Insulin response to carbohydrate ingestion after gastric surgery with special reference to hypoglycaemia.

Factors responsible for spontaneous hypoglycaemia were investigated in 23 gastrectomy patients and two patients with vagotomy and pyloroplasty. Plasma insulin and capillary blood glucose levels were followed after giving 175 ml of 50% glucose orally. In gastrectomy patients a significant correlation was found between the height of the peak blood glucose and insulin levels for the same individual. Patients with high peak glucose and insulin levels were significantly more likely to develop hypoglycaemia later in the test. These findings are compatible with the suggestion that the major factor predisposing to hypoglycaemia is a faster than average rate of emptying of the gastric remnant, but this does not explain all the results. In two cases, hypoglycaemia followed an abnormally large insulin response to oral glucose. The results of insulin injection tests in 14 patients do not exclude the further possibility that in some cases hypoglycaemia is due to excessive insulin sensitivity.