Artificial pancreas yields good results in type 2 diabetes patients

A fully closed-loop insulin delivery system, also known as artificial pancreas, helps improve the management of type 2 diabetes (T2D) in adults, increasing the time spent in target glucose range by 8 hours per day without promoting hypoglycaemic events as compared with standard insulin therapy, as reported in a study.

“The results of this study build on evidence from a feasibility study evaluating fully closed-loop therapy in people with T2D and end-stage renal failure on dialysis. Here, we demonstrate that this technology can benefit the wider population with T2D requiring insulin and can be safely implemented in the home setting,” according to investigators from the Wellcome-MRC Institute of Metabolic Science at the University of Cambridge in the UK. [Nat Med 2021;27:1471-1476]

In a crossover trial, 8 weeks of use of artificial pancreas in an outpatient setting had participants spending 66.3 percent of their time in target glucose range. This proportion was twice as high as that while on standard therapy consisting of multiple daily insulin injections (control, 32.3 percent; mean difference, 35.3 percentage points, 95 percent confidence interval [CI], 28.0–42.6; p<0.001). [Nat Med 2023;doi:10.1038/s41591-022-02144-z]

Mean glucose dropped from 12.6 mmol l⁻¹ while on control therapy to 9.2 mmol l⁻¹ while using the artificial pancreas (p<0.001). Mean HbA1c was also lower during the artificial pancreas period (7.3 percent vs 8.7 percent; mean difference, −1.4 percent, 95 percent CI, −1.0 to −1.8; p<0.001).

Nevertheless, the closed-loop system did not increase the proportion of time spent in hypoglycaemia (>10.0 mmol l⁻¹: 33.2 percent vs 67.0 percent with control therapy; p<0.001). None of the patients experienced severe hypoglycaemia events during either treatment period. One treatment-related serious adverse event—an abscess at the site of the pump cannula that required hospitalization—occurred during the closed-loop therapy period.

“Many people with T2D struggle to manage their blood sugar levels using the currently available treatments, such as insulin injections. The 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, co-lead and corresponding investigator of the study.

“One of the barriers to widespread use of insulin therapy has been concern over the risk of severe 'hypos'—dangerously low blood sugar levels. But we found that no patients on our trial experienced these and patients spent very little time with blood sugar levels lower than the target levels,” added principal study investigator Dr Aideen Daly.

When asked for feedback regarding their experience with the artificial pancreas, all participants reported that they were happy to have their glucose levels controlled automatically by the system, with 89 percent indicating that they spent less time managing their diabetes overall.

The participants cited two major advantages of the closed-loop system: enhanced confidence in regulating blood glucose and doing away with injections or finger prick tests. Drawbacks included practical annoyances with wearing of devices as well as increased anxiety about the risk of hypoglycaemia, which, according to the investigators, may reflect increased awareness and monitoring of glucose levels.

“Increased exposure to diabetes technologies in people with T2D (insulin pumps and glucose sensors) may mitigate some of these negatives if the glycaemic benefits are perceived to be worthwhile. Future-generation closed-loop systems with improved connectivity, longer infusion set wear time, and larger insulin reservoirs may also resolve these issues,” they said.

The analysis included 26 patients (mean age 59 years, 27 percent female, 96 percent White, mean HbA1c 9.0 percent) with a mean T2D duration of 17.5 years. They had been on insulin therapy for a mean of 8.5 years, with the total daily insulin dose at 0.70 U kg⁻¹. All patients spent 8 weeks using artificial pancreas and another 8 weeks on control therapy, with a washout period in between.

Daly and Boughton, along with their team, intend to conduct a much larger multicentre study to build on their findings and have submitted the device for regulatory approval to make the closed-loop insulin delivery system commercially available for outpatients with T2D.