New Strides Toward Artificial Pancreas
Studies Pave the Way for Development of Closed-Loop Insulin System to Treat Diabetes
Treatment With an Artificial Pancreas continued...
In contrast, only 54% of them reached recommended blood sugar levels when they switched to a more conventional insulin pump.
With the new system, blood sugar is monitored even while a person is asleep, Weinzimer says. That's important because dangerous dips in blood sugar at night, while the patient is sleeping, are one of the greatest risks faced by children and adults with type 1 diabetes, he tells WebMD. The episodes can cause seizures and even sudden death.
After a sedentary day spent resting in the hospital, participants experienced two episodes of abnormally low blood sugar at night when they used the closed-loop device, compared with eight when they pumped their own insulin. After a day during which they exercised, there was one incident of hypoglycemia at night on the artificial pancreas, compared with 14 with the insulin pump.
Participants were hooked to a Medtronic Inc. glucose monitor, which sent a signal to a laptop computer. A program calculated how much insulin was needed and a signal was sent to the patient's insulin pump.
The computer programs can be run on a smaller device than a laptop, and the researchers plan to combine the sensor and pumping components into one unit, according to Weinzimer.
Artificial Pancreas vs. Conventional Therapy
A British team found that a closed-loop delivery system helped to improve daytime and overnight control of blood sugar levels and reduce the risk of hypoglycemia.
Twelve teenagers with type 1 diabetes were assigned to either the artificial pancreas system or conventional insulin pump therapy. Over a 36-hour period, participants engaged in normal daily activities such as playing computer games and walks, ate regular meals and snacks, and worked out on a stationary bike for a total of 60 minutes.
Blood sugar levels were in the target range 82% of the time among patients using the closed-loop system and 55% of the time among the conventional pump group. There were 11 episodes of low blood sugar in the conventional loop group vs. nine in the closed-loop group.
"The closed-loop system may improve glucose control significantly compared to conventional [pumps]. Further adjustments are needed to optimize insulin delivery to minimize risk for hypoglycemia after exercise and around meals," says researcher Roman Hovorka, PhD, of the University of Cambridge.
In another study, researchers from the Mayo Clinic found that even a little physical activity after meals has a profound impact on blood sugar levels in people with type 1 diabetes.
The researchers plan to incorporate their data into the sophisticated software program that drives their closed-loop system, says endocrinologist Yogish Kudva, MBBS.
Clinical trials of Mayo's artificial pancreas are set to begin in November in a handful of hospital volunteers, he says. More than a dozen other trials of other closed-loops systems are either under way or in the planning stage.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.