NEW YORK, April 14, 2010 -- In a clinical trial that studied the benefits of a unique artificial pancreas system utilizing two hormones to control blood sugar, patients were able to achieve near-normal sugar levels for more than 24 hours without hypoglycemia, or low blood sugar. The results from the study, co-funded by the Juvenile Diabetes Research Foundation, are reported today in the journal Science Translational Medicine.
Researchers from Boston University and Massachusetts General Hospital tested the safety and efficacy of a novel closed-loop system that incorporated the use of glucagon, in addition to insulin. Glucagon is a naturally occurring hormone that raises blood sugars in response to hypoglycemia and is impaired in people with type 1 diabetes. The addition of glucagon to the closed-loop system was designed to more closely mimic the physiology of a person without diabetes. Currently, glucagon is not used as a routine part of type 1 diabetes therapy, but is used in large doses to treat people in low blood sugar emergencies.
Maintaining recommended blood sugar levels is a major challenge for people with type 1 diabetes because of the possibility of blood glucose dropping dangerously low, which can lead to seizures, coma, and in some cases death.
The system combined a sensor placed into a vein to monitor glucose levels and infusion pumps that were controlled by a sophisticated computer program that determined insulin and glucagon dosage based on blood glucose levels.
According to Edward Damiano, Ph.D., associate professor of Biomedical Engineering at Boston University and senior author of the study, the system was designed to counteract moderate drops in blood sugar with minute doses of glucagon spread out throughout the day, similar to what the body does in people without diabetes.
The trial involved 11 adult subjects with type 1 diabetes, who wore the system for 27 hours. The participants ate three standardized, high-carbohydrate meals and slept overnight at the hospital. In the first phase of the study, six participants achieved average blood glucose levels (140 mg/dl) in the target range with the artificial pancreas system without hypoglycemia, but other participants had some hypoglycemia. In a second phase of the study, the researchers adjusted the system to reflect a slower insulin absorption rate and none of the participants experienced significant hypoglycemia in repeat experiments. Although average blood sugar levels were slightly higher,in the repeat experiments, they still remained near the target range.
Overall, the research team demonstrated that glucagon consistently helped reverse the downward slope of blood-glucose levels. "This study is proof of principle that the use of glucagon in artificial pancreas systems can be beneficial and important in lowering the risk of low blood-sugar emergencies," said Aaron Kowalski, Ph.D., Assistant Vice President of Metabolic Control at JDRF and Director of the JDRF Artificial Pancreas Project. "In addition, it also provides us with important insight about the role that the rate of insulin absorption will play in customizing algorithms that will drive these systems so that they function optimally."
Type 1 diabetes is an autoimmune disease in which the immune system attacks and kills the cells in the pancreas that produce insulin, a hormone that enables people to convert food into energy. Although the glucagon-producing cells are not destroyed, glucagon is no longer released in response to low blood sugars, leaving people with type 1 diabetes vulnerable to hypoglycemia. (Continue a ler aqui)
Sem comentários:
Enviar um comentário