What is a common laboratory test used for the detection of diabetes?

Hemoglobin A1c is a widely used laboratory test for the detection and monitoring of diabetes, as it measures the average blood glucose levels over the past two to three months. This test provides insight into how well diabetes is being managed over time, as it reflects the amount of glucose that has been attached to hemoglobin molecules in red blood cells. High levels of Hemoglobin A1c indicate poor blood sugar control and a higher risk of diabetes-related complications.

While the other options can provide useful information related to general health and other conditions, they do not specifically assess glucose levels or diagnose diabetes. For instance, a complete blood count evaluates overall health and can indicate various disorders, but it does not focus on glucose metabolism. Urinalysis might reveal glucose in the urine and could suggest diabetes, but it is not as definitive as the Hemoglobin A1c test. A thyroid function test primarily assesses thyroid hormones and is not relevant to the diagnosis of diabetes. This makes Hemoglobin A1c the most appropriate and commonly used test for detecting and managing diabetes.