An artificial pancreas system that uses a smart phone app coupled with a glucose sensor and an insulin pump has shown promise in a preliminary trial in people with type 1 diabetes, researchers report.
Currently, patients with type 1 diabetes must check their blood sugar levels throughout the day. Many use insulin pumps that deliver a set amount of the hormone to the body through a catheter 24 hours a day. But meal consumption, exercise and other factors can boost blood sugar levels or cause them to drop, and then the patient needs to adjust the amount of insulin being pumped into the body.
The new app, which was tested under Food and Drug Administration protocols on six adults with type 1 diabetes, works with two different brands of pumps and two types of glucose sensors, researchers reported in Diabetes, Technology and Therapeutics.
"These are baby steps toward enabling the technology to be part of wearable devices so people can manage their diabetes without needing to pull out an insulin pump or sensor in public," said senior author Eyal Dassau of the Harvard John A Paulson School of Engineering and Applied Sciences in Cambridge, Massachusetts. "You can just look at a screen and no one will know you have diabetes."
Today's pumps can keep a steady flow of insulin that can be modulated by the user with a turn of the button if glucose levels fluctuate. But these are not "smart" devices, Dassau said. "You can program them to account for meals," he said. "But what's missing is the brain that can read glucose every five minutes from a sensor."
And while hackers have developed similar workarounds, those have not been tested in clinical trials, Dassau said. "All our studies are regulated by the FDA," he added.
During the 48-hour study, patients took long walks without giving an alert to the app and consumed significant amounts of carbohydrates. In fact, every meal was eaten at a restaurant and the dinner meal included ice cream.
Despite those challenges to the new system, the researchers saw a trend toward improved time in the target glucose range of 70 to 180 mg/dL and a significant reduction of time when blood sugar was dangerously low. None of the six patients experienced high blood sugar, even with the high carb meals, and the incidence of low blood sugar was reduced.
In type 1 diabetes, the pancreas produces little or no insulin, the hormone that works "like a traffic cop telling sugar where to go and when," said Dr. Jason Ng, an endocrinologist at the University of Medicine at the University of Pittsburgh. "So, what happens when you've lost the ability to modulate insulin is you lose the ability to direct sugar where to go or when to stay in the blood. And because of that, you have to be given insulin."
While there have been great strides in the development of pumps and sensors, putting them together with some sort of algorithm has been "the holy grail," said Ng, who was not involved in the new study.
Hackers have tried for years to get glucose sensors and pumps to talk to one another.
"It's been kind of a wild, wild west out there," Ng said.
The problem with the current study is that it was so small. "You can't make too many conclusions based on that many patients," Ng said.
Larger studies are needed to confirm the safety and effectiveness of the new artificial pancreas app. But a big advantage would be that it can be used on the person's own cell phone, said Dr. Samuel Sultan, abdominal transplant surgeon at NewYork-Presbyterian/Weill Cornell Medical Center.
"As progress with the artificial pancreas continues, ultimately patients with diabetes will have healthier lives and better quality of life," Sultan said. "And from my perspective as a transplant surgeon, fewer patients may undergo a pancreas transplant, which requires major surgery, and immunosuppressive medications to prevent rejection."