Know Your Numbers: HbA1C Test For Diabetes

Know Your Numbers: HbA1C Test For Diabetes

If you are suffering from diabetes or anyone in your family has diabetes, then you might be used to seeing a test report for glycosylated haemoglobin, commonly known as HbA1C. It is one of the key tests for diabetes that not only helps in the diagnosis but also helps you to know how well the blood glucose is managed over time.

Whether you are prediabetic, a diabetic with insulin dependency or a diabetic with your blood glucose levels under control through medication, periodic HbA1c testing is a must. The HbA1c levels for prediabetes and diabetes are different. Here’s what you need to know about the test results.

What is HbA1C?

It is a blood test that measures a person’s average blood glucose level over the past 2 to 3 months. It is ideally used to check how well your diabetes is managed with medication.

Is HbA1c the only test for diabetes?

The diagnosis of diabetes is based on three key parameters — fasting blood glucose level, postprandial (2 hours after a meal) glucose level and HbA1c level. If your fasting and postprandial levels are high, then HbA1c is advised to confirm the diagnosis. All three test results are evaluated by the doctor to diagnose diabetes and not just one.

What is normal HbA1c?

According to the American Diabetes Association guidelines for Diabetes testing, the values for HbA1c are as follows:

Normal: less than 5.7%

Prediabetes: 5.7% to 6.4%

Diabetes: 6.5% or higher

The A1C target in pregnancy is 6–6.5%.

Preprandial or fasting: Less than 100 mg/dl

Postprandial (1-2 hours after meals): Less than 140 mg/dl

What should be HbA1c targets to manage diabetics?

The American Diabetes Association suggests the following targets for most non-pregnant adults  with diabetes:

HbA1c: The ideal range of HbA1c for people with diabetes under control and no known health complications is less than 7%. However, a more stringent target of 6.5% can be recommended if you have diabetes for a short period and no significant cardiovascular complications. But if you have a history of severe hypoglycemia, other co-morbid conditions and diabetes related complications or long-standing diabetes, then it is advised that you aim for less than 8%.

Preprandial or fasting: 80–130 mg/dl

Postprandial (1-2 hours after meals): Less than 180 mg/dl

How often should HbA1c levels be tested?

If you are diabetic, most Indian endocrinologists recommend that you get your HbA1c level tested every three months. But the frequency is usually decided by your doctor according to your reports and other health issues. If you are prediabetic, then it is advised to check the level once a year.

HbA1c for diabetes: What you need to know

-HbA1c testing should always be done by High Performance Liquid Chromatography (HPLC) method as it is the most accurate method. So check with the lab whether they use this method.

-It is not recommended as a screening test for cystic fibrosis–related diabetes and or Type-1 diabetes.

-If you are around 40 – 70 years and suffer from high blood pressure, high cholesterol level or have a body mass index greater than 25 kg/m2, it is advised to undergo a screening test for diabetes.

-Glucose and HbA1C levels rise well before the clinical onset of diabetes, thus helping in the diagnosis of diabetes as well as diabetic ketoacidosis well before the onset of the condition.

-If the results of HbA1c indicate diabetes, it is recommended that the same test be repeated or a different test for checking blood glucose level (usually fasting blood glucose level) be performed without delay using a new blood sample for confirmation.

-You do not have to fast for HbA1c testing.

-You don’t have to skip your medicines the day you are getting the test.

(With inputs from Dr. Pradeep Gadge)

References:

American Diabetes Association. 6. Glycemic Targets. Diabetes Care 2017; 40(Suppl 1): S48-s56

~by-1mg