Maintenance of the pancreas allograft over many years remains the goal in following pancreas transplant recipients over time. The onset of hyperglycemia less than one year after transplant is usually due to issues of surgical technique or acute rejection. HOwever, the onset of hyperglycemia fter one year of pancreas transplant is more problematic because the underlying causes are less clear and have been less well characterized. Currently, there is no protocol for definitively identifying the causes of hyperglycemia in pancreas transplant recipients over one year. This project will systematically characterize beta cell function and peripheral tissue response to insulin in patients who have received an earlier successful pancreas transplant who have developed hyperglycemia.