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Diabetes: Can Sugar Break Your Heart?

Greg May, M.D.
February 05, 2022
Dr. Greg May

Can eating candy, doughnuts, cookies, and ice cream cause a heart attack?

Not quickly, but maybe with time, if you don't keep an eye on that bathroom scale.

Diabetes, or abnormally elevated blood glucose, can occur during childhood due to absent or markedly diminished insulin production by the pancreas, type 1 diabetes. More commonly in adults, diabetes is related to obesity. As a result, "insulin resistance" describes that insulin is produced but ineffective at keeping blood sugar in the normal range, type 2 diabetes.

People with diabetes have 2-4 times the risk of heart attack and stroke compared with nondiabetics. What is the link making people with diabetes more likely to develop these potentially fatal problems?
Vascular disease, atherosclerosis, or “hardening of the arteries," refers to the progressive growth of cholesterol plaques in the body's arteries. Coronary artery disease (CAD) refers to the gradual enlarging of cholesterol plaques that can develop in the coronary arteries, which supply blood to the heart. Cerebrovascular disease (CVD) refers to plaque development in arteries supplying the brain. Peripheral artery disease (PAD) refers to plaques in arteries supplying the extremities, more commonly involving the legs.

Diabetics typically have more vascular diseases than nondiabetics; more heart attacks, strokes, and amputations of the lower extremities. Diabetics frequently have hypertension, elevated blood pressure, high LDL (bad cholesterol), high triglycerides, and low HDL (good cholesterol).

CAD progresses faster, and cholesterol plaques get much larger much quicker with poorly controlled diabetes.

Cholesterol plaque growth is a complex and not entirely understood process but is generally due to the endothelium's malfunction, a one-cell thick inner lining of arteries. With poorly controlled diabetes, persistently high blood sugar, and elevated cholesterol, the endothelium loses its natural ability to keep the wall of the artery healthy, and cholesterol can leave the bloodstream, go under the endothelial layer and enter the wall of the artery. Cholesterol is perceived by white blood cells as foreign, similar to an attack from bacteria and viruses. The result leads to plaque growth (think of little mountains developing in the artery wall). As cholesterol plaques grow, with high blood sugar and high cholesterol, the inside of the artery is filled up with plaque; therefore, the usual channel for blood flow is gradually reduced. Reduced blood flow to the heart can cause chest pain and shortness of breath. Eventually, cholesterol plaques can rupture or crack, causing a blood clot. When a blood clot forms, the artery closes off, and blood flow stops. The result is a heart attack.

Diabetes, smoking, hypertension, elevated LDL (bad cholesterol), low HDL (good cholesterol), family history of premature CAD, obesity, and a sedentary lifestyle are all risk factors for CAD. Progression of cholesterol plaques can be slowed and stabilized by reducing your risk factors. Diabetes can be controlled by weight loss, exercise, and medications to normalize blood sugar. In addition, hypertension and high cholesterol respond favorably to the same.

Atherosclerosis, cholesterol plaque growth in our arteries, seems like an inevitable process as we age, but there is hope! Your decision to follow an improved lifestyle of a heart-healthy diet (at least most of the time), regular aerobic exercise, not smoking, and routine medical follow-ups for guidance controlling blood pressure and cholesterol management would pay dividends in reducing your risk in the future.

Dr. Greg May is an interventional cardiologist at MUSC Health – Cardiology in Florence. He is accepting new patients. For more information, or to make an appointment, please call 843-674-4787, or visit MUSC Health Florence Medical Center.