Diabetes is more than a blood sugar disorder. It affects nearly every system in the body, including the cardiovascular system. Early management can help reduce some very unpleasant complications.
Diabetes is so prevalent that most people have a basic understanding of what it is by now. It affects millions – over 40 million people in the United States had diabetes in 2023 and another 115 million had prediabetes.1
While many people think of diabetes primarily as a blood sugar disorder, it actually contributes to a wide range of serious health complications. Persistently elevated blood sugar can damage blood vessels, nerves, and vital organs and increase the risk of kidney disease, vision loss, and cardiovascular disease.
What Diabetes Does to the Body
To understand why diabetes raises heart disease risk, it helps to understand what high blood sugar does throughout the body.
Diabetes is a chronic condition that affects how the body processes glucose (sugar). Under normal circumstances, the pancreas produces insulin, a hormone that helps move glucose from the bloodstream into cells where it can be used for fuel.
The immune system attacks the insulin-producing cells in the pancreas in type 1 diabetes, resulting in the body producing little or no insulin. In type 2 diabetes, the body’s cells become resistant to insulin, making it difficult for them to use glucose. Both type 1 and type 2 diabetes have genetic influences, but type 1 is primarily an autoimmune disease, and type 2 is the result of insulin resistance that develops over time due largely to lifestyle factors. Gestational diabetes can come on during pregnancy and increase the risk of developing type 2 diabetes later in life. In each instance, glucose builds up in the bloodstream, leading to hyperglycemia (high blood sugar).
Chronically high blood sugar wreaks havoc in the body as cells struggle to access the fuel they need to perform basic functions. It leads to fatigue and broader metabolic dysfunction.
Insulin resistance is closely linked to an increase in visceral fat, the type of fat that accumulates deep within the abdomen and surrounds internal organs. Unlike the fat you can pinch under the skin, visceral fat releases inflammatory substances that can worsen insulin resistance, contribute to chronic inflammation, and increase cardiovascular disease risk. In the liver and kidney specifically, it leads to metabolic dysfunction-associated steatotic liver disease (MASLD), also known as nonalcoholic fatty liver disease, and diabetic kidney disease. Both of those conditions have an effect on the cardiovascular system.
That’s not all. Diabetes also affects the nervous system and circulation. Damage to nerves (diabetic neuropathy) causes numbness, tingling, pain, or weakness, particularly in the hands and feet, and impaired circulation makes it more difficult for wounds to heal and increases susceptibility to infections that can become gangrenous.
Diabetes and Cardiovascular Strain
None of what diabetes does to the body is good, and one of the most significant consequences is damage to blood vessels. Elevated glucose levels can damage the lining of blood vessels, making them less flexible and impairing their function. High blood sugar also promotes inflammation and oxidative stress, both of which can accelerate damage to the circulatory system. Poor circulation means tissues aren’t getting the oxygen and nutrients they need.
As blood vessels become impaired, the risk of developing cardiovascular complications increases. Unhealthy cholesterol patterns begin to emerge that end up contributing to atherosclerosis (narrowing and hardening of arteries) and increasing the risk of coronary artery disease, heart attack, stroke, and peripheral artery disease. Many people with diabetes also develop high blood pressure, which places additional strain on the heart.
Diabetes is also a likely contributor to cardiac arrhythmias. Researchers have observed that people with diabetes have a significantly higher likelihood of developing atrial fibrillation than those without diabetes, and some studies suggest that higher blood glucose levels are associated with an even greater risk. Diabetes may also contribute to other rhythm disturbances through changes in the heart’s structure, including fibrosis, fat deposition around the heart, and thickening of the heart muscle. These alterations can interfere with the normal transmission of electrical signals and make abnormal heart rhythms more likely.2
The effects of diabetes are systemic and progressive. But many complications can be prevented or delayed through effective management. Regular physical activity, a heart-healthy diet, weight management, blood pressure control, cholesterol management, smoking cessation, and routine medical care are interventions within an individual’s control. Sometimes medications are necessary and can be cardioprotective while managing other conditions, so regular discussions with a healthcare provider are also an important part of long-term disease management.
Dr. Tordini is a part of Florida Medical Clinic, Orlando Health.
REFERENCES:
- U.S. Centers for Disease Control and Prevention. (2026, January 21). National Diabetes Statistics Report. CDC. https://www.cdc.gov/diabetes/php/data-research/index.html.
- Grisanti L. A. (2018). Diabetes and Arrhythmias: Pathophysiology, Mechanisms and Therapeutic Outcomes. Frontiers in physiology, 9, 1669. https://doi.org/10.3389/fphys.2018.01669.