Long-term effect of alpha-glucosidase inhibitor on late dumping syndrome

Dumping syndrome commonly occurs after gastrectomy. The late dumping, which is one of the dumping syndromes, is due to postprandial hypoglycaemia caused by an excessive insulin secretion after a sharp rise in plasma glucose. Several treatments, including operation, dietary fibre and somatostatin, have been attempted to relieve dumping symptoms. These treatments take effect through modulation of plasma insulin and glucose levels, but their efficacy is still under consideration. Alpha-glucosidase inhibitor attenuates the postprandial increase of plasma glucose levels and is widely used for treatment of non-insulin-dependent diabetes mellitus (NIDDM). The acute effect of alpha-glucosidase inhibitor on late dumping syndrome has been reported by some studies with test meals. The purpose of this study was to evaluate a long-term effect of alpha-glucosidase inhibitor treatment with ordinary meals in late dumping patients with NIDDM because administration of alpha-glucosidase inhibitor is only ethically allowed for diabetic patients in Japan. Six late dumping patients with NIDDM were orally administered alpha-glucosidase inhibitor, acarbose (50 or 100 mg), three times a day before each meal for 1 month. Diurnal changes of plasma glucose, insulin and pancreatic glucagon levels were compared before and after the alpha-glucosidase inhibitor treatment. All patients had late dumping-related symptoms, such as weakness, palpitation and dizziness before the induction of alpha-glucosidase inhibitor treatment. Patients suffered from a rapid fall in plasma glucose levels from hyperglycaemia at the same time as dumping symptoms. These late dumping-related symptoms disappeared and a rapid change of plasma glucose and insulin levels were attenuated after the alpha-glucosidase inhibitor treatment. These data suggest a long-term therapeutic efficacy of alpha-glucosidase inhibitor for late dumping patients.