Alcohol consumption, drinking pattern and acute myocardial infarction. A case referent study based on the Swedish Twin Register

Objectives. Little is known about the possible influence of different kinds of alcohol drinking pattern on the risk of acute myocardial infarction. In this study the association between average daily alcohol consumption, as well as large intakes of alcohol on single occasions, and myocardial infarction incidence was investigated.
Design. A case referent analysis nested within a prospective cohort study.
Setting. Incident cases of myocardial infarction were identified by using hospital discharge data and deaths. Referents were selected from the study population through a stratified random sample.
Subjects. Individuals of the Swedish Twin Register below 75 years of age living in a region of 10 Swedish counties in 1972–1981 or in Stockholm County in 1972–1987.
Main outcome measure. Incidence of acute myocardial infarction.
Results. No difference in myocardial infarction incidence was found between former alcohol drinkers and lifelong abstainers. For men, drinkers had a 40% lower incidence than non-drinkers, as did those with a drinking pattern involving a large intake on single occasions. Women had on average a very low level of alcohol consumption and there were only small differences in incidence of myocardial infarction between drinkers and non-drinkers. An increased incidence was indicated for women reporting sometimes drinking comparatively large amounts of alcohol on single occasions.
Conclusions. The results support the suggestion that low and moderate alcohol consumption is protective for myocardial infarction. A drinking pattern involving a large intake of alcohol on single occasions did not seem to substantially influence myocardial infarction incidence except possibly for women with an overall very low level of consumption.