Type-1 diabetes occurs when people are not able to produce any insulin after the cells in the pancreas have been damaged, thought to be an autoimmune response.
Sixty-five percent of diabetics die from heart attack and stroke, and people with diabetes are reported to have a two to four higher chance of developing cardiovascular disease.
The research, published in the Journal of the American College of Cardiology (Vol. 47, pp. 598-604), studied 11 healthy non-diabetics with an average age of 25, and 11 type-1 diabetics with an average age of 36. Both sets of volunteers ate a standard meal (12 kcal per kg body weight) the night before the examination.
Plasma lactate, insulin and blood flows were found to be similar between diabetics and non-diabetics. However, the researchers recorded significantly higher levels of free fatty acids (0.6 versus 0.2 micromoles per gram per minute), myocardial fatty acid utilisation (MFAU) (213 versus 57 nanomoles per gram per minute), and myocardial fatty acid oxidation (MFAO) (206 versus 50 nanomoles per gram per minute) in the diabetics versus non-diabetics.
Myocardial glucose utilisation (MGU) for diabetics was about half that of non-diabetis, 207 versus 403 nanomoles per gram per minute.
This result indicates that the heart muscle of type-1 diabetics relies heavily on fat and very little sugar for its energy needs.
"The diabetic heart's over dependence on fat could partly explain why diabetic patients suffer more pronounced manifestations of coronary artery disease," said lead researcher Robert Gropler from the Washington University School of Medicine in St Louis.
The scientists suggest that the increased levels of blood fat levels are responsible for the abnormal heart metabolism, and that by decreasing fat intake patients could reduce the burden of fat metabolism on the heart.
"We believe it's not enough to control blood glucose in diabetes. You also have to target fat delivery to the heart," said Gropler.
"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," he said.
The researchers have since started a larger study of heart muscle metabolism in type-2 diabetics, a form of the condition that affects many more people than type-1.
A healthy, low-fat diet has recently been championed by the Pritikin Center in Florida. Led by Dr. R. James Barnard from UCLA, the study showed that type-2 diabetics could lose weight and control their blood sugar levels by diet alone.
By 2025 the prevalence of both types of diabetes is estimated to increase by 20 per cent in Europe and a whopping 50 per cent in the US. According to WHO guesstimates between 2.5 and 15 per cent of a nation's annual health budget is spent on diabetes care.