A1C: What Is It and What Does It Mean?


You might have heard of a test called hemoglobin A1C. Maybe your doctor recommended that you get this test, or maybe you saw the results of an A1C test among your other most recent tests. It is related to your blood sugar levels, and is often used to test for or monitor prediabetes and diabetes.

 

What Is A1C?


Hemoglobin A1C is also known as glycated hemoglobin or simply as A1C. It is a measure of your blood sugar (blood glucose) levels over the past 3 months. Here is how it works.

Hemoglobin is a protein in your blood that carries oxygen to the cells in your body, and hemoglobin A1C is the most common type of hemoglobin. As sugar, or glucose, circulates in the bloodstream, some of it naturally attaches to the cells or cell components it passes, including to hemoglobin A1C. The result is glycated hemoglobin.

The A1C test measures the percent of your hemoglobin A1C that is attached, or bound, to glucose. The percent of hemoglobin A1C that is bound to sugar is higher when your average blood sugar levels have been higher. The percent is lower if your average blood sugar levels have been lower.

 

A1C Level in Diabetes


Your doctor can use the results of an A1C test to diagnose prediabetes. A “normal” A1C level is under 5.7%. You can be diagnosed with diabetes if your A1C is higher than than 6.5%. In prediabetes, A1C is higher than normal but lower than in diabetes. An A1C level for prediabetes is 5.7 to 6.4%.

Your A1C results can also be used to monitor prediabetes or diabetes if you have already been diagnosed. If you have prediabetes, your goal might be to reverse prediabetes and lower your A1C to under 5.7%. For otherwise healthy individuals with diabetes, a common goal to lower the risk for complications is to keep A1C under 7%. For some people with diabetes, such as older adults or people with complications, reducing or maintaining A1C under 8% may be safer. In general, your risk for diabetes complications rises when A1C is higher.

 

Purpose of the A1C Test


Your doctor may order an A1C test if she suspects that you have prediabetes or diabetes. This can happen if you have risk factors, such as being overweight or obese, being an older adult, being physically inactive, or having a family history of diabetes. You should get your A1C tested every 3 years if you had gestational diabetes during pregnancy.

Another reason why your doctor might want an A1C test to diagnose prediabetes or diabetes is to confirm the results of a previous A1C test that came back high. The American Diabetes Association (ADA) suggests getting a second test on a different day before diagnosing prediabetes or diabetes.[1]

You can also use the A1C test to add to your home blood sugar testing routine as you monitor diabetes. While the blood glucose test only shows what your glucose is at that moment, the A1C test give an average over the past three months. An A1C test could confirm the high or low blood sugar values that you have measured at home, or it could show that those values have not been showing the full picture. You should be tested yearly if you have prediabetes.

 

A1C and Average Blood Glucose Levels


The A1C indicates your blood glucose control over the past three months. You can get an idea of what your A1C means by converting it to “estimated average glucose,” or eAG. The ADA provides a calculator and chart to help you.

Some common values are:

Hemoglobin A1C, % Estimated Average Glucose (eAG), mg/dl
5.7 (first prediabetic value)
117
6.4 (highest value for prediabetes)
137
6.5 (lowest value for diabetes)
140
7 (goal for low-risk diabetes patients)
154
8 (goal for high-risk diabetes patients)
183
 

How to Take an A1C Test


The A1C test is easy to take. You can take it at the laboratory where you get your regular blood tests, such as cholesterol and blood sugar. Just ask your doctor to put in the order, just like she does for your other blood tests.

You can take the A1C test at any time of the day. While it is always better to be well-hydrated when you get your blood drawn, you do not need to make special preparations for the A1C test. You do not need to fast, skip the caffeine, or refrain from exercising. The results should come the way you always get your test results, such as directly to you or from your doctor.

The ADA offers a quick translation of your A1C results, although you should always get the definitive interpretation from your doctor. The ADA provides the following table.[2]

 

Signs of High A1C


The signs of high A1C are the same as those of high blood glucose. You are unlikely to notice any signs or symptoms if you have prediabetes, or A1C between 5.7 and 6.4%, although a few patients develop a condition called acanthosis nigricans. This includes velvety, darkened patches of skin on your neck or underarms.

You are more likely to have symptoms if your A1C is over 6.5% and puts you in the diabetic range. You could have excessive thirst combined with increased need to urinate. You might have unusually high levels of hunger along with unexpected weight loss. Some patients experience blurred vision and pain or tingling in the hands and feet from diabetic neuropathy. Contact your doctor if you have any of these signs because they could show that your blood sugar is uncontrolled and that you are at risk for diabetes complications.

 

How to Lower A1C


In many cases, you can lower A1C without medications. Lifestyle changes are often enough to reverse or slow insulin resistance and the progression of prediabetes. If your doctor does prescribe medications to manage blood sugar, your healthy lifestyle can make the medications more effective or allow you to take smaller doses to get the results you need.

Lifestyle changes that help lower A1C include:

  • Losing weight if you are carrying extra pounds.

  • Eating a healthy diet with foods that help lower blood sugar.

  • Increasing physical activity.

  • Sleeping enough.

  • Reducing or managing stress.

 

Weight Loss and Diet to Lower A1C


Losing extra weight is a top priority for reducing A1C. Extra body weight is a risk factor for diabetes, and those extra pounds may be a cause of insulin resistance and high A1C. Losing extra pounds can be as beneficial as gaining them is harmful. In fact, one study found that each kilogram (2.2-lb.) reduction of body weight was linked to a decrease in A1C of 0.1%.[3] That is heartening news if you are far from a so-called “ideal” body weight, but losing a few pounds seems within reach.

You can aim for modest, sustained weight loss with small changes to your regular routine.

  • Use a smaller plate or bowl to make portion sizes smaller, naturally.

  • Eat another helping of vegetables before serving yourself seconds of anything else.

  • Drink water instead of beverages with calories.

  • Eat more filling foods, such as vegetables, fish, and beans.

  • Reduce portion sizes of sugary, starchy, and fatty foods.

  • Use a health coach to log your food and track your weight.


Along with losing weight, choosing healthier foods can lower A1C and prevent or delay type 2 diabetes or lower the risk for complications. The best diet for prediabetes and diabetes is full of foods that may increase insulin sensitivity, lower blood sugar or A1C levels, or reduce the risk for diabetes comorbidities, such as high blood pressure. These foods include the following.

  • Fresh or frozen vegetables without added salt.

  • Fresh or frozen fruit without added sugar.

  • Small portions of foods rich in monounsaturated fats, such as avocados, olive oil, nuts, and peanuts.

  • Omega-3 fats, which are in fatty fish and flaxseed.

  • Legumes, such as beans, lentils, and split peas.

  • Tofu, eggs, fish, and other lean proteins.

  • Whole grains, such as whole-grain bread and pasta, brown rice, oatmeal, whole-grain breakfast cereal, and quinoa.


The worst foods for diabetes can drive up blood sugar and A1C levels. Some of the unhealthy foods to avoid can increase insulin resistance or raise your risk for related health problems. When you can, avoid or limit portions of foods such as the following.

  • Sugar-sweetened beverages, such as soft drinks, energy drinks, sports drinks, coffee with sugar or syrup, and sweet tea.

  • Desserts and breakfast pastries, such as candy, ice cream, cake, pies, cookies, cinnamon rolls, muffins, danish, and custard.

  • Butter, shortening, and lard.

  • Processed meat, such as bologna, salami, hot dogs, sausages, ham, and pepperoni.

  • Fatty red meat, such as fatty steaks, regular ground beef, and ribs.

  • Sugar-sweetened processed foods, such as flavored oatmeal and yogurt, jam, and tomato sauce.

  • Refined grains, such as white bread, pasta, and rice, pretzels, crackers, and refined breakfast cereals.

  • Pizza, burgers, tacos, burritos, fried rice, macaroni and cheese, and other low-nutrient fast foods or prepared foods with refined grains and excess fat.

  • Dried fruit, fruit juice, and fruit canned in syrup or frozen with sugar.


The list may be long, but you can get help by using a digital smartphone app such as Lark DPP or Lark Diabetes. Your personal health coach guides you in making smarter choices, one step at a time, without making you overwhelmed.

 

Activity, Sleep, and Stress Reduction to Lower A1C Naturally


Diet and exercise are powerful for lowering A1C, and there are additional healthy changes you can make throughout the day and even all night.

Aerobic Exercise: Physical activity increases insulin sensitivity for about 24 hours after you work out, so that daily workout is a great idea. Hit the gym, walk, swim, garden, play tennis, or do whatever you love as long as you are moving. Aim for 150 minutes or more per week.

Pumping Iron: Strength exercises also raise insulin sensitivity. Do body weight exercises, such as squats, lunges, and push-ups, or use equipment such as weighted balls, dumbbells, resistance bands, and weight machines.

Sleep: Sleep deprivation lowers insulin sensitivity and raises blood glucose, not to mention increases carb cravings, reduces your ability to resist cravings, and makes you hungrier. No, thanks! Avoid being short on sleep by setting aside enough time for sleep each night, turning off your smartphone and other screens before bedtime, and improving sleep quality by sleeping in a quiet, dark room. You may be short on sleep if you have a morning headache, feel moody or unfocused, or need caffeine.

Stress Reduction: Stress comes from work, relationships, finances, health concerns, and life events. Stress is everywhere, and it can raise A1C if you let it be negative. You can reduce stress by letting go of what you cannot control and by not setting unrealistic expectations for yourself. You can better manage the rest of your stress by embracing it and focusing on what you can control.

 

Help with Controlling A1C


These healthy lifestyle changes can be a lot to think about, but there is no need to get overwhelmed. First, you can get results with small changes, so you can pick and choose which healthy changes to make as you are ready.

Second, help is available. Besides contacting your doctor and healthcare team for information and support, you can depend on Lark 24/7 to guide healthy choices, monitor your sleep, activity, and diet, and support you in your quest to lower A1C.


Reference

1.  Diabetes Care. 2018 Jan;41(Suppl 1):S1-S2. doi: 10.2337/dc18-Sint01. Introduction: Standards of Medical Care in Diabetes-2018.

2.  Your A1C Results: What Do They Mean? Clinical Diabetes 2006 Jan; 24(1): 9-9. https://doi.org/10.2337/diaclin.24.1.9. http://clinical.diabetesjournals.org/content/24/1/9#T1

3.  Gummesson A, Nyman E, Knutsson M, Karpefors M. Effect of weight reduction on glycated haemoglobin in weight loss trials in patients with type 2 diabetes. Diabetes Obes Metab. 2017 Sep;19(9):1295-1305. doi: 10.1111/dom.12971. Epub 2017 May 22. https://www.ncbi.nlm.nih.gov/pubmed/28417575

Natalie Stein

Exercise, Fitness & Nutrition Expert | Assistant Professor of Public Health