Recurrent hypoglycaemia caused by the insulin autoimmune syndrome: the first Dutch case

The insulin autoimmune syndrome is extremely rare outside of Japan. We describe a 45-year-old Caucasian woman who presented with fasting hypoglycaemia and weight gain. The presence of fasting insulin concentrations in excess of 1000 mU/l, very low C-peptide concentrations during hypoglycaemic attacks and high titres of insulin autoantibodies led to the diagnosis. Treatments aimed at decreasing endogenous insulin secretion by either dietary intervention alone or in combination with acarbose, octreotide or diazoxide had only limited success, while a 2-week course of immunosuppression with prednisone was without any antihypoglycaemic effect.