1995 Volume 42 Issue 2 Pages 147-151
The mechanism(s) of an inappropriate secretion of insulin is poorly understood. We report a case of reactive hypoglycemia associated with an unusually exaggerated insulin secretion. The patient, a 32-year-old man, developed frequent episodes of postprandial hypoglycemia after interferon treatment was begun for chronic type C hepatitis. Oral glucose challenge test confirmed the patient's extremely high plasma IRI response, i.e., more than 1000μU/ml, and that of plasma C-peptide 56.9ng/ml at 90 min, followed by symptomatic hypoglycemia (plasma glucose 34mg/dl) at 240min. The plasma proinsulin level also was high, but the molar ratio of immuno reactive insulin (IRI)/plasma C-peptide and IRI/proinsulin was within the normal range. Antibodies to insulin or insulin-receptor were negative. Plasma IRI response was apparently greater when the glucose was given orally than when given intravenously. The response of plasma glucagon-like-peptide (GLP)-1 to oral glucose was quite high (from baseline of 45.5 to 303.2pmol/L) and showed a close parallel with the change in the plasma IRI concentration. The greatly enhanced insulin secretion leading to reactive hypoglycemia in this patient may therefor be attributed to the increased secretion of GLP-1.
