New closed-loop system effective in BGL control

Friday, 18 October 2019

A multicentre clinical trial has found a new closed-loop system that uses advanced control algorithms to automatically monitor and regulate blood glucose levels was more effective than existing treatments at controlling blood glucose levels in people with type 1 diabetes.

The study from the Ichan School of Medicine, published in the New England Journal of Medicine, showed that the closed-loop system improved participants’ blood glucose control throughout the day and overnight. Overnight glucose control 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 closed-loop system also known as the artificial pancreas, is an “all-in-one” diabetes management system that tracks blood glucose levels using a continuous glucose monitor (CGM) and automatically delivers insulin when needed, using an insulin pump. The system replaces reliance on testing by finger prick or CGM with separate delivery of insulin by multiple daily injections or a pump.

The international multicentre study involves five separate artificial pancreas clinical protocols implemented by 10 research centres which included the Icahn School of Medicine at Mount Sinai. 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.

The study involved 168 participants aged 14 or older with type 1 diabetes. They were randomly assigned to use either the closed-loop 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 in which their blood glucose levels remained within the target range of 70 to 180 mg/dL (3.9 – 10 mmol) by an average of 2.6 hours per day, while the time in range in the SAP group remained unchanged over six months. Closed-loop 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.

The Control-IQ technology was derived from a system originally developed at the University of Virginia, Charlottesville. 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.

Dr Carol Levy, lead researcher on the trial said, “This system has some unique features to help patients achieve target glucose levels while reducing the risk of hypoglycemia. It has been an exciting study both for patients and the research team. By making management of type 1 diabetes easier and more precise by using closed-loop technology, the potential is tremendous to reduce the daily burden of this disease and improve long-term outcomes for our patients.”


Join our community of over 45,000 people living with diabetes