Effects of cholesterol-lowering treatments on oxidative modification of plasma intermediate density lipoprotein plus low density lipoprotein fractionin Type 2 diabetic patients

To investigate the normalization of enhanced oxidative modification of the lipoprotein such as increased lysophosphatidylcholine (LPC) and lipid hydro peroxide (LPO) contents in diabetic subjects, we studied the effect of chol esterol-lowering treatment on those parameters in 24 hypercholesterolemic T ype 2 diabetic patients. Those patients were randomly assigned to two treat ment groups, such as 12 patients treated with pravastatin 10 mg daily and 1 2 patients treated with probucol 500 mg daily for 8 weeks. Characteristics of the patients including age, gender, body mass index (BMI), smoking habit , modality of diabetic treatment and the glycemic control state were compar able between the two groups. LPC content in the lipoprotein fractions obtai ned from 24 patients with Type 2 diabetes mellitus was significantly higher than that of non-diabetic control subjects. The abnormality was improved t o the control level after a significant improvement of serum cholesterol le vels following 8 week-treatments with either probucol or pravastatin withou t any change in glycemic control (P < 0.025). Furthermore, increased LPO co ntent in the lipoprotein fraction in those diabetics was also significantly (P < 0.0025) improved by the probucol treatment and tended to be improved by pravastatin treatment (P = 0.06). LPC contents in the lipoprotein fracti on was positively correlated with LPO contents before cholesterol-lowering treatments (r = 0.41, P < 0.05). These results indicate that cholesterol-lo wering treatments effectively reduce oxidative modification of the lipoprot ein fraction containing intermediate density lipoprotein (IDL) and low dens ity lipoprotein (LDL) in hypercholesterolemic Type 2 diabetic patients. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.