Patterns and Natural History of Insulin Secretion in Islet Cell Transplant Recipients and Controls (Project 2 of JDFI Washington University Center for Islet Transplantation, KS Polonsky, PI)

If Islet Cell transplants are to become a reasonable treatment alternative for patients with type 1 diabetes, there must be knowledge about how the islet cells function after transplant {islet cells are responsible for making the insulin the body needs in order to control blood sugar). This knowledge would allow for improvements in the islet cell transplant procedure itself, as well as possible alterations of the immunosuppressive medications (drugs that prevent rejection) that are prescribed. There are two basic kinds of diabetes, type 1 (formally known as Insulin Dependent or Juvenile diabetes) and type 2 (formally known as Adult-Onset or Non-insulin dependent) diabetes. The patients in this study will be affected by type 1 diabetes. After the transplant, it is hoped they will no longer need insulin injections. It is possible patients may need to take pioglitazone and/or metformin, however, this will be prescribed in Project 1, if needed.

The medications used for this study include: C-peptide. This is a synthetic product (not from human or animal sources) that is man-made and identical to the C-peptide made by the body. C-peptide is made at the same time as insulin, one molecule of insulin equals one molecule C-peptide. By giving C-peptide that is synthetic, researchers can measure how the C-peptide breaks down in the body, which could then be related to how insulin breaks down in the body. Somatostatin will also be used during the same test as the C-peptide. While receiving Somatostatin, the production of insulin by the patient will be stopped. This medication will only be given for 4 hours and the blood sugar will be monitored during the entire procedure. Insulin & Glucose will also be given by IV during certain tests to regulate the blood sugar. Blood sugars will be maintained within a certain level and this will be achieved through the administration of insulin and/or glucose. The patient's blood sugar will be monitored at frequent intervals throughout the various procedures.