“A1C is a marker of the average blood sugar in the previous three months,” explains Samar Hafida, MD, an endocrinologist at Joslin Diabetes Center in Boston. “It measures the big picture of what’s going on,” she says. It’s also often used to estimate whether you’re meeting your blood glucose goals with lifestyle changes or medication, she says. And it can be used to diagnose type 2 diabetes, along with other blood tests or symptoms of high blood glucose, according to the American Diabetes Association (ADA), with a level between 5.7 and 6.4 indicating prediabetes and 6.5 percent or above indicating diabetes.
How Does the A1C Test Work?
It works by measuring how much glucose (sugar) is clinging to the hemoglobin in your blood cells. Hemoglobin is the part of red blood cells that carries oxygen to other cells. The higher your blood glucose level, the more glucose will be attached to the hemoglobin, according to the National Institute of Diabetes and Digestive and Kidney Diseases. The result is your A1C, which is reported as a percentage. A normal A1C level is below 5.7 percent. Even though the usefulness of A1C is up for debate, the general consensus in the medical community, and the recommendation of the American Diabetes Association 2019 Standards of Medical Care in Diabetes, is that your healthcare provider should measure your A1C two to three times a year.
How Accurate Is the A1C Test?
Some blood disorders can make the A1C test less accurate. For example, African Americans with sickle-cell trait, an inherited red blood disorder, can have lower A1C readings compared with those without sickle-cell trait, according to a study published in February 2017 in the Journal of the American Medical Association. In other words, the A1C test may underestimate the actual number, say the authors. Other conditions can affect A1C, such as undergoing dialysis, which is a treatment to filter your blood when your kidneys fail. Pregnancy, recent blood loss or transfusion, certain medicines, and anemia, a condition in which you don’t have enough healthy red blood cells, can also affect A1C, according to the Centers for Disease Control and Prevention (CDC). In those cases, your provider may use a different test to measure your blood glucose, says Veronica Brady, PhD, a nurse practitioner and certified diabetes educator at the University of Nevada School of Medicine in Reno. “I think it’s important for people to know that A1C is a good test for most people, but there are rare or unusual cases where it’s not reflective of average blood sugar,” says Dr. Hafida. Your ethnicity might also affect your A1C. “We know AfricanAmericans generally have a higher A1C than other ethnicities, so their [A1C] targets might be slightly different,” says Hafida. A study published in Diabetes Care found that Hispanics, American Indians, and Asians also tend to have higher A1Cs than whites. “The overall recommendation is that you try to get the A1C as low as you can without causing adverse side effects,” says Brady. Such side effects could include episodes of severe low blood sugar, she notes, which multiple studies have linked to health problems like dementia, poor quality of life, and early death. “People certainly need to work with their healthcare provider to determine what the goal should be for them,” says Brady.
4 Lifestyle Changes That Can Help Lower Your A1C
If your A1C indicates that you have prediabetes or diabetes, there are many different medicines that work in different ways to lower blood glucose levels. But lifestyle changes can also, over time, deliver benefits, according to a study published in August 2017 in the Journal of the American Medical Association. Relatively simple steps that can help prevent or delay complications, according to an article published in January 2017 in the journal Diabetes Care, include: Keep in mind that it can take time for positive changes to reflect in your A1C numbers, says Brady. She adds that people are sometimes surprised to see that their A1C hasn’t changed from one visit to the next. Hafida hears the same frustrations. Don’t get discouraged if your recent efforts haven’t yet lowered your A1C, she says. Bring up any concerns with your healthcare provider.
