Abstract
Introduction: Recurrent symptomatic hyperinsulinaemic hypoglyca- emia has been increasingly recognised following Roux-en-Y gastric bypass (RYGB), is disabling and potentially dangerous to others. Dietary manipulation is frequently unsuccessful and patients have undergone surgical revision, restoration of gastric restriction, or par- tial pancreatectomy. Methods: Four patients with symptoms of post-prandial hypoglyca- emia following RYGB were evaluated. Patients underwent an extended oral glucose tolerance test (OGTT) receiving 75 g oral glu- cose with blood taken for insulin and glucose assays each 30 minutes for 240 minutes. The investigation was repeated after pre-adminis- tration of octreotide (100 mcg subcutaneous). Results: Patients were 40.3 ± 19.6 years old and between 1.5 and 7 years postoperative. Preoperative weight was 132.5 ± 14.4 kg, cur- rent weight 85.5 ± 24.6 kg. Glucose and insulin data from extended OGTT (mean ± SEM).are shown below. Symptomatic hypoglyca- emia occurred in all subjects at 150 minute. Peak insulin excursion at 60 minute was almost eliminated after octreotide administration. Conclusion: Reactive hypoglycaemia after RYGB can be provoked by an extended OGTT. Octreotide inhibits insulin release and in this study prevented hypoglycaemia after a single administration. It remains to be determined whether extended use might be of use in symptomatic patients.