In mild diabetes, postprandial hyperglycemia persists despite excessive plasma insulin concentrations. This phenomenon could result either from blunted beta cell responsiveness or from peripheral blockade of insulin action. In the present study, maximal insulin secretion after sudden glucose challenge was greater and occurred six times faster in 18 normal subjects than in 10 mild diabetics. During paired oral and intravenous glucose tolerance tests, blood glucose (Somogyi), and plasma insulin (immunoassay) were determined at 5, 10, 20, 30 min, then half-hourly.
Oral Glucose Tolerance Tests: In normals, blood glucose peaked at 30 min (112 ± 4 mg per 100 ml, mean