paths to a cure: metabolic control

Treatments that continually monitor the body's blood sugar levels and automatically respond with the correct dose of insulin would significantly enhance metabolic control. JDRF research is focused on demonstrating that advanced monitoring tools improves the health of people with diabetes, and on developing technologies that link insulin pumps and continuous glucose monitors. Such a "closed loop" system would, in effect, be an artificial pancreas.

Metabolic Control: Recent Key Advances, Fall 2008

Landmark Study Demonstrates That CGM Use Improves Blood Sugar Control
In September 2008, JDRF announced results from its Continuous Glucose Sensor Human Clinical Trial, the largest study of the effectiveness of continuous glucose monitors in the world to date. The trial has found that people with type 1 diabetes who used continuous glucose monitoring (CGM) devices to help manage their disease experienced significant improvements in blood sugar control.

"These results are very important, because they show that continuous glucose monitors are more than simply devices of convenience for people with diabetes - they are tools that can substantially improve blood sugar control when used regularly," said Dr. Aaron Kowalski, the Program Director for Metabolic Control. "Based on the findings of previous studies, better control of glucose levels over the long term can be expected to translate to a lower risk of complications for people with type 1 diabetes."

The CGM study was a randomized, controlled trial involving 322 patients between the ages of 8 and 72 at 10 sites nationwide. Patients were assigned to use either CGM or to a control group using standard blood sugar monitoring, and were followed for 26 weeks to assess effects on blood sugar control, principally assessed by measurement of the HbA1c level.

The study found that improvements in blood sugar control were greatest for CGM patients 25 years of age or older. It also found that CGM use varied with age, averaging at least six days a week over the course of the trial in 83% of the patients 25 years and older, but dropping off to 30% in the 15-to-24-year-olds and 50% in the 8-to-14-year-olds. The lower levels of regular CGM use among children and teenagers underscore the importance of continued research into a closed-loop artificial pancreas.

FDA Approves In Silico Model of the Artificial Pancreas
In a groundbreaking development, the U.S. Food and Drug Administration (FDA) has approved an in silico model of diabetes - a computer simulator - as a pre-clinical testing tool for closed-loop research at the seven JDRF Artificial Pancreas Consortium sites. The simulator, which allows consortium researchers to "plug-and-run" their algorithms in a controlled virtual environment, will facilitate the development of new algorithms that will be key to the development of an artificial pancreas. The simulator will enable researchers to:

• Test and refine artificial pancreas algorithms quickly
• Allow for computer-based algorithm comparisons;
• Eliminate the need for animal testing, allowing investigators to focus instead on in-hospital human clinical trials, saving time and considerable expense.

Because the simulator is now FDA-approved, the process of receiving regulatory approval for human trials of closed-loop systems will be faster and more clearly defined - a significant achievement that should also accelerate the development and possible commercialization of a closed-loop artificial pancreas.

Collaborators in developing the simulator were Dr. Claudio Cobelli of the University of Padova, a pioneer in the mathematical modeling of glucose metabolism, who laid the foundation for building the in silico platform, and Dr.Boris Kovatchev, principal consortium investigator at the University of Virginia, who took the lead for the consortium in developing and obtaining approval for the device.

JDRF Consortium Develops Artificial Pancreas Algorithms - and Expands
The JDRF Artificial Pancreas Consortium - comprising top diabetes scientists, doctors, and engineers at seven institutions in the United States and England - has been working to develop and test the sophisticated algorithms that will enable continuous glucose monitors to "communicate" with insulin pumps in order to automatically control glucose levels in a variety  of circumstances and types of people. The consortium has already created various algorithms tailored for the overnight hours, mealtime, exercise, patient type, and various hormones. This is a key advance, since the development of an artificial pancreas is dependent on the development of these algorithms.

The consortium is expanding to three additional sites in Italy, France and Israel, which should further speed progress toward its goals.

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