The A1C blood sugar test, which measures the average amount of glucose in your blood can give false or inaccurate results in some people.
The hemoglobin A1C test is a useful tool to help monitor glucose control or diagnose diabetes, but it is not foolproof. According to experts, the A1C can be falsely elevated due to certain medications or health conditions, which may interfere with the test results, delivering an inaccurate or false result. This can include a false high result. Doctors may suspect an inaccurate result if your A1C test results and your glucose levels do not seem to correlate.
What are the health conditions that may affect A1C results?
A few health conditions can make your A1C test levels falsely high, which include those that affect your red blood cells. A few of these include:
Anemia
Anemia, or deficiency of iron increases A1C levels which causes symptoms like weakness, fatigue, pale skin, and breathlessness, Anemia affects 30 per cent of people across the world. According to doctors, vegans and those who are vegetarians tend to have a higher risk of developing iron deficiency.
Type 1 diabetes
If you get A1C levels high despite proper management, you may not have type 2 diabetes. Studies say at least 12 per cent of those with type 2 diabetes have latent autoimmune diabetes or LADA, which the American Diabetes Association describes as a subtype of type 1 diabetes.
High-stress levels
Those with chronically high-stress levels have raised blood sugar levels and insulin resistance.
Medication and supplements
Doctors say there are many prescription medications that affect A1C testing, which include drugs that affect your hemoglobin and the life span of these red blood cells. A few of these are:
- Steroids
- Cancer medicines
- Treatments for hepatitis or HIV
Doctors say you need to be sure that doctors order your A1C test with an accurate list of your medications and any supplements that you regularly consume. Studies say high levels of vitamin E and vitamin C falsely elevate A1C levels – depending on whether the lab measures your A1C with electrophoresis – which shows a false increase, or chromatography, which can return a false decrease.
How is the A1C test calculated?
A1C testing relies totally on hemoglobin – a part of the red blood cell that carries oxygen throughout your body. When you have glucose in your blood, it sticks to hemoglobin – which stays there for around three months, around the time it takes for an average red blood cell to live. The A1C test measures the average amount of glucose that has been attached to hemoglobin over time. Because the A1C test measures glucose levels over a period of time, it provides more information about blood sugar than a single blood sugar test. Calculated in percentage, the A1C level means:
- Less than 5.7 per cent means you do not have diabetes
- Between 5.7-6.4 per cent signals prediabetes
- More than 6.5 per cent usually indicate Type 2 diabetes (or Type 1 diabetes).