A1C and diabetes

The A1C test is a common blood test used to diagnose Type 1 and Type 2 diabetes and to monitor how well you’re managing your diabetes. It reflects your average blood sugar level for the past two or three months.

Specifically, it measures what percentage of your hemoglobin – a protein in red blood cells that carries oxygen – is coated with sugar. The higher your A1C level, the poorer your blood sugar control and the higher your risk of diabetes complications.

The results can help your doctor:

• Identify prediabetes, which may lead to a higher risk of developing diabetes and cardiovascular disease;
• Diagnose Type 1 and Type 2 diabetes; and
• Monitor your diabetes treatment plan and adjust your diabetes medicine if necessary.

The A1C test is a simple blood test done in your doctor’s office or a lab. You don’t need to fast so you can eat and drink normally before taking it. How often you should take the test depends on the type of diabetes you have, your treatment plan and how well you’re managing your blood sugar.

A1C testing is recommended:

• Once a year if you have prediabetes;
• Twice a year if you have type 2 diabetes, you don’t use insulin and your blood sugar level is consistently within your target range; or
• Every three months if you have type 2 diabetes, or if you have type 2 diabetes and you use insulin or you have trouble keeping your blood sugar level within your target range.

The test results are reported as a percentage. A higher percentage means higher average blood sugar levels. Higher levels increase your risk of developing diabetes or complications of diabetes, such as cardiovascular or kidney disease. 

• Normal level: Below 5.7%
• Prediabetes: Between 5.7% and 6.4%
• Diabetes: 6.5% or higher; for most adults with diabetes 7% or less is a common treatment target

It’s a good idea to get a baseline A1C test if you’re age 45 or older, or if you’re under age 45 and are overweight or have risk factors.

Prediabetes and type 2 risk factors

• Age 45 or older
• Overweight
• Parent, brother or sister with type 2 diabetes
• Physically active less than three times a week
• Have had gestational diabetes (diabetes during pregnancy)
• Are of African, Mediterranean or Southeast Asian descent

Type 1 risk factors

• Family history
• Age (more likely to develop when you’re a child, teen or young adult)

If you have diabetes, A1C is an important tool for managing diabetes but it doesn’t replace regular blood sugar testing at home. Blood sugar goes up and down throughout the day. If you’re reaching your A1C goal but having symptoms of high or low blood sugar, check your blood sugar often and at different times of the day.

A combination of diet, exercise and medication can bring your levels down. Work closely with your doctor in managing your blood sugar level long-term.

Sources:
“All About Your A1C.” www.cdc.gov, Centers for Disease Control and Prevention, 21 August 2018.
“Who’s at Risk?” www.cdc.gov, Centers for Disease Control and Prevention, 30 May 2019.
“A1C Test.” www.mayoclinic.org. Mayo Foundation for Medical Education and Research (MFMER), 18 December 2018.
“Hemoglobin A1c (HbA1c) Test for Diabetes.” www.webmd.com, WebMD, LLC, 1 November 2018.