Insulin autoimmune syndrome (IAS) is a disease characterized by hyperinsulinemic hypoglycemia associated with autoantibodies against endogenous insulin. A 56-year-old man was admitted to Ningbo First Hospital for the treatment of spontaneous hypoglycemia. He was found to have elevated fasting insulin level (>1,000 mIU/l) and presence of insulin autoantibodies, and after appropriate workup, was diagnosed with IAS. After treating with prednisone for 2 months, his insulin level started decreasing. In patients with repeated hypoglycemia, IAS should be considered in the differential diagnosis. Prednisone may be effective for the treatment of hypoglycemia in patients with IAS.
Keywords: continuous glucose monitoring system; insulin autoantibodies; insulin autoimmune syndrome.