The Münster Heart Study (PROCAM) was initiated in 1979 in order to examine cardiovascular risk factors, cardiovascular events including myocardial infarction and stroke, and mortality in people at work. Examination at entry comprised a standardized case history, measurement of blood pressure and anthropometric data, a resting electrocardiogram, and measurement of more than 20 laboratory parameters in a fasting blood sample. The prevalence data in this report are based upon a single examination of 17,437 men aged 40.4 +/- 11.3 years (mean +/- SD) and 8065 women aged 35.7 +/- 12.1 years, which took place between 1979 and 1991. Severe hypercholesterolaemia (> 300 mg.dl-1) was seen in 5% of men and 8% of women aged 45 to 64 years. In men, the prevalence of hypertriglyceridaemia (> 200 mg.dl-1) rose from 5% at age 20 to 20% at age 45 and remained constant thereafter; in women the prevalence of hypertriglyceridaemia increased linearly from 2% at age 20 to 7% at age 60. The LDL/HDL ratio was higher in men than in women at all age groups; in the age group 45 to 64 years, LDL/HDL ratios > 5 were approximately twice as common in men. Lipoprotein(a) levels were distributed in a highly skewed fashion. In men, a slight rise in the geometric mean lipoprotein(a) concentration occurred with age, whereas in women a dramatic increase was seen after age 40. Using multivariate analysis by the multiple logistic function method, total cholesterol, HDL cholesterol, LDL cholesterol and log-transformed triglycerides showed a significant (P < 0.001) age-adjusted correlation with the presence of major coronary events. A risk algorithm has been developed for men aged 40 to 65 years which takes into account the independent risk factors of HDL cholesterol, LDL cholesterol, triglycerides, fibrinogen, age, systolic blood pressure, cigarette smoking, presence of diabetes mellitus and family history of myocardial infarction and angina pectoris. This algorithm can be used in clinical practice to calculate the 8-year risk of an individual suffering a myocardial infarction.