Postprandial Hyperinsulinemic Hypoglycaemia with Positive Selective Calcium Stimulation Test: a case of Idiopathic Reactive Hypoglycaemia.

Abstract

We report a 48 yo woman admitted for loss of consciousness with a glycaemia of 1.8. Past medical history included vagotomy and Bilroth I procedure for refractory ulcer. BMI was 20. History revealed repetitive postprandial neuroglycopenic symptoms ongoing for several years, with recent syncope. Patient denied alcohol consumption. Several episodes of postprandial hypoglycaemia with hyperinsulinism occurred during hospitalisation, with the lowest two hour postprandial level of 1.9 mmol/L with high insulin 74 pmol/L and C-peptide 1.13 nmol/L values. The venous glycaemia after a forty hour fast was 3,0 mmol/L with low insulin of 2,8 pmol/L. Sulfonylurea screen was negative. Peak Cortisol after cosyntropin stimulation reached 721 nmol/L. Anti-insulin antibodies were negative. An OGTT and nuclear gastric emptying test were normal. Ct scan of the abdomen and endoscopic ultrasonography of the pancreas were normal. Because of the hyperinsulinism, selective intraarterial pancreatic stimulation test was done. Calcium gluconate was injected sequentially in the hepatic, gastroduodenal, superior mesenteric and splenic arteries with measurement of insulin in the hepatic vein between 0 and 120 seconds: strong insulin stimulation was observed only with the splenic artery test, with insulin rising from 12,2 at 0 seconds to 193,2 pmol/L at 60 seconds. Although diazoxide prevented major hypoglycemias, it caused oedema and hirsutism. Partial pancreatectomy of body and tail revealed to be curative with improved quality of life. Pathology report was normal, confirming the idiopathic reactive hypoglycaemia. Long term follow-up will be needed to screen for diabetes or recurrence of hypoglycaemia.