Rationale Rosiglitazone and troglitazone both promote differentiation of pre-adipocytes into adipocytes in subcutaneous, but not omental fat, and reduce gamma glutamyl transferase, a surrogate marker for intra-abdominal and hepatic fat. Troglitazone has been shown by abdominal computed tomography (CT) and magnetic resonance imaging (MRI) scan to reduce the intra-abdominal adipose tissue area in type 2 diabetics. Similarly rosiglitazone has also been shown to increase subcutaneous but not intra-abdominal fat in patients with type 2 diabetes. In the same study it was also shown to cause a substantial reduction in hepatic fat. Central fat depots are believed to be associated with more cardiovascular risk than subcutaneous fat depots. By contrast, sulphonylurea-associated weight gain has been shown by abdominal CT scan to include increases in intra-abdominal adipose tissue.