What is A1C?
The A1C test indicates blood sugar control over the last 2-3 months. A1C is also known as glycated hemoglobin or glycosylated hemoglobin.

A1C values are directly proportional to the concentration of glucose in the blood over the full lifespan of the red blood cells (90-120 days). A1C values are not subject to the fluctuations that are seen with daily blood glucose monitoring.

ADA Guidelines
The American Diabetes Association (ADA) guidelines call for intensive management of type 1 and 2 diabetics to control hyperglycemia and minimize the risk of complications.

The ADA recommends A1C as the best test to find out if a patient's blood sugar is under control over time. The test should be performed every 3 months for insulin-treated patients, during treatment changes, or when blood glucose is elevated. For stable patients on oral agents, the recommended frequency is at least twice per year. According to the ADA, the target A1C value is <7%. Patients with values >8% require reevaluation.