Artificial pancreas system better controls blood glucose levels than current technology

The study showed that the system improved participants' blood glucose control throughout the day and overnight. The latter is a common but serious challenge for children and adults with type 1 diabetes, since blood glucose can drop to dangerously low levels when a person is asleep. The research is published in the New England Journal of Medicine.

The artificial pancreas, also known as closed-loop control, is an "all-in-one" diabetes management system that tracks blood glucose levels using a continuous glucose monitor (CGM) and automatically delivers the hormone insulin when needed using an insulin pump. The system replaces reliance on testing by fingerstick or CGM with separate delivery of insulin by multiple daily injections or a pump.

The International Diabetes Closed-Loop (iDCL) Study involves five separate artificial pancreas clinical protocols implemented by 10 research centers, including CU Anschutz. This six-month study was the third phase in the series of trials. It was conducted with participants living their usual day-to-day lives, so the researchers could best understand how the system works in typical daily routines.

"Testing the safety and effectiveness of new technologies in real-world settings is critical to prove the usability of these systems by people with diabetes to achieve a better daily control of their blood glucose levels," said Guillermo Arreaza-Rubín, M.D., director of NIDDK's Diabetes Technology Program and project scientist for the study.

This iDCL protocol enrolled 168 participants age 14 or older with type 1 diabetes. They were randomly assigned to use either the artificial pancreas system called Control-IQ or sensor-augmented pump (SAP) therapy with a CGM and insulin pump that did not automatically adjust insulin throughout the day. Participants had contact with study staff every two to four weeks to download and review device data. No remote monitoring of the systems was done, so that the study would reflect real-world use.

The researchers found that users of the artificial pancreas system significantly increased the amount of time with their blood glucose levels in the target range of 70 to 180 mg/dL by an average of 2.6 hours per day since beginning the trial, while the time in range in the SAP group remained unchanged over six months. Artificial pancreas users also showed improvements in time spent with high and low blood glucose , hemoglobin A1c, and other measurements related to diabetes control compared to the SAP group.

High adherence to device use in both groups and 100% participant retention were important strengths of the study. During the study, no severe hypoglycemia events occurred in either group. Diabetic ketoacidosis occurred in one participant in the artificial pancreas group due to a problem with equipment that delivers insulin from the pump.

The Control-IQ technology was derived from a system originally developed at the University of Virginia, Charlottesville, (UVA) by a team led by Boris Kovatchev, Ph.D., director of the UVA Center for Diabetes Technology with funding support from NIDDK. In this system, the insulin pump is programmed with advanced control algorithms based on a mathematical model that uses the person's glucose monitoring information to automatically adjust the insulin dose. Tandem Diabetes Care has submitted the results to the U.S. Food and Drug Administration for approval to market the Control-IQ system.

"This artificial pancreas system has several unique features that improve glucose control beyond what is achievable using traditional methods," said Kovatchev. "In particular, there is a special safety module dedicated to prevention of hypoglycemia, and there is gradually intensified control overnight to achieve near-normal blood sugar levels every morning."

Kovatchev was co-lead author of the study with colleagues Sue A. Brown, M.D., of UVA and Roy Beck, M.D., Ph.D., from the Jaeb Center for Health Research, Tampa, Florida, which was the coordinating center for the study.

"This study demonstrated that in participants with type 1 diabetes, use of the Control IQ system led to improved glucose control during both the day and night for a wide range of ages including adolescents to older adults," said co-author R. Paul Wadwa, MD, associate professor of pediatrics at the Barbara Davis Center for Childhood Diabetes at CU Anschutz. "We greatly appreciate the involvement of participants and hard work of study teams to complete this important study. We are hopeful that the system studied in this trial will potentially offer a valued treatment option to benefit people with type 1 diabetes."

The study was funded through NIDDK grant UC4DK108483. Tandem Diabetes Care provided the experimental closed-loop systems, supplies, and technical expertise with device issues. The University of Virginia Strategic Investment Fund Project #88 provided institutional and regulatory support.