August 22, 2021

What You Need To Know About HbA1c

Anyone with diabetes has most likely had an HbA1c test at some point.  You may not even realize what that is, other than looking at it on your lab values from your blood work report.  This test has been one of the gold standards for measuring how well diabetes is controlled.  The test is generally performed every 3-4 months, and it reflects an average blood glucose over that period of time.

Your health care team will decide what your HbA1c goal should be.  If your HbA1c is above your target value, and your fasting blood sugars are on point, this means that you probably have higher than normal after meal blood glucose readings.  The HbA1c can prevent you from coming to an incorrect conclusion about your diabetes control.  Some people only test blood sugars in the morning after fasting; this doesn’t provide the whole picture as to how well your diabetes is being controlled.

Diabetes treatment is often decided upon by looking at HbA1c values.  For example, according to the newest American Diabetes Association guidelines, an elevated HbA1c in a newly diagnosed type 2 patient indicates that basal insulin should be considered as part of that person’s treatment.1

Keep in mind that unlike a few home blood sugar values, the HbA1c test reflects long term glycemic control.  Newly diagnosed patients, for example, that present to the doctor’s office with an HbA1c or 9 or 10 probably have had type 2 diabetes for a long period of time without symptoms.  In contrast, if a patient has an HbA1c test that is very low, it may indicate that that patient has been having frequent low blood sugars.2  It is important to stay in good control, while avoiding excessive hypoglycemia that can also be dangerous.  Staying within the navigational beacons to keep diabetes in control is challenging, but achievable.

Bringing down a clinically elevated HbA1c to an acceptable level can significantly reduce the possibility of diabetes complications.In general, your provider will give you an HbA1c test four times a year if you are not at goal, or yearly if you seem to be doing well.  This is for type 2 diabetes, as someone with type 1 diabetes may need more frequent testing because of their total dependence on insulin therapy.  Below is a conversion chart that may help you understand your HbA1c a little better. 4

 Correlation of HbA1c with Estimated Average Blood Glucose

HbA1c                      mg/dl                      mmol/l

6                                 126                        7.0

7                                 154                        8.6

8                                 183                       10.2

9                                  212                       11.8

10                                240                       13.4


About Susan Sloane
Susan B. Sloane, BS, RPh, CDE, has been a registered pharmacist for more than 29 years and a Certified Diabetes Educator for most of her career. Her two sons were diagnosed with diabetes, and since then, she has been dedicated to promoting wellness and optimal outcomes as a patient advocate, information expert, educator, and corporate partner.

Susan has published numerous articles on the topic of diabetes for patients and health care professionals. She has committed her career goals to helping patients with diabetes stay well through education.

Medical Disclaimer
The articles provided on this website are for informational purposes only. In addition, it is written for a generic audience and not a specific case; therefore, this information should not be used for diagnostic or medical treatment. This site does not attempt to replace the patient-physician relationship and fully recommends the reader to seek out the best care from his/her physician and/or diabetes educator.

1.American Diabetes Association. Approaches to glycemic treatment. Sec. 7. In: Standards of Medical Care in Diabetes – 2016. Diabetes Care. 2016;39(Suppl. 1):S52–S59.

2.Gerstein HC, Miller ME, Byington RP, et al; Action to Control Cardiovascular Risk in Diabetes Study Group. Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med. 2008;358(24):2545-2559.

3.Albers JW, Herman WH, Pop-Busui R, et al; Diabetes Control and Complications Trial/ Epidemiology of Diabetes Interventions and Complications Research Group. Effect of prior intensive insulin treatment during the Diabetes Control and Complications Trial (DCCT) on peripheral neuropathy in type 1 diabetes during the Epidemiology of Diabetes Interventions and Complications (EDIC) study. Diabetes Care. 2010;33(5):1090-1096.

4.Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ; A1c-Derived Average Glucose Study Group. Translating the A1C assay into estimated average glucose values. Diabetes Care. 2008;31(8):1473-1478.

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