin use, to first MI in a case-control study.

METHODS

Data on analgesic use and other factors were collected in a hospital-based case-control study of first MI in men under 55 years of age conducted from 1980 to 1983. We compared 2035 men with first MIs to 2656 control men admitted for conditions unrelated to analgesic use. Odds ratios (ORs) for acetaminophen use relative to nonuse were estimated with logistic regression analysis, controlling for major MI risk factors.

RESULTS

The OR was 0.9 (95% confidence interval (CI): 0.6-1.3) for acetaminophen use at least once a week for at least 3 months, 0.7 (95% CI: 0.4-1.1) for daily use for at least 3 months, and 0.5 (95% CI: 0.2-1.6) for daily use for at least 5 years. In analyses of aspirin use, the OR was 0.9 (95% CI: 0.7-1.2) for use at least once a week for at least 3 moths, 0.9 (95% CI: 0.6-1.2) for daily use lasting at least 3 months, 0.6 (95% CI: 0.4-1.1) for daily use for at least 5 years, and 0.4 (95% CI: 0.2-1.0) for daily use for at least 10 years.

CONCLUSIONS

While our results raise the possibility of a protective effect of long-term regular acetaminophen use against first MI, they are compatible with no effect. The data suggest a potential protective effect of long-term regular aspirin use.