Study Shows Impressive Time in Range Increase for People With Type 2 Diabetes
By Eugenia Yun
New study results showed that using an artificial pancreas, or fully closed-loop automated insulin delivery system, improved time spent in a healthy glucose range by eight hours per day for people with type 2 diabetes.
An “artificial pancreas,” a fully automated closed-loop insulin delivery device developed at the University of Cambridge in the UK, is safe and effective for the management of type 2 diabetes in adults, adding an additional eight hours per day to the time in target blood glucose range, according to a new study published in Nature Medicine.
Time in range was doubled using the artificial pancreas compared with standard therapy (66% time in range vs 32%). Hyperglycemia (high blood glucose) occurred half as often (33% vs 67%), and average glucose levels and A1C were significantly lower with the artificial pancreas compared with standard therapy.
“Many people with type 2 diabetes struggle to manage their blood sugar levels using currently available treatments, such as insulin injections. The [Cambridge] artificial pancreas can provide a safe and effective approach to help them, and the technology is simple to use and can be implemented safely at home,” said Dr. Charlotte Boughton, who co-led the study, in a University of Cambridge news release.
Type 2 diabetes is usually treated with lifestyle interventions (such as diet and exercise) that best work for each individual, and medications to manage blood glucose levels. Unfortunately, even with the availability of modern therapies, glucose management remains difficult.
Automated insulin delivery devices have been used previously in type 1 diabetes, but where this differs is that it is a “fully closed-loop” system, meaning users don’t have to input information to the device about what they are about to eat. The system functions completely automatically; there is no carb counting or bolusing required by the user.
This system was already shown to be effective for glucose control in a previous study of people who had type 2 diabetes and kidney disease requiring dialysis, but the benefits of this approach in a wider population with type 2 diabetes were unclear. This study aimed to find out.
Researchers from the Wellcome-MRC Institute of Metabolic Science at the University of Cambridge enrolled 28 adults with type 2 diabetes on insulin therapy to compare the safety and effectiveness of a fully automated artificial pancreas with standard insulin therapy. The device consisted of the CamAPS HX app on an Android smartphone, the Dexcom G6 continuous glucose monitor to receive data, and an insulin pump. The artificial pancreas (aka closed loop insulin pump) system uses a Dexcom glucose sensor, insulin pump, algorithm to tell the pump how much insulin to administer and the Android smartphone app.
The study was conducted at a single center in the UK. Half of the 28 participants were randomly assigned to use the artificial pancreas and the other half to receive standard insulin therapy. After 8 weeks, all participants underwent a two- to four-week “washout period” where they used standard insulin therapy and fingerstick glucose monitoring. The participants were then switched to receive the opposite mode of therapy for another 8 weeks.
The average age of the participants was 59 and average BMI was 35 kg/m2. The participants had been living with diabetes for an average of 17.5 years, had been on insulin for an average of 8.5 years, and had an average starting A1C of 9.0%. Very few participants had experience using a CGM, but many were taking other medications in addition to insulin—mostly metformin, GLP-1 receptor agonists, and SGLT-2 inhibitors.
Participants using the artificial pancreas experienced a significant improvement in time in range; time in range doubled from 32% with standard therapy to 66% with the artificial pancreas, which is equal to 8 hours extra per day in range. This improved control of glucose levels was maintained through the day and night, and was observed soon after starting on the closed-loop system—within the first 2 weeks. Glucose control continued to improve every two weeks thereafter.
“This likely represents the algorithm becoming more tailored to the individual,” said Dr. Aideen Daly during her presentation of the study results at an online forum for the Advanced Technologies & Treatments for Diabetes on Jan 11.
A1C was also significantly lower after using the artificial pancreas, though it remained above target. “We would propose that a longer time duration and using the system for more than 8 weeks with further optimization of the algorithm would improve A1C further,” said Daly.
Interestingly, the total daily insulin used was greater while using the artificial pancreas, which the investigators stated may be an indication of the undertreatment of participants in the standard treatment group. “Because the participants [using the artificial pancreas] had superior glucose control without hypoglycemia, we feel that this signifies that we can intensify insulin therapy [in people with type 2 diabetes] without causing hypoglycemia,” Daly said.
None of the study participants experienced severe hypoglycemia, and there was no significant difference in the time spent in hypoglycemia between the two groups. Only one serious adverse event was study-related: the development of an abscess at the cannula insertion site. There were seven non-study-related adverse events, such as skin reactions and COVID.
In terms of acceptability, all the participants were happy to have their blood glucose levels automatically controlled, and all participants indicated that they would recommend the system to others.
In a survey sent at the completion of the trial, the respondents stated that they liked not having to do finger pricks, not having to inject insulin, and the feeling of having tighter control of their blood glucose levels. They stated that the artificial pancreas gave them a sense of freedom. “A complete life changer,” was one comment. What they didn’t like about the system was related to practical annoyances, such as having to refill the pump every 3-4 days, being attached to the device, and technical issues like Bluetooth connectivity problems.
This study, however, had several limitations. It was a small study conducted at only one center. It was also lacking in ethnic diversity, with only one non-white participant. The authors noted that larger trials conducted for a longer period of time, with a more diverse population, will provide information on whether the artificial pancreas will be effective for the general population with type 2 diabetes.
“These are the most impressive results I’ve seen with a fully closed-loop system,” said Dr. Roy Beck of the Jaeb Center for Health Research during the Q&A period of the oral presentation session. He also authored the accompanying commentary on this study. “Even though the sample size was small, I don’t think there’s any reason to think we won’t see [similar results] in the broader population.”