Haemoglobin A1c test, better known as HbA1c blood test, checks the amount of glucose bound to the haemoglobin. Haemoglobin is a substance found in our RBC(Red Blood Cells) that carries oxygen throughout our body. When blood sugar increases in your blood, it binds to haemoglobin, and this process is called Glycation.
The HbA1c blood test is often used to identify both diabetes and prediabetes- a condition characterised by excessive glucose levels, not high enough to be diagnosed as the most common type of diabetes- called Type-2 diabetes. The test is routinely administered in those who have type 1 and type 2 diabetes.
If you are already diagnosed with diabetes, the test is used to monitor your present condition, whether the levels of glucose are within the range and how well the treatment plan is working. The test can also tell you whether you need to adjust your medications for diabetes.
The test checks the average amount of glucose or blood sugar bound to haemoglobin, known as HbA1c, for the past three months. This span is considered since that’s the average lifespan of RBC. Even though the level of HbA1c reflects the blood sugar level for the past three months, it won’t reflect the daily blood sugar swings, i.e., the ups and downs.
If the level of HbA1c in your blood is high, then it may indicate diabetes, a chronic metabolic disease that may lead to health problems such as kidney disease, heart disease and also nerve damage. If your results indicate a high A1c level, then you may have a high risk of diabetic complications and poor blood sugar control.
If you are experiencing any of the below-mentioned symptoms of diabetes, then your doctor may order an HbA1c blood test:
Your doctor may also order an HbA1c test if you have any of the risk factors for developing diabetes, such as:
The HbA1c levels often fluctuate due to various factors such as:
There are no special preparations required prior to this test. The test is performed on a blood sample because HbA1c is unsusceptible to the short-term blood glucose fluctuations, for instance, after taking meals. Blood can be collected for the test without regard to when you had food. There is no need for fasting for the blood test. But you should inform your doctor regarding any medications that you are taking, since medications may affect the results.
Using a small needle, a healthcare professional will draw blood from a vein in your arm. The blood will be collected on a vial or test tube. When the needle goes in and out, you may feel a slight sting. The HbA1c blood test typically lasts for no more than five minutes.
There is minimal risk of having an HbA1c blood test. But you may experience a bruising or slight pain at the puncture site, and these symptoms won’t last long.
Test results are expressed in percentage (%). High HbA1c percentage means higher average glucose levels. The range of HbA1c has different implications:
When you have high HbA1c levels, then you have more risk of developing complications related to diabetes. If you’re diabetic, then it is recommended to keep the level of HbA1c below 7%. A lot of studies have confirmed that diabetes complications can be prevented if the level of HbA1c is kept below 7%. Your doctor may have other recommendations for you, based on your overall health, weight, age and other factors. A combination of a healthy diet, proper medication and regular exercise can certainly bring HbA1c levels down.
If you have diabetes, then you need to take the test every three months to ensure that the levels are within the target range. You may be able to wait for a long time in between the HbA1c blood tests in case if your diabetes is under good control. But it is recommended to take this test at least two times a year.
The test is not administered in children, to identify diabetes, and also not used for gestational diabetes. It is a diabetes that only affects pregnant women who didn’t have diabetes in the past. The same condition is applicable if you have another type of blood disorder or have anaemia, since the test may become inaccurate. Your doctor may recommend other diagnostic tests if you have any of these conditions or are at risk for developing diabetes.
Other factors that may affect your test results are supplements like Vitamin C and Vitamin E, as well as conditions such as Liver disease, kidney disease, and high cholesterol levels.
Maintaining a well-balanced and healthy diet is the key. Besides taking medications, lifestyle changes are effective too. It is important to stay hydrated throughout, exercise regularly, maintain healthy body weight, reduce stress, and also to eat small portions very often.
You have prediabetes when your blood glucose level is between 100 and 125 mg/dL and your HbA1c is between 5.7% and 6.4%.
If you have diabetes, then you need to take the test every 3 to 6 months. If the blood sugar levels are well managed, then HbA1c is measured every six months. But if your diabetes medication treatment changes or if you have a high blood sugar level, then your doctor may order for the test every three months, until the glucose level comes within the acceptable range.
Yes. Doctors also use blood glucose tests that require fasting such as Oral glucose tolerance test and Fasting plasma glucose test to diagnose prediabetes and diabetes. If you have experienced diabetes symptoms, then your doctor may order another blood glucose test which doesn’t require fasting called a Random plasma glucose test.
Laboratory test results may differ from test to test and from day to day. Medical conditions that affect the lifespan of RBC, such as hemodialysis, recent blood loss, erythropoietin treatment, or sickle cell disease can change the HbA1c levels. Another factor is small changes in temperature, sample handling or equipment, even if the same sample is measured repeatedly in the same laboratory.
When the HbA1c test is repeatedly done, then the test results can be somewhat lower or higher than the first result. For instance, an HbA1c reported as 5.8% on one test can be reported as 6.2% when the test is repeated on the same blood sample. This range was larger in the past, but with the recent, stricter quality control standards, it is expected that the results will be more accurate.