Diabetic hearts make unhealthy switch to high-fat dietFebruary 06, 2006The high-fat "diet" that diabetic heart muscle consumes helps make cardiovascular disease the most common killer of diabetic patients, according to a study done at Washington University School of Medicine in St. Louis. The study will appear in the February 7 issue of the Journal of the American College of Cardiology and is now available online. Sixty-five percent of people with diabetes die from heart attack or stroke. When the researchers investigated fuel consumption in heart muscle, they found that heart muscle of type 1 diabetic patients relies heavily on fat and very little on sugar for its energy needs. In contrast, heart muscle in non-diabetics doesn't have this strong preference for fat and can use either sugar (glucose) or fat for energy, depending on blood composition, hormone levels or how hard the heart is working. "The diabetic heart's overdependence on fat could partly explain why diabetic patients suffer more pronounced manifestations of coronary artery disease," says senior author Robert J. Gropler, M.D., professor of radiology, medicine and biomedical engineering and director of the Cardiovascular Imaging Laboratory at the Mallinckrodt Institute of Radiology at the School of Medicine. "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." Compared to non-diabetics, diabetic patients often have larger infarctions and suffer more heart failure and sudden death when the heart experiences an ischemic (low-oxygen) event. In addition, when the diabetic heart burns fat, it accumulates reactive oxygen molecules that interfere with the fuel consumption mechanism and encourage the accumulation of fats in the muscle cells. This can lead to increased inflammation, cell death and heart dysfunction. The diabetic heart's reliance on fat molecules for energy was previously observed in experiments using diabetic animals. But this is the first time researchers have confirmed that burning of fatty acids in the heart muscle is increased in humans with diabetes. In this study, 11 healthy, non-diabetic people were compared to 11 otherwise healthy people with type 1 diabetes. The researchers found that the diabetic patients had much higher levels of fats in their blood and had an increased uptake of fatty acids into heart muscle cells. The cells of diabetic hearts not only absorbed more fat, they also burned a higher percentage of the fats they took in. As a result, diabetic heart muscle used about half as much glucose and four times more fat for energy than the hearts of non-diabetics. The researchers are now engaged in a larger study of heart muscle metabolism in type 2 diabetics. Patients in the study are 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 accruing patients, and people with type 2 diabetes who would like to participate can call 314-362-8608. If the increased blood-fat levels are confirmed to be responsible for the dysfunctional metabolism of diabetic heart muscle, reducing fat levels may become an important way to decrease illness and death from cardiovascular disease in diabetics, according to the authors. "We believe it's not enough to control blood glucose in diabetes," Gropler says. "You also have to target fat delivery to the heart. If you decrease the 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 heart health." Washington University School of Medicine |
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| Related High-fat Diet Current Events and High-fat Diet News Articles Think what you eat: Studies point to cellular factors linking diet and behavior New research released today is affirming a long-held maxim: you are what you eat - and, more to the point, what you eat has a profound influence on the brain. UT Southwestern study shows how substance in grapes may squeeze out diabetes A naturally produced molecule called resveratrol, found in the skin of red grapes, has been shown to lower insulin levels in mice when injected directly into the brain, even when the animals ate a high-fat diet. CHEO RI study uses sophisticated genetic engineering to improve insulin-producing beta cells One of the biggest mysteries about diabetes is why specialized cells in the pancreas stop secreting insulin, which the body needs in order to store glucose from food. Monash research cautions against use of anti-oxidants An international team of scientists, led by Monash University researchers, has found that anti-oxidants commonly touted for their health-promoting benefits, could contribute to the early onset of Type 2 diabetes. High-fat diet impairs muscle health before impacting function Skeletal muscle plays a critical role in regulating blood sugar levels in the body. But few studies have comprehensively examined how obesity caused by a high-fat diet affects the health of muscle in adolescents who are pre-diabetic. Scientists find obesity alone does not cause arthritis in animals The link between obesity and osteoarthritis may be more than just the wear and tear on the skeleton caused by added weight. Ice cream may target the brain before your hips, UT Southwestern study suggests Blame your brain for sabotaging your efforts to get back on track after splurging on an extra scoop of ice cream or that second burger during Friday night's football game. Exercise Minimizes Weight Regain By Reducing Appetite, Burning Fat, And Lowering 'Defended' Body Weight Exercise helps prevent weight regain after dieting by reducing appetite and by burning fat before burning carbohydrates. UCLA scientists uncover immune system's role in bone loss Got high cholesterol? You might want to consider a bone density test. A new UCLA study sheds light on the link between high cholesterol and osteoporosis and identifies a new way that the body's immune cells play a role in bone loss. Do high-fat diets make us stupid and lazy? Short-term memory getting worse? Exercise getting harder? Examine your diet. New research published online in The FASEB Journal showed that in less than 10 days of eating a high-fat diet, rats had a decreased ability to exercise and experienced significant short-term memory loss. More High-fat Diet Current Events and High-fat Diet News Articles |
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