Enhancement of preheparin serum lipoprotein lipase mass by bezafibrate administration

To clarify the clinical implication of preheparin serum lipoprotein lipase mass (preheparin LpL mass), we studied the relationships between preheparin LpL mass and serum lipids, including midband lipoproteins, which migrate between very low density lipoproteins and low density lipoproteins on polyacrylamide gel disc electrophoresis, in hyperlipidemias. And we also studied the changes of preheparin LpL mass in hypertriglyceridemic patients during bezafibrate administration, which is known to enhance LpL activity in postheparin plasma. Preheparin LpL mass correlated positively with high-density lipoprotein-cholesterol (HDL-C) (r=0.418, P<0.01) and negatively with triglyceride (TG) (r=-0.256, P<0.01), but did not correlate with total cholesterol (TC) in 64 hyperlipidemic (type IIa, IIb and IV) patients. The midband lipoproteins were observed in 80% of hypertriglyceridemic patients (32/40). Preheparin LpL mass in midband lipoprotein-positive subjects was lower significantly than that in midband-negative subjects. When bezafibrate (400 mg/day) was administrated to 40 hypertriglyceridemic patients for 4 months, TG level significantly decreased (-49+/-7%, P<0.01), TC levels decreased (-11+/-4%, not significant), and HDL-C levels increased (+27+/-4%, P<0.01). The midband lipoproteins disappeared in 95% of patients. Preheparin LpL mass significantly increased (+25+/-6%, P<0. 0005). In nine patients who stopped bezafibrate, TG levels significantly increased (+49+/-7%, P<0.01) and HDL-C levels decreased (-27+/-4%, P<0.01). Preheparin LPL mass significantly decreased (-25+/-6%, P<0.0005). These results suggested that bezafibrate administration enhanced preheparin LpL mass. And it might be implicated that enhanced LpL production by bezafibrate could reflect an increase of preheparin LpL mass.