25 Jul
OGTT is useful for diagnosing diabetes, insulin resistance, impaired beta cell function, and sometimes reactive hypoglycemia and acromegaly, or rarer disorders of carbohydrate metabolism. For appropriate interpretation of this test, the patient must fast overnight and ingest a 75 g load of glucose in 100 mL of water. Immediately after, a fasting specimen is obtained, followed by collection at 1 hr, 2 hr and 3 hr.