An experimental “artificial pancreas” that pairs with a smartphone to monitor blood sugar and automatically deliver insulin may work better for teens with type 1 diabetes than using separate products already on the market, a small study suggests.

Researchers tested the artificial pancreas, formally known as a closed-loop insulin delivery system, in a group of 12 young diabetics around the clock for a week and then compared how well it worked relative to another week when they used separate devices to monitor glucose and pump insulin.

With the artificial pancreas, the teens had significantly lower average blood sugar levels of 8.7 mmol/liter (about 157 mg/deciliter), compared to 10.1 mmol/L (182 mg/dl) with the separate devices.

In the U.S., diabetes is diagnosed when fasting blood sugar is 126 mg/dl or higher. For this experiment, the safe target range was 3.9 mmol/L (70 mg/dl) to 10 mmol/L (180 mg/dl).

The teens’ glucose was within that safe target range 72 percent of the time when using the artificial pancreas versus 53 percent of the time with the separate devices. Time spent with dangerously low blood sugar was minimal and about equal with both systems, the researchers found.

“The present study adds knowledge about performance in teenagers who are particularly vulnerable to poor glucose control,” said lead author Dr. Roman Hovorka, director of research at the University of Cambridge Metabolic Research Laboratories in the U.K.

“Home testing in very young children and elderly will follow,” Hovorka added by email. “The application of the artificial pancreas is not limited by age but by the ability to use the insulin pump and continuous glucose monitor.”

In type 1 diabetes, a chronic condition typically diagnosed in children and young adults, the pancreas produces little or no insulin, a hormone needed to allow blood sugar, or glucose, to enter cells and produce energy. Poorly controlled, diabetes can lead to cardiovascular disease, kidney complications and death.

People with type 1 diabetes typically have to test their own blood sugar levels throughout the day and inject insulin to manage it. Nights are often a problem because dangerous blood sugar changes can happen while the person is sleeping, and automatic blood sugar monitoring and delivery of insulin is one solution.

To see if teens could safely and effectively use the artificial pancreas system without supervision, Hovorka and colleagues tried the product in a group of youth who were 15 years old on average.

Beyond the better disease control found with the artificial pancreas, the experiment also turned up no serious side effects with this approach. Importantly, the occurrence of hypoglycemia, or dangerously low blood sugar, was rarer than seen in previous experiments, the authors note in the journal Diabetes Care.

The experiment is small and brief, and more studies involving more people over much longer periods of time will be needed before an artificial pancreas can be approved for widespread use, the authors caution.

Still, this is the first trial investigating round-the-clock home use of the artificial pancreas in teens with type 1 diabetes, and the findings suggest that patients this age may be capable of using the option, the authors note.

In the U.S., an artificial pancreas might win regulatory approval as early as next year, Hovorka said.

“Commercial devices derived from this work could potentially affect 30 to 50 percent of the type 1 diabetes population in wealthy countries such as Western Europe, the U.S. and Japan,” said Marc Breton, an engineer at the Center for Diabetes Technology Research at the University of Virginia in Charlottesville.

The timeline for availability might be closer to two or three years, Breton, who wasn’t involved in the study, said by email.

Currently, the best available option for seamless control of type 1 diabetes is an insulin pump that stops delivering the hormone into the body whenever a separate continuous glucose monitor gets a blood sugar reading below a predetermined threshold, Breton noted.

“The artificial pancreas will vastly improve on this as it reduces insulin prior to a hypoglycemia developing, and maintains (blood sugar) in the desired range,” Breton added. “It also allows for potentially very variable insulin deliveries from day to day, which seems necessary for well controlled blood glucose.”

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