Advance with MUSC Health

Your A1C: What the Numbers Mean

Advance With MUSC Health
July 12, 2021
A hand taking an A1C test to measure blood sugar level.

We see the ads on TV, in print and online: Knowing our A1C is important for our health, especially if we’re at risk for developing diabetes or are one of the 34.2 million Americans who have been diagnosed with the condition. Still, understanding what A1C is, how to have a healthy A1C and what the numbers mean can be baffling. We talked with Dr. Ashley Hicks, a board-certified family medicine physician at MUSC Health Primary Care in Florence to find out what an A1C test measures, how it differs from a simple glucose tolerance test and why A1C matters. Dr. Hicks is also on the staff at MUSC Health Florence Medical Center.

Q. What is A1C?

A. The A1C test measures our blood sugar level. Specifically, it measures the amount of glucose that attaches itself to the hemoglobin in red blood cells. The more sugar we have in the blood, the higher the A1C. The A1C test is used to diagnose prediabetes, as well as Type 1 and Type 2 diabetes. The A1C test is also called the glycated hemoglobin, glycosylated hemoglobin, hemoglobin A1C or HbA1c test.

Q. How is A1C measured?

A. The A1C test can be done in two ways, both of which are simple and painless. We draw a vial of blood from the vein and send it to the lab, which takes a couple of days for results. Or we can do a point-of-care test, which involves pricking your finger and running the blood through an automated machine. This process takes a couple of minutes.

Q. Who should have an A1C test?

A. Technically, A1C can be measured in anybody, but we usually test to diagnose and monitor individuals who are diagnosed with Type 1 and Type 2 diabetes, as well as patients who are at risk for diabetes or becoming prediabetic, particularly obese individuals with a Body Mass Index over 30.

Q. How does it differ from the glucose tolerance test?

A. A1C measures blood sugar levels over the last three months. A glucose tolerance test shows only what your sugar level is the day you're tested, which reflects someone's food intake 24 to 48 hours before the test. Technically, both are accurate, but the glucose tolerance test requires a patient to fast before the test, so A1C is more convenient.

Q. What do the numbers mean?

A. A normal A1C is 5.6 or below. A prediabetic number is 5.7-6.4, and above 6.5 means you have diabetes. The medical community is debating whether to raise the acceptable number to a maximum of 8 in older adults.

Q. Does A1C tell me what type of diabetes I have?

A. No. It just measures the sugar in your blood.

Q. What are symptoms of a higher-than-normal A1C?

A. Prediabetes does not have any symptoms. People can be prediabetic and not know it, and these individuals are more prone to developing Type 2 diabetes, which often occurs in individuals who are obese and are physically inactive. Symptoms of Type I diabetes, as well as Type 2 diabetes, can include excessive urination and thirst and blurry vision.

Q. How often should I have an A1C test?

A. If your A1C is above normal, it should be checked every 3 months. If your diabetes is controlled, you can be tested every 6 months.

Q. What if I’m healthy and not obese? Do I need to be tested? Is an A1C test administered as part of a routine physical?

A. If you have risk factors such as a significant family history or symptoms, your doctor may recommend screening.

Q. How is A1C lowered?

A. A1C can be lowered through lifestyle changes and medications. Medications can be used to treat prediabetes, but most of the time I work with my patients to make major lifestyle changes, such as diet and exercise. I have patients who have successfully turned their lives around and lowered their A1C through a low-carbohydrate, low-sugar diet and exercise. Metformin is an old medication that is typically prescribed. If it is not effective, then we increase the dose and sometimes add other therapies, including newer oral medications and injections, which are easy and painless.

Q. What causes a high A1C?

A. Our pancreas produces insulin, which is essential to breaking down sugars and transferring them to red blood cells. Individuals whose pancreas doesn't produce enough insulin are prone to Type 1, which can occur in children and adults of younger age. Type 2 diabetes occurs when the pancreas is overworked and can't produce enough insulin to process the excessive intake of carbohydrates and sugars. The pancreas gives out. Both types can have a genetic component.

Q. Can someone who is on medication eventually get off the medication?

A. Yes, with aggressive lifestyle changes. Diet is the key because 75 percent of weight loss is the result of dieting, but it must be accompanied with exercise. I always recommend to my patients that they can successfully turn their lives around, and when they do, it makes such a difference. That is the good news.

Dr. Ashley Hicks is a board-certified family medicine physician who practices at MUSC Health Primary Care in Florence. For an appointment, call 843-679-4214.