The effect of bezafibrate on very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), and low density lipoprotein (LDL) composition in Type 1 diabetes associated with hypercholesterolaemia or combined hyperlipidaemia

Abstract

Lipoprotein composition was examined in type 1 diabetic subjects with hypercholesterolaemia ± hypertriglyceridaemia during a 3-month double-blind placebo controlled assessment of bezafibrate therapy. The predominant effect was on lipoprotein lipid content. In those with hypercholesterolaemia alone, bezafibrate significantly reduced the cholesterol (particularly esterified cholesterol) and triglyceride content of large very low density lipoprotein (VLDL) (Svedberg flotation units (Sf) 60–400) in comparison to the placebo group ( P < 0.05), and a trend towards a reduction in free and esterified cholesterol within the intermediate density lipoprotein fraction (IDL) (Sf 12–20) was noted. Low density lipoprotein (LDL) composition was unaltered and in general phospholipid and protein concentrations and cholesteryl ester/protein ratios within the lipoprotein fractions were unaffected. Large VLDL cholesterol and triglyceride concentrations in those with combined hyperlipidaemia were significantly decreased following bezafibrate therapy, both in comparison to placebo-treated subjects and to baseline concentrations ( P < 0.05). An additional significant reduction in small VLDL (Sf 20–60) free cholesterol was recorded ( P < 0.05). Average reductions of large and small VLDL protein of 50–56% were not significant because of wide variation in responses. Bezafibrate had no effect on the abnormal composition of IDL and LDL, characteristic of Type 1 diabetes, regardless of whether or not hypertriglyceridaemia was associated with hypercholesterolaemia. Its major action was to lower VLDL lipid concentrations, but it may also reduce the lipid content of intermediate density lipoprotein in Type 1 diabetes.