When we talk about heart disease risk factors, blood sugar often takes a back seat to cholesterol and blood pressure. However, there’s a profound and intimate connection between blood sugar levels and heart health.
Dace Trence, MD, professor-emeritus of medicine at the University of Washington in Seattle and president of the American Association of Clinical Endocrinology, says high blood sugar has two direct negative effects on the health of the cardiovascular system:
- Inflammation This immune system response involves the “increased production of components in the blood system that increase the risk of developing cardiovascular disease, such as cytokines or inflammatory modulators,” says Dr. Trence.
- Oxidative Stress This imbalance between harmful free radicals and protective antioxidants “leads to damage to cells,” she says.
Both of these factors increase the risk of developing cardiovascular diseases, according to Trence.
High blood sugar also triggers the excessive production of insulin, which enacts a harmful cycle known as insulin resistance. With insulin resistance, a defining feature of both type 2 diabetes and prediabetes, your body becomes less sensitive to the hormone insulin, which forces your pancreas to produce even more of it.
Insulin is best known for regulating blood sugar, but it also has wide-ranging effects on heart and blood vessel health. Larger amounts of insulin in the bloodstream can lead to dysfunctional changes, such as thicker artery walls, enlarged heart muscles, and tighter and stiffer blood vessels.
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Through these mechanisms, insulin resistance can also spike traditional heart health risk factors, such as blood pressure and cholesterol.
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Some experts even suggest that type 2 diabetes and cardiovascular disease are essentially different manifestations of the same illness.
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A related theory groups shared diabetes and heart health risk factors together under the term “metabolic syndrome.”
“Metabolic syndrome is a secondary effect of having long-term poor dietary habits and being sedentary,” says Neil Yager, DO, a cardiologist at Albany Medical Center in New York and president of the board of directors of his local American Heart Association chapter. If you have prediabetes or type 2 diabetes, you have at least one element of metabolic syndrome.
