Hemoglobin A1c (HbA1c) Test for Diabetes

What is a Hemoglobin A1c (Average Blood Sugar) Test?

The Hemoglobin A1C Test  is also called HbA1c, glycated hemoglobin test, or glycoslated hemoglobin test is a common blood test used to diagnose type 1 and type 2 diabetes to determine how well your diabetes is being controlled. 

According to American Diabetes Association, the test result of A1c reflects your average blood sugar level for the past two to three months. Specifically, the A1C test measures what percentage of your hemoglobin (a protein in red blood cells that carries oxygen) is coated with sugar (glycated). The higher your A1C level, the poorer your blood sugar control and the higher your risk of diabetes complications. 

Why Hemoglobin A1c Test  is Done?

Based on the international committee of experts from the European Association for the Study of Diabetes, American Diabetes Association, and International Diabetes Federation stated that they recommends the A1C test as the primary test used to diagnose prediabetes, type 1 diabetes and type 2 diabetes.

A1C test can help you manage your diabetes:
  • to determine if your treatment plan is working properly
  • to confirm self-testing results or blood test results by the doctor.
  • to show you how healthy choices can make a difference in diabetes.
How to Prepare A1c Test?

A1c Test is a quite simple blood test. You just eat and drink normally before the test.

Expect your the A1c test

During the test, the health care team practitioner simply takes a sample of blood by inserting a needle into a vein in your arm or pricking the tip of your finger with a small, pointed lancet. The blood sample is sent to a lab for analysis. You can return to your usual activities immediately.

The Results

After the blood analysis, the results conclude for someone who doesn't have diabetes, a normal A1C level can range from 4.5 to 6 percent. Someone who's had uncontrolled diabetes for a long time might have an A1C level above 8 percent.

When the A1C test is used to diagnose diabetes, an A1C level of 6.5 percent or higher on two separate tests indicates you have diabetes. A result between 5.7 and 6.4 percent is considered prediabetes, which indicates a high risk of developing diabetes.

For most people who have previously diagnosed diabetes, an A1C level of 7 percent or less is a common treatment target. Higher targets may be chosen in some individuals. If your A1C level is above your target, your doctor may recommend a change in your diabetes treatment plan. Remember, the higher your A1C level, the higher your risk of diabetes complications.

Here's how A1C level corresponds to average blood sugar level, in milligrams per deciliter (mg/dL) and millimoles per liter (mmol/L):

A1C level        Estimated average blood sugar level
5 percent        97 mg/dL (5.4 mmol/L)
6 percent        126 mg/dL (7 mmol/L)
7 percent        154 mg/dL (8.5 mmol/L)
8 percent        183 mg/dL (10.2 mmol/L)
9 percent        212 mg/dL (11.8 mmol/L)
10 percent        240 mg/dL (13.3 mmol/L)
11 percent        269 mg/dL (14.9 mmol/L)
12 percent        298 mg/dL (16.5 mmol/L)
13 percent        326 mg/dL (18.1 mmol/L)
14 percent        355 mg/dL (19.7 mmol/L)

What are the limitations?

Although the A1C test is an important tool, it can't replace daily self-testing of blood glucose for those who need it. A1C tests don't measure your day-to-day control. You can't adjust your insulin on the basis of your A1C tests. That's why your blood sugar checks and your log of results are so important to staying in effective control.






Source & References:
    1. A1c Test - mayoclinic.com Retrieved last March 3, 2013
    2. Living with Diabetes  - diabetes.org. Retrieved last March 3, 2013 
    3. The Hemoglobin A1c (HbA1c) Test for Diabetes - webmd.com Retrieved last March 3, 2013 
    4. Image source: http://www.dlife.com/diabetes/export/pics/dLife_Images/A1C_Levels_p1.jpg. Retrieved last March 3, 2013