February 08, 2010 Stephanie Lachapelle for Diabetes1
A study funded by the Juvenile Diabetes Research Foundation at the University of Cambridge, United Kingdom, shows the success of a closed-loop artificial pancreas system in maintaining blood glucose levels in target range in children and young adults. This is just one advance on the long road toward a cure for type I diabetes.
In those 3 million Americans with type I diabetes, the immune system kills off the cells of the pancreas that produce insulin, a protein hormone necessary to break food down into individual units of energy. People with type I diabetes monitor their blood glucose levels several times throughout the day, and inject insulin to maintain a healthy glucose level. There is presently no cure for type I diabetes, and good blood glucose control is the key to reducing the risk of developing long-term complications like blindness and kidney disease. Overnight control of blood glucose levels remains in the top of the list of concerns for parents of type I children. The artificial pancreas holds promise for quelling the fears of these parents and reducing the number of hospitalizations due to hypoglycemia, a condition where the blood glucose levels drop dangerously low, during the night.
The artificial pancreas is essentially an external loop of a controlled glucose monitor (CGM), which continuously monitors the blood glucose levels and signals an insulin pump to release insulin when necessary. The closed loop is controlled by a sophisticated computer program set to determine the insulin dosage based on the blood glucose level while the patient sleeps.
The trials tested the efficacy and safety of the artificial pancreas in an overnight hospital setting with children between ages 5 and 18 years old with type I diabetes. Researchers tested the system in three typically worrisome situations-simple nighttime blood glucose control, nighttime control after a large meal, and nighttime control after exercise. In the simple nighttime situation, participants spend 52% of the night in the target range of blood glucose measurement, between 70 mg/dL and 140 mg/dL, compared to only 39% without the aid of the device. Comparable results were found after a large meal. The closed loop system show the most significant improvement in blood glucose control during the night after moderate exercise, increasing time spent in the target range from 48% to 78%. Overall, the pooled data indicates that blood glucose levels were 61% in target, and increased to 75% in target after midnight, when the system took full effect.
Ultimately, the study indicates that participants spent twice as much time within the target blood glucose level when regulated with the closed loop system, compared to conventional regulation, and incidence of low blood sugar was minimized.
"These studies show that automated systems not only can help people manage diabetes by maintaining good control, they will also improve quality of life for the people with type 1 diabetes and their families by lowering the risk for hypoglycemia," said Dr. Roman Hovorka, from the Institute of Metabolic Science at the University of Cambridge. “These results suggest that closed-loop devices may be able to significantly lower the patient's risk of developing complications later in life by reducing or even overcoming the burden of hypoglycemia."
The ultimate goal of the Artificial Pancreas Project, funded by the JDRF, is to speed the development of “automated diabetes management systems”. Researchers hope to develop an advanced system that would house a sophisticated computer program to automatically deliver the right amount of insulin.
more Feature Stories
