Insulin Mimicking Mystery: Decoding Recurrent Hypoglycemia

Abstract

Abstract Insulin antibody syndrome (IAS), also known as Hirata disease, is a rare condition characterized by spontaneous hypoglycemic episodes unrelated to exogenous insulin exposure. It is caused by elevated serum levels of insulin autoantibodies (IAA). IAS typically occurs when a triggering factor, such as medication or viral infection, interacts with a predisposing genetic background. Diagnosing IAS is challenging due to its rarity and the presence of multiple potential causes for hyperinsulinemic hypoglycemia. The presence of Whipple triad—symptoms of hypoglycemia, low plasma glucose concentration, and relief of symptoms after raising plasma glucose—strongly supports the diagnosis of IAS. However, the detection of IAA is considered the most reliable test. Timely diagnosis can facilitate appropriate treatment and prevent unnecessary imaging studies and invasive procedures, thereby reducing costs. Currently, no definitive guidelines exist for managing IAS. Most management strategies involve supportive measures due to the high rate of spontaneous remission, with hypoglycemia often managed through dietary interventions. However, a few medications have shown benefit. Although predominantly observed in the Japanese population, IAS cases have been reported in other ethnicities, including Caucasians. This report presents a unique case of IAS in an African American male.