title: A case of hyperinsulinemia of undetermined origin, successfully treated with long-acting octreotide.
abstract: Major causes of fasting hypoglycemia in adults are insulinoma, factitious hypoglycemia and nesidioblastosis. The primary treatment for insulinoma is surgical removal of the tumor, but there are cases with hyperinsulinemia that cannot undergo surgery. Somatostatin analogue is one of the treatments used in such cases of insulinoma or persistent hyperinsulinemic hypoglycemia. We report here a patient who had undetermined hyperinsulinemia and was successfully treated with a long-acting somatostatin analogue, which had recently become available. The patient, a 72-year-old female, who had previously been diagnosed as insulinoma and undergone partial pancreatectomy, was admitted complaining of the recurrence of hypoglycemic attacks after an interval of ten years. On admission, hypoglycemia (42 mg/dl), hyperinsulinemia (IRI: 79.3 microU/m) and low HbA1c (3.6%) were present. In 75 g-OGTT at 30 min after load, IRI reached 6623 microU/ml, while plasma glucose level was 88 mg/dl. The anti-insulin antibody was not present. Since attempts at tumor localization by imaging techniques failed and the patient refused further examinations or surgical treatment, we recommended her to take a medication with a somatostatin analogue. Insulin suppression test using 50 microg of octreotide improved plasma glucose and IRI levels, suggesting the usefulness of the treatment, and a monthly administration of 20 mg of long-acting octreotide has successfully controlled her symptoms of hypoglycemia for 10 months. Our case demonstrated the utility of the long-acting somatostatin analogue for long-term treatment of undetermined hyperinsulinemia. A preliminary loading test using short-acting octreotide may be useful to determine appropriate medication, especially in cases who cannot receive surgical treatment.
authors.affiliation: Department of Metabolic Medicine, Graduate School of Medical Sciences, Kumamoto University, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kondo
authors.forename: Saori
authors.initials: S
authors.lastname: Tomita
authors.forename: Hironori
authors.initials: H
authors.lastname: Adachi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Motoshima
authors.forename: Kayo
authors.initials: K
authors.lastname: Taketa
authors.forename: Akiko
authors.initials: A
authors.lastname: Matsuyoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tokunaga
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Miyamura
authors.forename: Eiichi
authors.initials: E
authors.lastname: Araki
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D003692:Delayed-Action Preparations; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006946:Hyperinsulinism / Q000188:drug therapy*; D007328:Insulin / Q000097:blood; D015282:Octreotide / Q000008:administration & dosage*
chemical_list: D001786:Blood Glucose; D003692:Delayed-Action Preparations; D006442:Glycated Hemoglobin; D007328:Insulin; D015282:Octreotide