We are hereby reporting a case of a 72-year-old Indian man, who, in the absence of a detectable tumor, presented with symptomatic hypoglycemia in the postabsorptive state (3-5 h after meal). His serum levels of insulin and C-peptide were very high. He was not taking any hypoglycemic drug. Hypoglycemic episodes completely subsided after withdrawal of pentoprazole and incorporation of small frequent meals in the dietary plan. Six months after the initial presentation, the subject became free of hypoglycemic episodes. Although insulin autoimmune syndrome (IAS) is the third leading cause of spontaneous hypoglycemia in Japan, it is extremely uncommon in the Western Countries. Till 2009, more than 200 cases from Japan and as many as 58 cases outside Asia have been reported. To the best of our knowledge, this is the first case of IAS reported from India.
Keywords: Autoimmune hypoglycemia; Hirata's disease; insulin autoimmune syndrome.