What is the estimated average glucose level during the last 2-3 months measured by?

The estimated average glucose level during the last 2-3 months is measured by the Hemoglobin A1c test. This test assesses the percentage of glucose that is attached to hemoglobin in the blood, providing an indication of average blood sugar levels over time. Essentially, it reflects the chronic exposure of red blood cells to glucose. The lifespan of red blood cells is approximately 120 days, which corresponds to the 2-3 months timeframe that the A1c test represents.

In contrast, the other options are not relevant measures for estimating average glucose levels over a prolonged period. For example, a Thyroid Function Test evaluates thyroid hormone levels, while a Lipid Panel measures cholesterol and triglyceride levels in the blood. The SED rate (Erythrocyte Sedimentation Rate) is a test that measures inflammation in the body, and does not provide information about glucose levels. Thus, the Hemoglobin A1c test is the appropriate choice for assessing glycemic control over the specified duration.