TUESDAY, Feb. 7, 2006 (HealthDay News) -- The heart muscle of people with diabetes relies on fat as an energy source, researchers report. The finding could explain why 65 percent of people with diabetes die from heart attack or stroke, they add.
A team at Washington University School of Medicine in St. Louis compared the heart function of 11 type 1 diabetics and 11 non-diabetics. They found that the cardiac muscle of people with diabetes is heavily dependent on fat for energy and relies very little on the usual energy source, glucose (sugar).
In comparison, the heart muscle of people without diabetes does not have a strong preference for fat and can use either glucose or fat as a fuel source, depending on the person's blood composition, hormone levels or how hard their heart is working.
"The diabetic heart's overdependence on fat could partly explain why diabetic patients suffer more pronounced manifestations of coronary artery disease," study senior author Dr. Robert J. Gropler, a professor of radiology, medicine and biomedical engineering, said in a prepared statement.
"The heart needs to use much more oxygen to metabolize fats than glucose, making the diabetic heart more sensitive to drops in oxygen levels that occur with coronary artery blockage," said Gropler, who is also director of the cardiovascular imaging laboratory at the Mallinckrodt Institute of Radiology at the School of Medicine.
"We believe it's not enough to control blood glucose in diabetes. You also have to target fat delivery to the heart. If you decrease fat delivery through a combination of diet, exercise and drugs, you'll improve the heart's ability to use other energy sources, which will improve health," he said.
The findings are currently online and appear in the February 7 print issue of the Journal of the American College of Cardiology.
And the same researchers are now involved in a larger study of heart muscle metabolism in type 2 diabetics. Patients in the study will be divided into two groups with one group receiving standard therapies to normalize blood glucose levels and the other group receiving additional therapies designed to decrease the amount of fat in the blood.
The study is still recruiting patients, and people with type 2 diabetes who would like to participate can call 314-362-8608.
The U.S. National Diabetes Information Clearinghouse has more about diabetes, heart disease and stroke.