The combination of diabetes and coronary artery disease is an all-too-common double whammy. Diabetes is an important risk factor for heart disease, and obesity can lead to both of these conditions. Diabetes and heart disease become increasingly common as people grow older, so it also isn't surprising that the number of elderly Americans with both diseases is growing steadily.

What makes this combination particularly worrisome is that virtually every study shows that people with heart disease and diabetes have at least a two- to four-fold increase in risk for cardiovascular complications. Among patients who have heart attacks, the chances of dying are two to three times greater in diabetics. Finally, people with diabetes who undergo balloon angioplasty seem to have much poorer outcomes than non-diabetics.

All of these concerns make the accurate diagnosis of coronary artery disease especially important for individuals with diabetes, but frequently this condition goes undetected. Why is the heart disease overlooked? Often heart-disease symptoms in diabetics are mild or absent. And because many of these people are not active physically, they do not do enough strenuous exercise to bring out symptoms such as angina.

The benefits of early detection of coronary heart disease among diabetics are considerable. Research has shown that aggressive treatment of high cholesterol levels, high blood pressure, and other risk factors can help prevent heart and kidney problems. Physicians usually avoid beta blockers when treating high blood pressure in diabetics, but this therapy is so valuable for people with coronary artery disease that these drugs may warrant serious consideration in diabetic patients with known heart disease.

The American College of Cardiology and the American Diabetes Association recently issued a set of recommendations regarding the diagnosis of coronary heart disease in people with diabetes. This expert panel indicated that physicians should have a low threshold for using exercise tests and other techniques to detect heart disease in their diabetic patients. It urged consideration of stress testing in such patients with any chest pain symptoms, even if these symptoms were not typical of angina and were accompanied by a normal electrocardiogram.

The panel did not recommend routine exercise testing for people with diabetes who also have:

• no symptoms of heart disease
• a normal electrocardiogram
• and one or fewer risk factors for coronary heart disease
  (these include cholesterol abnormalities, hypertension, smoking, family history of early heart disease, and evidence of protein in the urine)

The guidelines strongly recommend exercise testing for people who have diabetes and any of the following:

• two or more risk factors for heart disease
• evidence of atherosclerosis in other blood vessels (such as the arteries supplying the brain or the legs)
• a sedentary lifestyle and plans to start a vigorous exercise program
• or even minor abnormalities on the electrocardiogram

The guidelines encouraged comprehensive evaluation of any patient with a positive stress test. Even if the test showed no evidence of heart disease, the expert panel recommends close follow-up when patients have four to five heart-disease risk factors, with exercise testing every one to two years. Otherwise, repeat exercise testing in three to five years was encouraged. It is also especially important for diabetics with heart disease to work with their doctors to control those factors that increase the risk of complications. Such steps include maintaining a healthy blood pressure and reducing LDL cholesterol. The importance of this has been shown by a recent study of coronary patients with diabetes and high LDL cholesterol. Patients who had their LDL lowered by a statin had 55% fewer heart attacks and heart-disease deaths over a five year period.

These guidelines reflect the belief that exercise testing and other technologies used to detect coronary disease may be underused in people with diabetes. The recommendations would greatly increase the use of these tests in diabetics who have few or no symptoms of heart disease. However, the potential benefits of early detection and treatment of heart disease might help reduce the toll that this combination currently takes.