It is widely known that
atherosclerosis through its complication, i.e. heart and
brain infarction, is at the present the main cause of death. The atherosclerotic process has been shown in correlation with
hyperlipemia especially as far as the plasma
lipoprotein cholesterol level is concerned. A
preminent role in removing
cholesterol from tissues and arterial walls then in preventing
atherosclerosis is played by a specific class of plasma
lipoproteins, the
high density lipoproteins (HDL). Since the HDL-colesterol level seems to have an inverse correlation with the atherosclerotic disease it is of primary importance to define a reliable and reproducible technique to measure it. One of the aims of this paper was to examine the different methods now available for such a determination. This analysis has underlined the discrepancy among the reference values reported in the literature. However, all the authors agree that only the simultaneous measurement of total and HDL-colesterol levels is of prognostic value. Personal studies are here reported on the relationship between total and HDL-colesterol levels and risk factor of
cardiovascular diseases. The two mentioned laboratory analyses have been performed on blood samples from 250 between male and female human subjects of different age. The obtained results show that the highest HDL-colesterol concentrations determined by a
lipoprotein precipitation procedure with
dextran sulphate, are typical in the first ten years of life both in male and in female, while the lowest levels of plasma
HDL-cholesterol have been evintiated during the fifth decade of life, when the total
cholesterol and the risk of cardiovascular complications rich the highest values. In a following set of investigations, the already examined blood parameters together with the risk factor values have been examined in two groups of subjects, the first one represented by adult healthy persons the second one by patients of similar age from a cardiovascular division. The mean levels of total colesterol have been shown similar in both the experimental groups, while plasma
HDL-cholesterol is significantly higher in the healthy group. This discrepancy is the cause of definitively higher risk factors in the hospitalized patients. In conclusion, the reported data furtherly stress that the total
cholesterol values do not give "per se" any indication of atherogenic risk. They are useful only when examined together with the
HDL-cholesterol levels. From that the opportunity to always include the determination of plasma
HDL-cholesterol screening lipemic profiles.