A1c as a Diagnostic Tool

Most people with diabetes should be familiar with the term A1c—a measure of the glycosylated hemoglobin in blood that gives an estimate of glycemic control over a period of several months. Hemoglobin is a protein found in your red blood cells that helps carry oxygen around your body (and gives blood its red color). As red blood cells circulate, glucose present in the blood will stick to your red blood cells (a process called glycation). A1c testing is nothing new, but experts have begun thinking about using A1c as a way of diagnosing type 2 diabetes, something that until now could only be done with more difficult tests to measure fasting glucose (when a person has not eaten for eight hours or more) and post-prandial glucose (the glucose value after a meal). The argument for using A1c is that it’s easier for patients, because it requires only one blood sample, and won’t change depending on what people eat or do in the days leading up to the test. If you already have diabetes, this isn’t going to change your management. Experts at ADA set 6.5% or higher as the treshold for diagnosing diabetes. If you know someone at risk of diabetes, encourage them to ask their doctor about an A1c test.