Fasting blood glucose Blood, serum, or plasma Children (> 2 years) - adult Whole blood: 60-110 mg/dl Plasma or serum: 70-120 mg/dl Elderly individuals: 80-150 mg/dl Children (< 2 years): 60-100 mg/dl Infant: 40-90 mg/dl Neonate: 30-60 mg/dl To diagnose and manage patients with Diabetes Mellitus Acromegaly Chronic pancreatitis Cushing's Syndrome Diabetes Mellitus Hyperthyroidism Pheochromocytoma Stress Addison's Disease Advanced liver disease Excessive exogenous insulin Islet cell adenoma Leucine sensitivity Malnutrition Noncompliance with fasting Vigorous exercise Stress Medications (acetaminophen, arginine, benzodiazepines, beta-blockers, epinephrine, ethacrynic acid, furosemide, glucocorticoids, glucose intake, hypoglycemic agents, insulin, lithium, MAO inhibitors, oral contraceptives, phenothiazines, phenytoin)