Endocrine Abstracts

Reactive hypoglycaemia is usually mild, often presents with non-specific symptoms and may be difficult to distinguish from neuropsychiatric illnessThe diagnosis should be considered when these symptoms are related to eating. We present a severe case of idiopathic hypoglycaemia which responded dramatically to the alpha-glucosidase inhibitor acarbose.

A 25 year old woman presented with a nine year history of intermittent thirst, feeling hot, distal paraesthesiae and tiredness which had been gradually worsening. These symptoms developed about 2 to 3 hours after a meal and were relieved by carbohydrate in 15 to 20 minutes. She had started sweating profusely, shaking and talking incoherently, and was then incontinent of urine. Her only past history was an appendicectomy. Renal, liver, thyroid function and calcium were normal. Her fasting glucose was 2.7mmol/l (3.5-6.1mmol/l). Urinary adrenaline, noradrenaline and metabolites were normal on three occasions. An oral glucose tolerance test was performed and her glucose fell to 2.3 mmol/l at 210 minutes. After a 24 hour fast and exercise, plasma glucose was 2.4 mmol/l (.3.5-6.0mmol), c-peptide 564pmol/l (120-600 pmol/l, fasting range less than 600pmol/l), insulin 9.3mu/l. Urine screen for sulphonylurea abuse was negative. She was started on acarbose 50mg once a day, gradually increasing to three times a day and advised to eat frequent small meals. She has tolerated the treatment well and it has completely abolished her hypoglycaemic episodes enabling a normal life.

Discussion: Idiopathic reactive hypoglycaemia is a well documented entity but significant scepticism and even frank disbelief exists regarding its existence. Acarbose, a potent alpha-glucosidase inhibitor, reduces postprandial blood glucose increment and, thus, the insulin response. In contrast to most cases of reactive hypoglycaemia which are mild, our patient had a severe reactive hypoglycaemia which responded dramatically to acarbose treatment.