High density lipoprotein alterations induced by bezafibrate in healthy male volunteers

The alterations of HDL structure and metabolism induced by bezafibrate administration were studied in healthy male volunteers. As usually observed in hyperlipaemic patients, bezafibrate induced a decrease of the plasma concentrations of apo B and LDL-cholesterol and an increase of that of HDL-cholesterol. Analysis of HDL by gradient polyacrylamide gel electrophoresis revealed that bezafibrate administration resulted in a change of the particle size distribution likely suggesting a drop of the HDL2/HDL3 ratio. This was accompanied by a 30% enhancement of the plasma concentration of apoprotein A-II, while that of apoprotein A-I remained unchanged. These data suggest an increase of the HDL concentration, preferentially in the HDL3 subfraction. In spite of these HDL alterations, there was no evidence of change in the three stages of the reverse pathway of cholesterol, since bezafibrate did not induce any significant alteration in the in vitro properties of plasma with respect to (a) cholesterol transport from cultured cells, (b) cholesterol esterification, and (c) transfer of cholesteryl esters from HDL to VLDL-LDL.