Are Abnormalities in Insulin Secretion Responsible for Reactive Hypoglycemia?

Seventy patients with reactive hypoglycemia strictly defined by criteria which interpret the low blood glucose value in relationship to clinical and physiologic parameters, were studied to determine if abnormalities in insulin secretion could be demonstrated. These patients were separated into four groups: alimentary (N = 5), diabetic (N = 16), hormonal (N = 5), and idiopathic (N = 44). The findings in these patients were compared to normal control subjects and to weight- and disease-matched patient controls. All of the patients with hormonal and most patients with idiopathic reactive hypoglycemia (thirty-two of forty-four) demonstrated delayed insulin secretion regardless of the control group used for comparison. Diabetic reactive hypoglycemic patients exhibited delayed insulin secretion when compared to normal controls but not when compared to weight-matched diabetic controls. Excessive insulin secretion was consistently found only in the patients with the alimentary variety of reactive hypoglycemia. Using weight- and diseasematched control groups, no abnormalities in insulin secretion could be found to account for the hypoglycemia in the diabetic reactive hypoglycemic patients and some idiopathic reactive hypoglycemic (nine of forty-four) patients. These results help to explain the inconsistent findings of previous investigators and suggest that reactive hypoglycemia is a syndrome having multiple etiologies.