April 14, 2010 — Researchers have added a new element to the “artificialpancreas” that may help the 3 million Americans living with type 1 diabetesbetter control their blood sugar (glucose) levels and stave offdiabetes-related complications.
The new findings appear in Science Translational Research.
The hope is that an artificial pancreas will do what the pancreas cannot doamong people with type 1 diabetes: produce the hormone insulin.
Research on the development of an artificial pancreas has traditionallyfocused on delivery of insulin. But the new design introduces another hormonecalled glucagon to the equation.
People with type 1 diabetes do not produce any insulin, which is needed toregulate blood sugar levels. Glucagon is another hormone that is produced bythe cells in the pancreas to help control blood sugar levels. People withdiabetes do produce glucagon, but not efficiently. As a result, they are atrisk of developing low blood sugar (hypoglycemia) in response to excessinsulin.
The artificial pancreas described in the new study comprises a continuousblood sugar monitor and two pumps that communicate with each other via acomputer.
“We measure blood glucose on a laptop and have pumps to deliver insulin andglucagon, but there is continuous glucose monitoring, which will send wirelesssignals to the laptop that wirelessly controls the pumps that give insulin andglucagon,” says study researcher Steven J. Russell MD, PhD, an endocrinologistat Massachusetts General Hospital Diabetes Center in Boston. “It adds thecapability to give glucagon, and that hasn’t been available before and ispretty important.”
“It is well known that people with type I diabetes don’t make insulin, butthey also have a deficiency in making glucagon,” Russell tells WebMD.
If researchers get this right, “the benefits will be that people spend a lotless time thinking about and worrying about their diabetes and parents willworry less about their children with diabetes when they are away,” he says. “Itwill improve blood glucose control and reduce risk of developing complicationsof diabetes.”
Uncontrolled blood sugar levels wreak havoc on the body, causing suchcomplications as eye, nerve, and kidney damage among people with diabetes.
The new study looked at the two-hormone artificial pancreas system in 11adults with type 1 diabetes. Researchers monitored participants’ blood sugarlevels for 26 hours. They found that there was a great variation in insulinlevels. As a result, some participants developed low blood sugar. They thentweaked an algorithm to provide a slower insulin absorption and preventhypoglycemia. It worked.
“The results are very encouraging and suggest that an artificial pancreasusing insulin and glucagon in small doses works very well in a broad range ofpeople over 18 with significant variability in insulin absorption rates,” saysstudy co-researcher Edward R. Damiano, PhD, an associate professor ofbiomedical engineering at Boston University.”The new system may provide muchbetter glucose control and very little hypoglycemia risk.”
Future of the Artificial Pancreas
Careful not to call the artificial pancreas “the holy grail” as it has beencalled by some, Damiano tells WebMD that “the artificial pancreas is a stop-gapmeasure to get us through until we find a to a cure for type 1 diabetesor a way to prevent it.”
The researchers plan on testing the artificial pancreas on people aged12 and older for more than 48 hours to see if the results hold up. There willbe more testing after that, but if the results pan out, an artificial pancreascould be available within five years. An insulin-only artificial pancreas maywell come to market first.
Today, people with type 1 diabetes have a glucagon emergency kit which canbe used to reverse severe hypoglycemia. “The new system uses very small dosesthat are not much more than 1% of a rescue dose,” Damiano says. “The levels ofglucagon that are delivered are really small and close to normal range forpeople without diabetes.”
“This is super exciting and super important, but will take more time,” saysAaron Kowalski, PhD, assistant vice president for glucose control research atthe Juvenile Diabetes Research Foundation based in New York City, which fundedpart of the new research.
“The key here is the glucagon,” he says. As it stands, people with diabetesonly use insulin and turn to glucagon in an emergency. “It’s akin to driving acar with no brakes. The insulin acts as an accelerator, but there is no brakeif there is excess insulin. The new system has an accelerator and a brake.”