What is the most reliable test for monitoring glucose levels and why is it preferred?

The A1C test is the most reliable test for monitoring glucose levels because it provides an average of a person's blood glucose levels over a longer period—typically the past two to three months. This longer timeframe helps minimize variability that can be present with other methods, such as fasting blood glucose measurements, which can be influenced by various factors including recent meals, stress, or illness.

The A1C test reflects overall glycemic control and is particularly useful for assessing how well diabetes is managed over time, allowing healthcare providers to make informed decisions regarding treatment adjustments. Its standardization across laboratories also contributes to its reliability, making the A1C test a preferred option in both clinical practice and research settings for monitoring long-term glucose control. Additionally, its ability to correlate with the risk of diabetes-related complications emphasizes its importance in patient management.