Metabolic Sequelae of Pancreas Transplantation

Pancreas transplantation, when it is successful, achieves normal levels of fasting glucose and glycosylated hemoglobin (HbA_1c) in recipients with type I (insulin-dependent) diabetes mellitus. However, many issues remain regarding the merits of this operative procedure. These issues include portal versus systemic pancreatic venous return, exocrine pancreas obstruction versus exocrine drainage of the allograft, metabolic consequences for donors of pancreas segments, criteria of effective hormonal secretion from fetal pancreas pieces and isolated islets, and adverse metabolic effects of immunosuppressive drugs. The future needs and directions of this research area include determination of the cause of excessive insulin levels and abnormal counterregulation of hypoglycemia in allograft recipients. Additionally, pancreatic polypeptide and somatostatin secretion are yet to be characterized. Finally, the long-term consequences of hemipancreatectomy in living related donors need to be established; specifically, whether donors are at increased risk for developing diabetes mellitus needs to be ascertained.