Insulin Serum or plasma Fasting Adult: 5-25 uU/ml Newborn: 3-20 uU/ml 1 hour after eating: 50-130 uU/ml 2 hour after eating: < 30 uU/ml To assess for insulin producing tumors To confirm suspected insulin-resistant states Acromegaly Cushing's Syndrome Hyperinsulinism Liver disease Pancreatic lesions Vagal stimulation IDDM Hypopituitarism Noncompliance with test protocol Insulin antibodies Medications (ACTH, catecholamines, colchicine, diazoxide, oral contraceptives, phenytoin, steroids, sulfonylurea, thyroid hormones, vinblastine)