The Oxidative Susceptibility of Low-density Lipoprotein in Hyperlipidemic Patients and the Role of Lipid-regulating Drugs

Objective To investigate the effects of hypertriglyceridemia and hypercholesterolemia on the oxidative susceptibility of low density lipoprotein (LDL) and the effects of micronised fenofibrate and pravastatin on LDL oxidative susceptibility in hypertriglyceridemic and hypercholesterolemic patients Methods LDL was separated by a short run density gradient ultra centrifugation from the plasma of 11 hypertriglyceridemic patients before and after the treatment with micronised fenofibrate at a dose of 200 mg/d for 4 weeks 10 hypercholesterolemic patients before and after pravastatin therapy at a dose of 10 mg/d for 4 weeks and 6 healthy subjects as controls CuCl 2 (10 μmol/L) induced oxidation of LDL was used to measure the rate of LDL oxidation and the lag time required for the initiation of LDL oxidation Results (1)In terms of LDL oxidative kinetics, lag time in the hypertriglyceridemic group and hypercholesterolemic group were both shortened significantly compared with that in the controls(43 8±11 6 min, 40 8±10 7 min vs 70 5±14 6 min, P 0 01) The rate of LDL oxidation in the hypertriglyceridemic group and hypercholesterolemic group were much increased compared with that in the controls (0 036±0 004 O D /min,0 031±0 011 O D /min vs 0 020±0 011 O D /min, both P 0 05) (2)After the treatment with micronised fenofibrate in hypertriglyceridemia patients, the lag time was prolonged (62 4±5 0 min, P 0 01) and the rate of LDL oxidation slow down(0 031±0 003 O D /min, P 0 05) (3)In patients with hypercholesterolemia, the lag time was significantly prolonged(58 8±6 1 min, P 0 05), however, the rate of LDL oxidation was not slow significantly after pravastatin therapy(0 025±0 009 O D /min, P 0 05) Conclusion LDL are more susceptible to oxidative modifications both in hypertriglyceridemic or hypercholesterolemic patients The oxidative effect of LDL should be attenuated by the treatment with micronised fenofibrate or pravastatin