Person preparing to collect finger prick blood sample while wondering how high blood sugar affects the heart

How Blood Sugar Levels Affect Your Risk of Heart Disease

Updated December 12, 2023.

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Too much blood sugar can contribute to a buildup of plaque in your arteries, which can eventually restrict the flow of blood to your body’s vital organs (like the brain). Heart disease can occur as a result – as well as heart attack or stroke. As such, high blood sugar is a major risk factor for heart disease.

So is your blood sugar climbing to heart-harming levels? You can find out with the Everlywell at-home HbA1c test kit. By taking this test, you can easily check your average blood sugar levels from the past 90-120 days.

Read on to discover more about HbA1c – and how blood sugar levels affect your risk of heart disease.

What Is HbA1c?

Your HbA1c (or just A1c) level shows your average blood sugar level from the previous 3 months or so.

An HbA1c test measures the percentage of the hemoglobin in your red blood cells that are covered in sugar from your bloodstream – giving you a good idea of your average blood sugar level. (Hemoglobin is a type of protein in your red blood cells.)

This way of measuring blood sugar is the key difference between an HbA1c test and a blood glucose meter (commonly called a glucometer). A blood glucose meter tells you what your blood sugar levels are like at the specific moment you take the measurement – in milligrams per deciliter, or mg/dL.

However, blood sugar levels can change quite a lot throughout the day in response to meals you eat and your physical activity. Since an HbA1c test gives you a 90-day average of your blood sugar, it’s often much more useful for tracking long-term changes and trends in your blood sugar levels.

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Family History and Blood Sugar

If one of your first-degree relatives – such as a parent or sibling – has a history of diabetes, you’re more likely to have high HbA1c levels (even if you yourself do not have diabetes) [1].

So if diabetes runs in the family, consider monitoring your HbA1c levels on a regular basis – before high blood sugar has a chance to sneak up on you and potentially harm your heart health.

How Blood Sugar Levels Affect Heart Disease Risk

Research shows that higher HbA1c levels are generally linked with a higher risk of heart disease. A study published in 2017 found that the most ideal HbA1c level for people without diabetes is in the 5.0% to 6.0% range [2]. Beyond 6.0%, the risk of death from heart disease rises significantly. That same study discovered that individuals with diabetes face a much greater risk of death from heart disease if their HbA1c levels reach past 8.0%.

(Note that these numbers don’t apply to everyone, so discuss your HbA1c level with your healthcare provider before choosing an HbA1c target that’s right for you.)

How Often Should You Check HbA1c Levels?

You should check your HbA1c levels more frequently if you have diabetes or prediabetes (a blood sugar level that is almost – but not quite – in the diabetic range).

The exact guidelines depend on how well-controlled your blood sugar level is, as well as other factors like pregnancy.

Learn more here: High Blood Sugar? Here’s How Often You Should Check Your HbA1c Levels.

It’s important to remember that it will take at least 90 days for your red blood cells to turn over and for you to see any positive changes in your HbA1c from diet or lifestyle changes (or medication changes that your doctor may make).

How Can You Maintain a Healthy Blood Sugar Level?

Keep these points in mind if you’d like to maintain a healthy blood sugar level:

  • Quit smoking if you currently smoke - Nicotine can increase your blood sugar levels by changing how your cells respond to insulin (the hormone that tells your cells to take sugar out of your bloodstream) [3]. So if you currently smoke, ask your doctor about ways to quit smoking.
  • Include more fiber in your diet - Fiber-filled foods – like oats and barley, and vegetables like broccoli, leafy greens, and carrots – can lower blood sugar levels.
  • Make regular exercise a priority - A quick bout of exercise can lower blood sugar levels almost immediately because your muscles burn sugar for energy during physical activity. Regular exercise, though, is what matters most here: over time, consistent exercise can make your cells more responsive to insulin, a hormone which helps your body control blood sugar levels.

Test Your Blood Sugar Levels at Home with an Easy-to-Use HbA1c Kit

It’s easy to stay on top of your blood sugar numbers with the Everlywell at-home HbA1c kit. Everything you need for taking the test is included in the kit, including a prepaid shipping label for mailing your blood sample to the lab. And you can view your results – on a secure online platform – just days after the lab receives your sample.

So if you want to be proactive about your heart health, try the HbA1c kit – a convenient, practical way to test your blood sugar levels.

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Everlywell makes lab testing easy and convenient with at-home collection and digital results in days. Learn More