By Erika Gebel, PhD
There has been plenty of good news about diabetes and heart health. For example, deaths from heart attack and stroke in adults with diabetes fell by a remarkable 40 percent between 1997 and 2006, according to a study published last June in Diabetes Care. Still, cardiovascular disease remains America’s No. 1 killer, and for people with diabetes the risk is doubled. So, even with advances in care, people need to stay on top of their game.
The clear gains are attributed, in part, to improvements in managing cardiovascular disease risk factors. In other words, knowing what puts you on the path to a heart attack is half the prevention battle. February is American Heart Month and a great time of year to learn about ways to stop cardiovascular disease in its tracks.
Go With the Flow
A big misconception about cardiovascular disease is that it’s all about the heart. Yes, “cardio” does mean heart, but “vascular” refers to blood vessels, so cardiovascular disease is really a condition that affects the heart and the blood vessels. Of course, the heart’s job is to pump blood throughout the body, linking the organ to all blood vessel disease.
“There are very few places in our body that don’t have blood vessels,” says Mikhail Kosiborod, MD, a cardiologist at St. Luke’s Health System in Kansas City, Mo. “For the tissues and organs of the body to work properly, you need blood flow.” Like other organs, the brain needs a constant supply of blood to stay properly nourished. When that supply gets cut, the result is a stroke, which is now considered to be a “component of cardiovascular disease,” says Kosiborod. “We used to think it was a neurological problem.”
When blood flow is choked off in the arms or legs (this occurs much more often in the legs), that’s peripheral vascular disease. This type of cardiovascular disease can lead to foot ulcers, amputations, and other complications.
Symptoms of Cardiovascular Disease
Chest pain (angina)
Shortness of breath
Weakness or dizziness
Cardiovascular disease also includes several different heart conditions caused by problems in the blood vessels. The most common is called either coronary heart disease or coronary artery disease. Coronary heart disease is caused by atherosclerosis, a narrowing of blood vessels that supply the heart with blood. Atherosclerosis occurs when fatty gunk called plaque builds up along the insides of an artery’s walls. If there’s a sudden large reduction in blood flow, usually from a blood clot that forms on the surface of the plaque, the result is a heart attack. Similarly, if atherosclerosis and occlusion occur in the blood vessels that deliver blood to the brain, cutting off the blood supply, the result is an ischemic stroke, the most common type of stroke. (Thirteen percent of strokes are hemorrhagic strokes, which are caused by a burst blood vessel in the brain.)
Another type of cardiovascular disease is heart failure, a condition characterized by a heart that is too weak to pump enough blood around the body. There is also arrhythmia, an abnormal heartbeat that can be deadly in extreme cases. Some people develop problems with their heart valves, the muscles that pinch off the heart’s chambers to maintain proper flow.
Secrets of the Heart
The sad fact is that many people don’t know they have cardiovascular disease until something bad happens. “The first manifestation can be a heart attack or stroke,” says Kosiborod. “Our goal as health professionals is to prevent that from happening.”
Go for the Goal
The American Diabetes Association recommends that people with diabetes reach these targets to maintain heart health.
Less than 7 percent for most people (agree on your specific target with your doctor)
♦ For people with cardiovascular disease: less than 70 mg/dl
♦ For people without cardiovascular disease: less than 100 mg/dl
Less than 140/80 mmHg for most people (agree on your specific target with your doctor)
To check for cardiovascular risk, doctors rely on blood tests taken at least once a year as well as blood pressure checks at every office visit. “Stroke is largely related to blood pressure, and coronary events are more related to cholesterol,” says Michael Farkouh, MD, chair of the Peter Munk Center of Excellence in Multinational Clinical Trials at the University of Toronto and a cardiologist at the Mount Sinai Cardiovascular Institute in New York. The most critical measures for monitoring risk for heart disease in people with diabetes are A1C (average blood glucose over the previous two to three months), LDL (“bad”) cholesterol, and blood pressure. (For healthy targets, see “Go for the Goal,” right.)
Screenings and Diagnosis
Just because people have risk factors, however, doesn’t mean they have cardiovascular disease. Some doctors may employ a stress test to check for coronary heart disease in people with symptoms. The patient runs on a treadmill or rides a bike while the doctor checks for heart abnormalities or symptoms of heart disease, such as chest pain. The idea behind the stress test is that physical exertion strains the heart and can bring any hidden issues to the surface. But it’s not perfect. To tell if a person actually has coronary heart disease in the absence of a heart attack, the key is finding the atherosclerosis. But how do you check for atherosclerosis? “That’s the million-dollar question,” says Kosiborod, citing a tremendous ongoing effort among scientists to develop and validate such tests.
Farkouh says “there may be emerging techniques that look for atherosclerosis.” For example, a test called the coronary calcium scan checks the arteries for calcium, which is a significant component of plaques. People with a high calcium score are more likely to have a heart attack or stroke, but it still isn’t clear whether aggressively treating risk factors such as cholesterol in people with high calcium scores alone (without other risk factors such as diabetes) can prevent deaths from cardiovascular disease. “We just don’t know yet what it means,” says Farkouh.
It’s important to keep in mind that heart disease isn’t just a man’s disease. Women are about as likely to have heart attacks as men, and their risk of dying after a heart attack is actually higher. Researchers are just beginning to explore the gender gap in heart health, but studies suggest a number of reasons for the disparity. For example, heart attack symptoms can vary between women and men. Women often experience gastrointestinal discomfort with a heart attack, while men are more likely to have the classic symptom of chest pain. Another factor may be stereotypes that lead some doctors to ignore or misdiagnose symptoms of heart disease in women.
What You Can Do
Checking and treating cardiovascular disease risk factors, early and often, is the primary approach for people with either type 1 or type 2 diabetes. Start with smoking. Smokers are two to three times more likely to develop coronary heart disease than nonsmokers. Losing weight and getting more exercise may also help people with diabetes control heart disease risk factors. (Recent findings suggest, however, that weight-loss programs may not provide additional benefits on top of controlling traditional risk factors such as blood pressure and cholesterol.) “What we know for sure is that patients who lead healthy lifestyles tend to do a lot better than patients who don’t,” says Kosiborod.
Diabetes itself is a risk factor for cardiovascular disease. The relationship between the conditions isn’t fully understood, but it may have to do with how chronically high levels of glucose in the blood damage the blood vessels. Meeting individual blood glucose goals is a critical part of self-care for people with diabetes to help stave off complications, including cardiovascular disease. Farkouh notes that blood glucose may play an especially great role in preventing heart disease in people with type 1. “Glycemic control provides more benefit in type 1s than in type 2,” he says. Another important difference, he says, is that people with type 1 tend to get heart disease earlier in life than people with type 2.
For people with high “bad” cholesterol, avoiding foods with saturated fat, trans fat, and cholesterol while adding foods with omega-3 fatty acids may help bring those levels down. Experts recommend statins for people with diabetes who have too high LDL cholesterol or diagnosed cardiovascular disease, or who are over the age of 40 and have additional risk factors, such as high blood pressure. “Diet is important, but statins are more effective,” says Farkouh.
If lifestyle changes can’t quickly reduce blood pressure to target levels, doctors will probably prescribe an ACE inhibitor or an ARB, powerful blood pressure medications that can also improve kidney health. If these drugs don’t work or aren’t well tolerated, doctors can choose from other classes of blood pressure medications.
More than one medication is often needed to control blood pressure.
Sometimes medications aren’t enough. For people with severe cardiovascular disease, doctors may recommend an invasive procedure such as bypass surgery (creating an alternate route for blood to travel around a blockage, using a blood vessel from elsewhere in the body) or angioplasty (inserting a balloon catheter with or without a stent to open a clogged artery) to protect a patient from heart attacks and strokes. Candidates for these procedures typically have debilitating chest pain, a history of heart attack or stroke, or evidence of severe blockages in major arteries.
Farkouh was coauthor of a November 2012 study in the New England Journal of Medicine that found that for people with diabetes and multiple clogged arteries, bypass surgery prevents more heart attacks and deaths than angioplasty. The study “showed that bypass is clearly preferred in patients with diabetes,” says Kosiborod. This is just the latest in a long line of medical breakthroughs for people with diabetes that have made their hearts healthier and their lives longer.