title: Late postprandial hypoglycemia due to bioactive insulin dissociation from autoantibody leading to unconsciousness in a patient with insulin autoimmune syndrome.
abstract: We report here the case of an 83-year-old man who was treated for unconsciousness and hypoglycemia (39 mg/dL) accompanied by marked elevation of serum immunoreactive insulin (IRI) (4,760 µIU/mL). We diagnosed his condition as insulin autoimmune syndrome (IAS, Hirata disease) because of a high insulin autoantibody (IAA) titer (>90%: bound/total) and no history of exogenous insulin administration. Reactive hypoglycemia occurred due to immediate association followed by dissociation between insulin and insulin autoantibodies after glucose or food intake. An α-glucosidase inhibitor in combination with frequent small meals reduced the postprandial hyperglycemia (glucose spike) and ameliorated the reactive hypoglycemia.
authors.affiliation: Department of Internal Medicine, Naga Municipal Hospital, Japan. t.nasu@nagahp.jp
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Nasu
authors.forename: Ryoko
authors.initials: R
authors.lastname: Suzuki
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Kaori
authors.initials: K
authors.lastname: Miyata
authors.forename: Akiko
authors.initials: A
authors.lastname: Uno
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Nakao
authors.forename: Akira
authors.initials: A
authors.lastname: Kawashima
authors.forename: Taisei
authors.initials: T
authors.lastname: Nakao
authors.forename: Michi
authors.initials: M
authors.lastname: Kondo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000937:Antigen-Antibody Reactions / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000097:blood / Q000150:complications* / Q000276:immunology; D001786:Blood Glucose; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000209:etiology* / Q000276:immunology*; D007328:Insulin / Q000097:blood* / Q000276:immunology*; D007330:Insulin Antibodies / Q000097:blood*; D007700:Kinetics; D008297:Male; D019518:Postprandial Period; D013577:Syndrome; D014474:Unconsciousness / Q000097:blood / Q000209:etiology / Q000276:immunology
chemical_list: D001323:Autoantibodies; D001786:Blood Glucose; D007328:Insulin; D007330:Insulin Antibodies; D005947:Glucose