EFFECT OF BEZAFIBRATE ON HDL WITH APO A-I AND APO A-II AND ON HDL WITH APO A-I WITHOUT APO A-II IN HYPERLIPIDEMIC PATIENTS

On the basis of apoprotein composition, high-density lipoprotein (HDL) particles may be subdivided into two main subpopulations defined by t he presence in the lipoprotein molecule of apo A-I (Lp A-I) and of bot h apo A-I and apo A-II (Lp A-I:A-II). The effect of slow-release bezaf ibrate 400 mg a day on Lp A-I and Lp A-I:A-II was evaluated in 34 hype rlipidaemic patients (19 with hypercholesterolaemia and 15 with hypert riglyceridaemia). Seventeen patients on low-fat low-cholesterol diet o nly were taken as the reference group. In the reference group, no chan ge in HDL-C, apo A-I, apo A-II, Lp A-I and Lp A-I:A-II occurred during the 3 months of observation. In patients on bezafibrate, HDL-C, apo A -I and apo A-II significantly increased. Lp A-I:A-II increased by 33% in hypercholesterolaemic and by 29% in hypertriglyceridaemic patients. Lp A-I decreased by 15% in hypercholesterolaemic patients and did not change significantly in hypertriglyceridaemic patients. This differen tial effect of bezafibrate on apo-A-defined HDL subpopulations in hype rtriglyceridaemia and in hypercholesterolaemia is in accord with previ ous studies on the effect of the drug on HDL subfractions defined by t heir density.