Indices of plasma lipoprotein metabolism in normolipidemic myocardial infarction survivors.

Background: Many patients suffering from ischaemic heart disease (IHD) were shown to be characterized by different deviations of lipoprotein metabolism without having plasma cholesterol and triglyceride levels increased. The aim of the study was to determine the parameters of lipoprotein metabolism most contributing to finding among normolipidemic men those with an elevated risk of myocardial infarction.

Results: We investigated 21 men with normal plasma cholesterol and triglyceride levels, who survived myocardial infarction (MI) in the period 6 months to 3 years before the investigation (group MI). In comparison with the control group of normolipidemic men without IHD, survivors of MI had significantly lower concentrations of HDL-C (-22%, P < 0.01), especially in HDL3 subfraction (-24%, P < 0.001), higher concentrations of apo B in LDL (+36%, P < 0.001) and lower values of cholesterol to apo B ratio in LDL (-25%, P < 0.05). The concentrations of total plasma cholesterol, triglycerides, LDL-cholesterol, HDL2-cholesterol, apo A-I and the ratio HDL-C/apo A-I did not differ significantly. Discriminant analysis revealed that for separating the two groups, determining apo B in LDL and HDL3-C was most advantageous as thus 80% patients in this set could be correctly classified.

Conclusions: These results show the significance of the investigation of apo B and HDL-C including their subfractionism HDL2 and HDL3 for the estimation of MI risk in normolipidemic men.