a test for diabetes, or for hypoglycemic states such as may be seen, rarely, in patients with insulinomas. Following ingestion of 75-g glucose while the patient is fasting, the blood sugar promptly rises and then falls to normal within 2 hours; in diabetic patients, the increase is greater and the return to normal unusually prolonged; in hypoglycemic patients, depressed glucose levels may be observed in 3-, 4-, or 5-hour measurements.