For years, a high-fat diet has been linked to heart disease. But studies also show that sugar isn't so sweet when it relates to your heart health.
According to the American Heart Association, adults with diabetes are 2-4 times more likely to suffer from heart disease or stroke than adults without diabetes. In fact, the link between heart disease and diabetes is so well-established that the American Heart Association identifies it as 1 of the 7 major modifiable risk factors for cardiovascular disease.
"Diabetes is considered a cardiovascular risk equivalent. So essentially, we treat patients with diabetes the same way we would treat someone with cardiovascular disease," says Jared Kvapil, MD, cardiologist at The University of Kansas Health System.
Diabetes is a condition that results in higher than normal blood sugar levels. This may be because the body doesn't make enough of the hormone insulin (type 1), or because the body doesn't use insulin properly (type 2).
Insulin moves sugars out of the bloodstream into cells to use as fuel or to store as energy. Without this process, blood sugars rise to unhealthy levels. Excess glucose in the blood impairs several organs throughout the body, including the heart, and damages nerves and blood vessels.
"The blood vessels of diabetics don't react the same way as they do in nondiabetics," Dr. Kvapil says. "Normally, blood vessels self-regulate to dilate or constrict when they need to. However, that mechanism seems to be impaired in diabetics."
High blood glucose can also cause plaque to accumulate inside the blood vessel walls, thereby inhibiting normal blood flow. Dr. Kvapil mentions that diabetics are known to have "increased platelet activation." This means their blood clots more easily than a nondiabetic's, resulting in a greater risk of heart attack and stroke.
What diabetics and heart patients share
In addition to high blood sugar levels, diabetics typically have additional risk factors usually found in people with heart disease. According to Dr. Kvapil, diabetics and heart patients often share certain characteristics, including:
- High blood pressure (hypertension)
Diabetics and people with heart disease usually suffer from high blood pressure. This means blood is pumping through the heart and blood vessels too forcefully. Over time, this can cause the heart to weaken and may result in heart failure. Uncontrolled hypertension has also been shown to increase the risk of kidney disease, retinopathy (damaged blood vessels in the eye) and cognitive diseases such as Alzheimer's.
- High triglyceride levels
Triglycerides are fatty substances found naturally in the blood that are made in the liver and also found in food. After eating, your body converts excess calories into triglycerides, which are then stored in fat cells and later released into the blood stream for energy between meals. High triglyceride levels are thought to contribute to hardening of the arteries and thickening of the artery walls, a condition known as atherosclerosis. This leads to an increased risk of heart disease and stroke.
- High cholesterol
Cholesterol is a fat-like substance in the blood that, like triglycerides, is produced in the liver and found in some foods. There are two types of cholesterol: low-density lipoprotein (LDL or "bad" cholesterol), and high-density lipoprotein (HDL or "good" cholesterol). HDL cholesterol removes cholesterol from the blood, preventing plaque formation. When levels of HDL are low, this protective benefit is lost. Similarly, too much LDL cholesterol can cause plaque to accumulate in the arteries.
Being overweight or obese puts you at a higher risk for developing diabetes and heart disease because it often results in elevated blood pressure, high cholesterol and excess triglycerides in the blood. Obesity is defined as having too much body fat, especially around the waist, and a body mass index higher than 30. Individuals who are overweight have a BMI of 25-29.9.
Waist circumference is also an important indicator of health. Research has shown that even individuals of normal weight are more at risk for heart disease and diabetes if their body fat is primarily concentrated in the abdomen. The National Institute of Diabetes and Digestive and Kidney Diseases recommends men have a waist circumference of no more than 40 inches and women no greater than 35 inches.
Managing diabetes and reducing your risk
Both diabetes and heart disease can be managed with a combination of medical therapies and lifestyle changes. Because diabetes and heart disease share many common risk factors, the guidelines for prevention and treatment often overlap.
"We really have to be aggressive with cholesterol management. Anyone with diabetes should be on a higher potency statin medication," Dr. Kvapil says. "A baby aspirin may also be recommended, just as a preventive mechanism. Blood sugar needs to be controlled, and many diabetics will likely use insulin."
In addition to medical treatment, Dr. Kvapil stresses the significance of a healthy diet and exercise program.
"The number one thing people can do to reduce their risk is live a healthy, active lifestyle," Dr. Kvapil says. "Eat a diet that is carb-conscious and higher in fruits, vegetables and lean meat. Some sort of physical activity for 20-30 minutes a day would also be ideal. If you are smoking, quitting tobacco completely is strongly recommended."
Staying in control
A person is said to have "controlled diabetes" when their average blood glucose concentration, or A1C, is 6-7%. At this point, the risk of cardiovascular disease is reduced. However, individuals with controlled diabetes are likely at a slightly higher risk for developing heart problems than a nondiabetic. Additionally, Dr. Kvapil notes that the signs and symptoms of a heart condition can be different in diabetics and often go undetected.
"Diabetic patients will tend to present with atypical symptoms of heart disease," Dr. Kvapil says. "They may lack the classic symptoms we associate with cardiac events, like a heart attack, and they are more prone to silent ischemia than the general population."
Signs of a silent heart problem may include unexplained fatigue, dizziness, feeling light-headed, heart palpitations, racing or irregular heartbeats and shortness of breath with activities that were previously well tolerated. Dr. Kvapil advises both diabetics and nondiabetics to seek medical attention if these or any other unexplained symptoms suddenly arise.