The oral glucose tolerance test

Diabetes Mellitus

There 2 types of diabetes mellitus:

Type 1 diabetes mellitus is a chronic (lifelong) disease that occurs when the pancreas produces too little insulin to regulate blood sugar levels appropriately.

Type 2 diabetes mellitus often called adult or non-insulin-dependent diabetes.

The following tests can be used to diagnose diabetes mellitus:

1. Urine analysis shows glucose and ketone bodies in the urine, but a blood test is required for diagnosis.
2. Fasting blood glucose is 126 mg/dl or higher.
3. Random (non fasting) blood glucose exceeds 200 mg/dl (this must be confirmed with a fasting test).
4. The oral glucose tolerance test: It is useful in certain cases.

Normal fasting blood glucose: 64 to 110 mg/dl

Note: mg/dl = milligrams per deciliter

Greater than normal levels (hyperglycemia) may indicate:

• Acromegaly (very rare).
• Cushing's syndrome (rare).
• Diabetes mellitus: fasting blood glucose of greater than 126 mg/dl.
• Impaired fasting glucose: 110 to 126 mg/dl a pre-diabetic state.
• Hyperthyroidism.
• Pancreatic cancer
• Pancreatitis
• Pheochromocytoma (very rare)
• Insufficient amount of insulin
• Excessive food intake

Lower than normal levels (hypoglycemia) may indicate:

• Hypopituitarism
• Hypothyroidism
• Insulinoma (very rare)
• Injection of too much insulin
• Insufficient dietary intake