Rosiglitazone-Induced Weight Gain

Given the high prevalence of type 2 diabetes and the 2- to 4-fold increased risk of fatal and non-fatal coronary heart disease events in these patients, long-term glycemic control is of great importance. TZDs improves glycemic control in patients with type 2 DM as well as enhances their insulin-mediated glucose disposal. However, the improvement of glycemic control seen with TZDs may be blunted in the long run by weight gain. Previous data on weight gain during TZD therapy in patients with type 2 DM is very sparse. It is generally assumed that an increase in adipocyte differentiation is the cause of weight gain in association with TZD treatment which may limit their use. Increased body weight assumed to compromise the positive effects of treatment. There is also a theoretical concern that, with the development of new adipocytes, future weight loss may be difficult. However, if weight gain is primarily due to failure to adjust caloric intake in proportion to the decrease in urinary glucose loss, it is totally preventable. It has been previously shown that improvement of glycemia favored weight gain by decreasing the energy loss in the urine as glucose. Severity of weight gain appears to be proportional to the level of glycemic control achieved. The overall goal of the proposed research is to provide the experimental evidence for the later alternative by showing that the modest weight gain that takes place in association with effective rosiglitazone treatment of hyperglycemic patients with type 2 DM is primarily due to its therapeutic efficacy. More specifically, by decreasing the caloric intake in proportion to a decrease in urinary glucose loss associated with improved glycemic control, we will be able to prevent significant weight gain following Rosiglitazone treatment. In order to provide an optimal dietary modification that can be universally applied to TZD-treated patients in clinical practice, we will have a group with a fixed amount of caloric restriction per day. It will be the first randomized controlled trial of a potential strategy for prevention of weight gain associated with thiazolidinediones.