Proper diet, exercise, and medications are all essential for managing diabetes. Aside from feeling healthier when managed correctly, there are concrete ways to track your progress. Currently the HbA1c test is one of the best ways to check how well controlled your diabetes is.
How the HbA1c Test Works
Your red blood cells contain small protein molecules called hemoglobin that are responsible for carrying oxygen within your body. When glucose (sugar) in your blood attaches to these protein molecules, it forms glycosylated hemoglobin. This is also known as glycated hemoglobin or HbA1c.
The HbA1c test measures the percentage of HbA1c (red blood cells coated with glucose) from a sample of your blood. Since red blood cells have a life cycle of two or three months, and because HbA1c levels change slowly with time, this test is an excellent indicator of how high your blood glucose levels have been on average over a long period of time.
The more glucose there is in the blood, the higher percentage level of HbA1c will be detected. People with normal blood sugar have HbA1c levels of less or equal to 5.6%. If your
HbA1c is more or equal to 6.5%, you meet the criteria for diagnosis of diabetes. If your HbA1c is between 5.7-6.4%, you meet the criteria for diagnosis of prediabetes. However, this needs to be confirmed with other tests such as the fasting blood sugar test or the oral glucose tolerance test.
The Purpose of HbA1c Testing
The HbA1c test allows doctors to get an overall sense of how well you are managing your diabetes – whether type 1 or type 2 – over 3 months period. If you are diagnosed with pre-diabetes, this test is used to establish your baseline HbA1c levels.
Doctors also use this information to make adjustments to your diet, exercise, and medication regimen. The frequency with which this test is done depends on your individual treatment plan and goal, as well as how well you’ve been managing your diabetes in the past, but it is usually done every 3 months.
Test results can be obtained very quickly and can be conducted as an individual test at Bumrungrad or as part of a health check-up package. Since you can eat and drink as normal, little preparation is required before the test.
Additional Diabetes Tests
Doctors will often recommend the HbA1c test along with other glucose tests. Since glucose levels depend on time, meal schedule, diet, and exercise – and therefore can fluctuate hour to hour and day to day – the HbA1c test best reflects your overall blood sugar level management and not just the management for one day.
However, if your HbA1c test results aren’t consistent, or if you are pregnant or have an abnormal form of hemoglobin, other blood tests can be used to test blood glucose levels, including:
Fasting Plasma Glucose: Tests blood glucose levels after fasting a minimum of eight hours or overnight. A fasting glucose level of less or equal to 100mg/dL is normal, whereas 126 mg/dL or more in two separate tests indicate diabetes.
Random Blood Sugar Test: Regardless of when you have last eaten, a sample of blood will be taken. A blood glucose level of 200mg/dL with symptoms of diabetes mellitusindicate the possibility of type 2 diabetes mellitus (T2DM).
Oral Glucose Tolerance Test: First, your fasting blood sugar level is measured, and then you are given a sugary drink. Your blood glucose levels are then tested over the course of two hours. If after two hours you have a reading of 200mg/dL or higher, this indicates diabetes.
Speak more with your doctor about which test is right for you in helping you diagnosis or manage your diabetes.
By Dr. Nalurporn Chokrungvaranon, Endocrinologist, Diabetes Program, Bumrungrad Hospital
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