Incidence and prediction of coronary heart disease in two Italian rural population samples followed-up for 20 years.

Two rural cohorts of men initially aged 40-59, located in Northern and Central Italy for a total of 1712 subjects were followed-up for 20 years for coronary heart disease (CHD) incidence and total mortality. In 20 years the overall incidence of CHD manifestations, defined in a hierarchical way, in men CHD-free at entry, was of 4.5 per 1000 per year for CHD-deaths, of 1.9 for CHD-hard surviving, and 5.4 for CHD-soft surviving. Altogether more than 23% of men developed in 20 years one or more manifestations of CHD with one or more episodes. Eight personal characteristics measured at entry examination have been evaluated for their role of risk factors. Both univariate and multivariate analysis showed that age, serum cholesterol, systolic blood pressure, smoking habits and physical activity at work (protective) are powerful predictors of the future occurrence of the disease. Diastolic blood pressure, relative body weight and skinfold thickness showed little or no relationship with CHD incidence. The predictive power of single risk factors and the discriminating power of the multivariate models were directly related to the severity of the disease manifestations considered as endpoints. High levels of relative risk could be obtained comparing extreme classes of risk as estimated by the multivariate models. It is confirmed that some characteristics seem to be universal predictors of the disease and that their meaning is long-lasting although a single casual measurement is taken in middle age.