Hemoglobin A1c (HbA1c) Test

 

Hemoglobin A1c (HbA1c) Test

Hemoglobin A1c test tells the average level of blood sugar over the past 2 to 3 months. It is also called HbA1c or glycated hemoglobin test.

People who have diabetes need this test regularly to see if their levels are staying within range. So, it can tell if the diabetic patients need to adjust their antidiabetic medicines. The HbA1c test is also used to diagnose diabetes except for gestational diabetes.

How the test works?

Hemoglobin is a protein found in red blood cells (RBC). The sugar in the blood is called glucose. When glucose builds up in the blood, it binds to the hemoglobin in the

RBC. The HbA1c test measures how much glucose is bound. Red blood cells live for about 3 months, so the test shows the average level of glucose in the blood for the past 3 months but it does not reflect daily ups and downs of blood glucose.

If the glucose levels have been high over recent weeks, the HbA1c test will be higher.

HbA1c is not affected by short-term fluctuations in blood glucose levels, so blood can be drawn for this test without regard to when food was eaten. Fasting is not necessary for this test.HbA1c levels

INDICATION

4.0 to less than 5.7%

Normal

5.7 - 6.4%

Prediabetes (impaired glucose tolerance)

≥ 6.5%

Diabetes

What do the test results indicate?

HbA1c levels in cases of normal, prediabetes, and diabetes are:

The target HbA1c level for people with diabetes is usually less than 7%. The higher the HbA1c level, the higher the risk of having complications related to diabetes.

A diabetic patient should have an HbA1c test every 3 months to make sure that his/her blood sugar is in the target range.

What are the limitations of the HbA1c test?

HbA1c is not influenced by daily fluctuations in blood glucose level, so

it cannot be used to monitor day-to-day blood glucose concentrations

and is inappropriate to be used for adjusting insulin doses.

Medical conditions that may falsely decrease HbA1c include:

• Anemia
• acute or chronic blood loss
• Thalassemia

HbA1c may be increased falsely in certain medical conditions include:

• kidney failure
• chronic excessive alcohol intake,
• hypertriglyceridemia.