What is A1C?
Plus, what it tells you about diabetes risk.
You’re likely to come across the term “A1C” often when learning about diabetes, and for good reason: A1C tests play an important role in helping people with diabetes — as well as those with pre-diabetes — manage their blood sugar levels and potentially avoid certain health conditions. Yet, despite being such an important tool, few people know what A1C is and why it’s worth measuring.
What is A1C?
A1C refers to a measurable signal that’s produced when blood cells become coated in sugar. A1C tests work by examining the blood cells found in a sample of blood — collected via a finger prick or blood draw — and determining the percentage of sugar-coated (pun intended) blood cells. This is why A1C test results are reported as a percentage: A 5% A1C result indicates that roughly 5% of the blood cells in your sample have sugar attached to them.
Why measure A1C?
A1C is an important tool used by physicians to gauge whether a person is at risk of developing diabetes-related health conditions. People who do not have diabetes or pre-diabetes typically have A1C results that fall below 5.7%; while pre-diabetics fall within the range of 5.7%-6.4%. Results above this point indicate that a person may have diabetes.
Unlike other tests which measure the amount of sugar in your blood at one moment in time, such as a blood glucose test, the A1C test gives you an idea of what your average blood sugar has been over the past 2-3 months (that’s why physicians usually advise testing your A1C every few months as a part of routine blood work). Such a measurement can be helpful because it is less variable than the blood glucose test, which can give you different readings depending on the time of day the test is performed.
The A1C test can give you an average over several months because blood cells typically live for 120 days. If over that time a blood cell is exposed to higher levels of sugar, it will have a higher likelihood of becoming coated in it. Diabetics and pre-diabetics will have elevated A1C results because their bodies are having a harder time clearing sugar from the blood. As a result, blood cells are exposed to more sugar over their lifespan and are more likely to develop an A1C signal.
It is possible, with the right guidance, to manage your A1C levels. One size doesn’t fit all, so you should talk to your physician about what a healthy A1C result looks like for you, and how to get there. Often, A1C levels are controlled through a combination of diet, exercise, and various therapeutics. New developments also suggest that altering a person’s gut microbiome may also be helpful.
Sugar coated blood cells?
What do we mean by sugar coated blood cells? A1C tests are measuring the percentage of cells in your blood that are coated in a type of sugar known as glucose. Glucose is arguably one of the most important sugars on the planet because it’s loaded with energy, energy that our cells can use to fuel the basic processes that keep us alive (such as breathing, metabolizing food, and thinking).
Every cell in your body needs glucose to survive, which means that glucose has to somehow be transported from your digestive tract to the rest of your body. To do this, glucose is dumped into the bloodstream which acts as a highway of sorts, helping to rush molecules all around the body. Along with glucose, blood cells carrying oxygen are also using the bloodstream as a highway. It’s here in the bloodstream where glucose becomes irreversibly attached to a protein in blood cells, known as hemoglobin, and the A1C signals originate.
- Eyth, Emily. “Hemoglobin A1C.” StatPearls [Internet]., U.S. National Library of Medicine, 30 Oct. 2019, www.ncbi.nlm.nih.gov/books/NBK549816/.
- Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd Edition. LexisNexis UK, 1990. https://www.ncbi.nlm.nih.gov/books/NBK248/.
- “A1C And EAG.” A1C And EAG | ADA, www.diabetes.org/diabetes/a1c-test-meaning/a1c-and-eag.