Comparison of bezafibrate and simvastatin in the treatment of dyslipidaemia in patients with NIDDM

Fibrates and HMG CoA reductase inhibitors are commonly used in the treatment of diabetic dyslipidaemia. However, these two groups of drugs have not been compared in diabetic patients in a randomized controlled trial. Therefore, a multicentre study was performed in 73 subjects with non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) and combined hyperlipidaemia (serum cholesterol 6.2-10.0 mmol l(-1), serum triglycerides 2.3-10.0 mmol l(-1)), comparing the efficacy of 400 mg bezafibrate with 10 mg simvastatin in a double-blind fashion. Treatment with bezafibrate during 12 weeks reduced serum triglycerides significantly more than simvastatin (-41% vs -22%, p textless 0.001) and increased HDL cholesterol more (bezafibrate: + 17% vs simvastatin: + 9%, p textless 0.05). LDL cholesterol levels decreased by 14% (p textless 0.001) during simvastatin and increased by 21% (p textless 0.01) during bezafibrate. This increase in LDL cholesterol was positively correlated with fasting serum triglycerides (p textless 0.001) and was associated with a reduction of the serum apolipoprotein B concentration, suggesting an increase in LDL particle size. Metabolic control of diabetes (fasting glycaemia; HbA1c) and insulin secretion (C-peptide levels) were unaffected by both treatments. The incidence of side-effects during treatment was similar for both drugs. Thus, 400 mg bezafibrate mainly increases HDL cholesterol and lowers serum triglycerides but at the expense of an increase in LDL cholesterol; 10 mg simvastatin lowers LDL cholesterin more effectively but has a smaller effect on HDL cholesterol and triglycerides.