Radioactive Iodine Therapy and Glucose Tolerance

Radioactive iodine therapy is commonly used as an adjuvant therapy in follicular and papillary thyroid carcinoma (PTC) and in the treatment of Graves' disease (GD). The basis of this therapy is the accumulation of radioactive iodine by the sodium-iodide symporter (NIS) in the thyroid gland. Expression of NIS by extrathyroidal tissues such as islets of pancreas has been reported. Radioactive iodine uptake by pancreatic beta-cells can potentially damage these cells. In this study, we discuss the possible associations between radioactive iodine and glucose intolerance. Overall, radioactive iodine uptake by the pancreas may damage beta-cells and predispose patients to glucose intolerance or type 2 diabetes, particularly in patients exposed to radioactive iodine therapy following total thyroidectomy. Further studies are needed to clarify and confirm this association.