The effect of pioglitazone as add-on therapy to metformin or sulphonylurea compared to a fixed-dose combination of metformin and glibenclamide on diabetic dyslipidaemia

Background and aims: Diabetic dyslipidaemia contributes to the increased risk of cardiovascular disease in patients with Type 2 diabetes. This paper examines the effectiveness of adding pioglitazone to metformin or a sulphonylurea (SU) compared with a fixed-dose combination of metformin and glibenclamide on diabetic dyslipidaemia in patients with Type 2 diabetes. Methods and results: Patients (n = 250) treated with metformin (<= 3 g/day) or an SU as monotherapy at a stable dose for >= 3 months were randomised to receive either pioglitazone (1530 mg/day) in addition to their metformin or SU, or a fixed-dose combination tablet containing metformin (400 mg) and glibenclamide (2.5 mg) [up to 3 tablets daily] for 6 months. Addition of pioglitazone tended to increase plasma high-density lipoprotein-cholesterol (HDL-C) [0.04 mmol/L; P = 0.051] at 6 months and significantly reduced plasma triglycerides (-0.25 mmol/L; P = 0.013) compared with baseline. Patients treated with metformin/glibenclamide for 6 months had reduced HDL-C (-0.09 mmol/L; P < 0.01) and no change in plasma triglyceride levels (0.03 mmol/L; P = 0.733). Both treatment regimes resulted in a similar level of glycaemic control.