2009 Volume 52 Issue 6 Pages 449-455
We report a case of insulin autoimmune syndrome showing marked hyperinsulinemia with no autoimmune disease background or SH-group drug history. A 28-year-old woman working as a nurse and experiencing hidropoiesis, palpitations, and hand and finger tremors self-medicated for her hypoglycemia by eating candy and drinking soft drinks. Hypoglycemic recurrence, a blood glucose level of 59 mg/dl, and an immunoreactive insulin (IRI) level of 4,600 μU/ml confirmed marked hyperinsulinemia. Insulin autoimmune syndrome was diagnosed based on the absence of an insulin injection history, an insulin antibody level of 97%, and Scatchard analysis [results of k=0.12 (108 l/mol), b=21.8 (10-8 mol/l)]. Hypoglycemic attacks recurred mainly at night and three hours after meals, but the woman's condition improved with smaller, more frequent meals and α-glucosidase inhibitor administration. Over time her, hypoglycemia declined, and spontaneous remission was confirmed for both IRI and insulin antibodies. Although positive results were obtained in this case for insulin receptor antibody, we believe this was a false positive result due to marked hyperinsulinemia.
