Type 1 diabetes mellitus, or juvenile diabetes, generally has a sudden onset in childhood and is caused by destruction of the pancreas by the body’s immune cells. Under normal conditions, the pancreas releases the hormone insulin in response to the level of glucose in the blood, or blood sugar. To avoid high blood sugar levels, or hyperglycemia, type 1 diabetics have a daily routine of blood sugar measurement and insulin injections.
Pancreas Dysfunction and the Insulin-Glucose Cycle
In type 1 diabetes, the insulin-producing islet cells of the pancreas are destroyed, leading to a lack of insulin production and increased blood glucose levels. Untreated hyperglycemia can result in the body breaking down fats for energy, resulting in the accumulation of ketones in the blood. The body cannot handle these byproducts, and the condition can lead to diabetic coma, followed by death. Throughout the day, type 1 diabetics inject insulin based on their blood glucose level, which they measure with a glucose meter using a small blood sample, usually from the fingertip or arm.
However, another hormone released by the pancreas, glucagon, controls the release of stored glucose when the blood sugar levels drop below useful levels. Hypoglycemia can occur if too much insulin is used by diabetics, who cannot quickly recover because the pancreas does not function properly. Glucagon injections are sometimes used to counter extreme fluctuations. A key to freeing type 1 diabetics from this endless prick-measure-inject-measure-inject lifestyle is an artificial pancreas that can continuously measure and release in real-time.
Previous Steps Toward an Artificial Pancreas
Researchers and doctors have been working towards an artificial pancreas for decades. In the 1970s, a surgically placed insulin pump was approved for type 1 diabetics as an alternative to injections. After measuring their blood sugars, the patient can externally trigger the pump to release insulin from its location inside their abdomen. A complimentary device was approved in 2006 – a continuous glucose monitor. The monitor is a sensor surgically placed under the skin to monitor glucose levels, avoiding pricks and meter measures. A second model was approved in 2008, and a third is due to hit the market in 2010 or 2011. However, biotech companies have been cautious to approach integrating the two devices due to the liability involved in a patient relying on the communication between them.
Recent Work Towards a Robotic Pancreas
Dan Hurley wrote in the April 19, 2010 edition of the online magazine Wired (accessed July 19, 2010) about Jeffrey Brewer, the co-founder of internet sites CitySearch and Overture, and his mission to build a robotic pancreas that acts like a real pancreas with automated glucose measurements and insulin release. Brewer is pursuing the technology for his young son, who has type 1 diabetes. The research into the software to connect the insulin pump and glucose sensor began at Yale in 2008. Seventeen teenagers volunteered to pilot test the devices and compare them to manual blood sugar maintenance. The researchers found that the computer was much better at regulating their blood glucose levels. A research group at the University of Virginia used computer simulations to further test the device, and they began the largest clinical trial of the device in the U.S., France, and Italy in April 2009. Now in 2010, the robotic pancreas is not yet approved in the U.S. – the FDA is awaiting further research results on the device’s shutoff feature, but the biotech company Medtronic obtained approval to market such a device in some European countries in June 2009. The FDA is working to accelerate the approval process on the robotic pancreas as part of the Critical Path Initiative.
For more information on surgically implanted insulin control devices, visit the Children With Diabetes website.
Alicia Mae Prater - Alicia received her doctorate in Experimental Pathology in 2007. She has been a freelance writer and scientific editor since 2008.
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