Endocrine Abstracts

Background and aims: Thiazolidinediones have been extensively used as second line agents in the management of type 2 diabetes. A small increased incidence of ischaemic heart disease was suggested by a meta-analysis of studies using Rosiglitazone. Similar meta-analysis of Pioglitazone did not show adverse cardiovascular outcomes. Our aim was to objectively evaluate the changes in glycaemic and lipid control in a controlled conversion from Rosiglitazone to Pioglitazone.

Materials and methods: Thirty-five patients identified from Primary and Secondary care were converted from Rosiglitazone (4 or 8 mg) to equivalent dose Pioglitazone (30 or 45 mg). Blood tests taken at baseline and 3 to 6 months late for fasting plasma glucose, HbA1c, liver function tests, full lipid profile and creatinine. Apolipoprotein-B total cholesterol:HDL and non-HDL were taken as additional markers of cardiovascular risk. Patients requiring additional treatment changes for their glycaemic or lipid control during this period were excluded from the analysis.

Results: Using paired Wilcoxon two-tailed, conversion from Rosiglitazone to Pioglitazone resulted in a significant improvement in mean fasting plasma glucose from median of 7.8 to 6.3 mmol/l (P=0.005) and median HbA1c from 7.2 to 6.8% (P=0.0001). Lipid parameters also showed a significant improvement with median total cholesterol falling from 4.1 to 3.9 mmol/l (P=0.0013), and HDL cholesterol from 1.0 to 1.2 mmol/l (P=0.0008) with non-HDL levels falling from 3.1 to 2.6 mmol/l (P<0.0001). Overall total cholesterol:HDL cholesterol fell from 3.9 to 3.4 with P<0.0001. ApoB levels (20 cases) improved from 0.7 to 0.6 g/l (P=0.0023). Improvement in triglycerides was also significant (1.6–1.1 mmol/l, P=0.0179).

Conclusions: Our data in a real clinical setting suggests that Pioglitazone is more effective than Rosiglitazone at plasma glucose control. Pioglitazone also showed better lipid profiles. There is clinical merit in converting patients to Pioglitazone.