Background: Insulin antibody (IAb) may be produced in patients receiving long-term, animal-derived insulin, leading to insulin resistance or hypoglycemia. There have been very few reports of hypoglycemia caused by IAb in patients taking recombinant human insulin.
Case report: We report the case of an 82-year-old male patient with type 2 diabetes mellitus who suffered repeated episodes of severe hypoglycemia-related symptoms (including coma) prior to admission. The patient had been taking Novolin 30R, a premixed human insulin. The patient's IAb level was markedly elevated, and hypoglycemia caused by recombinant human insulin treatment-induced IAb production was diagnosed. Acarbose and metformin were prescribed, and the patient recovered uneventfully. The patient ceased taking these medications, and he was subsequently treated with recombinant human insulin to combat hyperglycemia. This was followed by reoccurrence of hypoglycemic coma. The patient was advised to avoid taking recombinant human insulin for the rest of his life and to control hyperglycemia with acarbose and metformin.
Conclusions: Although rare, hypoglycemia caused by recombinant human insulin-induced IAb production should be considered in patients with type 2 diabetes who experience repeated episodes of hypoglycemia.