[Plasma cholesterol levels and ischemic heart disease: new findings and new approaches]

The information explosion characteristic of recent years has presented a series of findings enabling a more effective prevention of ischemic heart disease by controlling low density lipoprotein (LDL) levels of cholesterol. The detection of LDL receptors has provided new information on the mechanisms regulating the level of plasma LDL. Data on competitive inhibitors of endogenous cholesterol synthesis have afforded new possibilities of pharmacological control of LDL levels. Studies of primary prevention of ischemic heart disease have yielded evidence showing that a 1% decrease of cholesterol level reduces coronary risk by 2%. A prospective study of the relationship between cholesterol levels and coronary mortality, absolutely unique as to its extent (368,000 middle-aged men followed up over a period of 6 years) has demonstrated that there is no borderline cholesterol level below which coronary risk would be absolutely excluded. Between total cholesterol level and coronary mortality there is a close, continual and graded relationship. In light of these findings, total cholesterol levels have been reclassified: desirable levels -5.2 x 10(-3) mol.l-1, borderline risk levels under 5.2-6.2 x 10(-3) mol.l-1, and high risk levels--above 6.2 x 10(-3) mol.l-1. In subjects with several risk factors (smoking, hypertension, familial occurrence of heart, heart disease, obesity, diabetes mellitus, HDL cholesterol below 0.9 x 10(-3) mol.l-1) the level of total cholesterol should be brought down below 4 x 10(-3) mol.l-1.(ABSTRACT TRUNCATED AT 250 WORDS)