Understanding Hemoglobin A1C and How to Keep it Low

Hemoglobin A1C is a blood test used to diagnose and monitor prediabetes and diabetes type 2.

Understanding the results of routine blood tests can be daunting. Most patients want to avoid taking medications, and hope that everything turns out normal. If you’re at risk for diabetes, your healthcare provider will routinely check your Hemoglobin A1C (Hb1Ac). From a patient’s perspective, a normal result means no new prescriptions to pay for, no new potential side effects, and, especially if you’re needle-phobic, no daily finger sticks. 

Unlike the common glucose test, which is also routinely checked as part of a metabolic panel, HbA1c is a measure of your blood glucose level over several months. Cutting sugar out the day before your test won’t save you. 

The HbA1c Test: What is it exactly?

If your body can’t process the amount of sugar you eat, your blood glucose levels increase. The glucose sticks to hemoglobin, a protein in red blood cells that transports oxygen throughout your body. The more glucose in your blood, the more hemoglobin will be coated. The reason HbA1c reflects blood sugar levels for a few months is because that’s about how long a red blood cell lives. Once glucose binds to hemoglobin, it’s there until the cell dies. (1)

So what’s normal?

Generally speaking, non-diabetics will have an A1C less than 5.7%. A person is considered prediabetic if their A1C is between 5.7 and 6.4%. An A1C above 6.5% is indicative of diabetes. (2)

Who needs to get tested?

The frequency of testing will vary based on a person’s risk factors. Reasons to get tested include: positive family history of type 2 diabetes, being overweight, not getting enough exercise, high blood pressure, high cholesterol, heart disease, history of gestational diabetes, polycystic ovaries, being over 45, and having symptoms associated with diabetes. (1)

But why me, why now?

The body may become resistant to insulin over time. While the biggest risk factors are obesity and living a sedentary lifestyle, these aren’t the only ones. Some people are genetically predisposed. Hormonal changes due to medication or menopause can also play a role. Chronic inflammation, as in the case of autoimmune disease, can also interfere with insulin signaling. Insulin resistance can develop gradually over time and is often not associated with any symptoms. It’s best to get checked. Making simple lifestyle changes can prevent serious complications down the road. (1)

How can I keep my HbA1c low?

You can start by making simple changes, one at a time. For example, if you drink sugary drinks, including fruit juices, try switching to sugar-free alternatives. While drinking water is best, artificial sweeteners have made it so we can enjoy our favorite flavors without raising our blood glucose levels.

Higher consumption of whole grains is associated with a lower risk of type 2 diabetes. (3)

Switch to whole grains. (3) Swap your white bread and white rice for brown. When buying bread, be sure to check the ingredient list for the word “whole.” Sometimes bread is made from a combination of flours. It may also contain coloring agents that make it appear brown.

Increased muscle mass is associated with reductions in HbA1c. (5)

If you aren’t exercising, start walking. You can walk on a treadmill while watching your favorite TV show. Consistent, routine physical activity can be as effective as diabetes medication. (4) Researchers also strongly advocate resistance training. People with higher muscle mass have a lower risk of developing type 2 diabetes. Muscle cells are highly sensitive to insulin and absorb glucose after meals. (5) The benefits of increased muscle mass also include: increased bone density, protection from injury, increased energy levels and improved cognition. (6)

Studies show that poor sleep promotes glucose intolerance and worsens prediabetes and diabetes. (7)

Get enough quality sleep. Sleep deprivation can cause reduced insulin sensitivity. Researchers have linked type 2 diabetes to both short sleep periods (less than 6 hours) and, to a lesser extent, excessive sleep periods (more than 9 hours). It may be necessary to treat an underlying condition, such as sleep apnea or depression, in order to get a good night’s sleep. Since the body regulates numerous vital functions during sleep, the benefits are worth it. (8)

References

1. "Hemoglobin A1C (HbA1c) Test." MedlinePlus. Updated September 6, 2022. Accessed April 6, 2025. https://medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/

2. "Understanding A1C." American Diabetes Association. Accessed April 6, 2025. https://diabetes.org/about-diabetes/a1c

3. Hu Y, Ding M, Sampson L, Willett WC, Manson JE, Wang M, Rosner B, Hu FB, Sun Q. Intake of whole grain foods and risk of type 2 diabetes: results from three prospective cohort studies. BMJ. 2020 Jul 8;370:m2206. doi: 10.1136/bmj.m2206. PMID: 32641435; PMCID: PMC7341349

4. "Why Exercise Matters for Those with Diabetes." Yale Medicine. Updated October 30, 2023. Accessed April 6, 2025. https://www.yalemedicine.org/news/exercise-for-diabetes

5. Kirwan JP, Sacks J, Nieuwoudt S. The essential role of exercise in the management of type 2 diabetes. Cleve Clin J Med. 2017 Jul;84(7 Suppl 1):S15-S21. doi: 10.3949/ccjm.84.s1.03. PMID: 28708479; PMCID: PMC5846677.

6. "Strength training: Get stronger, leaner, healthier." Mayo Clinic. Accessed April 6, 2025. https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/strength-training/art-20046670

7. "The Impact of Poor Sleep on Type 2 Diabetes." National Institute of Diabetes and Digestive and Kidney Diseases. Accessed April 6, 2025. https://www.niddk.nih.gov/health-information/professionals/diabetes-discoveries-practice/the-impact-of-poor-sleep-on-type-2-diabetes#:~:text=A:%20Yes.,for%20developing%20type%202%20diabetes.

8. Darraj A. The Link Between Sleeping and Type 2 Diabetes: A Systematic Review. Cureus. 2023 Nov 3;15(11):e48228. doi: 10.7759/cureus.48228. PMID: 38050514; PMCID: PMC10693913.

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