Progress toward automated insulin delivery technology has been made since the artificial pancreas, or closed-loop insulin delivery system, was developed for patients with type 1 diabetes.1 The United States Food and Drug Administration (FDA) approved the first closed-loop system from Medtronic in 2016, the MiniMed 670G.2

Years before this device was approved, many patients had already been implementing the technology into their diabetes care by using the Open Artificial Pancreas System (OpenAPS). OpenAPS is a widely accessible system based on open-source code that allows patients to program their own closed-loop system between separate FDA-approved devices, a process called “looping.”3,4 Patients started using OpenAPS after hackers exploited a security flaw in an older model of a Medtronic pump to run an algorithm that predicts future blood sugar and commands the insulin pump to dispense accordingly.4

The first system that inspired OpenAPS was completed in 2014, built out of a need to reduce type 1 diabetes burden and refusal to wait for the commercial systems that were years away from approval.3 Anxious to find a solution that allows more control and flexibility of glucose monitoring and delivery, a growing number of patients are becoming interested in improving technology in diabetes self-directed care.5

Studies analyzing the safety and efficacy of commercial closed-loop delivery systems have demonstrated significant benefits from outpatient use of automated insulin delivery systems, including increased percentage of time within the normoglycemic range, reduced hypoglycemia and hyperglycemia, and fewer adverse events.6-9

Approved closed-loop systems, however, are certainly not without flaws. At the Endocrine Society’s 2019 annual meeting, researchers presented findings from a study that indicated a large proportion of patients had stopped using their MiniMed 670G hybrid closed-loop insulin pump within a few months.10 Patients cited difficulty with staying in automode, technical difficulties with use of the system, calibration requirements, and skin irritation and adhesion problems.10

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“Setting realistic expectations, users will need to be trained and understand the new opportunities and challenges closed-loop systems present,” cautioned Roman Hovorka, PhD, FMedSci, Professor of Metabolic Technology at the University of Cambridge Metabolic Research Laboratories. “Data flows and utilization will be another key aspect of maximizing benefits of closed-loop technologies.”

Dr Hovorka stressed the importance of following regulatory approvals of closed loop system(s) for use across all age groups that include very young children, and the necessity for appropriate training of healthcare professionals.

“This is not trivial and it requires time and resources by manufacturers and healthcare providers,” Dr Hovorka said.

In a statement issued on May 17, 2019, the FDA warned patients with diabetes and their healthcare providers against the use of continuous glucose monitors (CGMs), insulin pumps, or automated insulin dosing system devices not authorized for sale in the United States.11 Use of unauthorized devices, the FDA stated, could lead to inaccurate glucose level readings and subsequent insulin dosing that could lead to injury or death.

The FDA urged patients and providers to promptly report adverse events to help identify and better understand the risks associated with using CGMs, automated insulin dosing systems, and insulin pumps.11

As for the future of looping, many patients prefer personalized systems that allow for use of their preferred CGM and more flexibility in setting blood glucose targets. Tidepool, a 501(c)3 nonprofit organization, is bringing together a hybrid closed-loop system within an application for use on iPhones and Apple Watches, called Loop, which will work with commercially available insulin pumps and CGM devices.12

They have also partnered with Insulet, which manufactures the Omnipod® Insulin Management System, to create a more sophisticated version of the Loop-Omnipod system used by do-it-yourself loopers.13

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1. Thabit H, Hovorka R. Coming of age: the artificial pancreas for type 1 diabetes. Diabetologia 2016;59(9):1795-1805.

2. US Food and Drug Administration. The Artificial Pancreas Device System. Updated August 30, 2018. Accessed May 22, 2019.

3. OpenAPS. Frequently Asked Questions. Accessed May 21, 2019.

4. Ragan SM. Medicine Ignored This Insulin Problem. Hackers Solved It. Neo.Life. August 9, 2018. Accessed May 21, 2019.

5. Lewis D, Leibrand S. Real-world use of open source artificial pancreas systems. J Diabetes Sci Technol. 2016;10(6):1411.

6. Bally L, Thabit H, Kojzar H, et al. Day-and-night glycaemic control with closed-loop insulin delivery versus conventional insulin pump therapy in free-living adults with well controlled type 1 diabetes: an open-label, randomised, crossover study. Lancet Diabetes Endocrinol. 2017;5(4):261-270.

7. Bergenstal RM, Garg S, Weinzimer SA, et al. Safety of a hybrid closed-loop insulin delivery system in patients with type 1 diabetes. JAMA. 2016;316(13):1407-1408.

8. Garg SK, Weinzimer SA, Tamborlane WV, et al. Glucose outcomes with the in-home use of a hybrid closed-loop insulin delivery system in adolescents and adults with type 1 diabetes. Diabetes Technol Ther. 2017;19(3):155-163.

9. Tauchmann M, Thabit H, Bally L, et al. Closed-loop insulin delivery in suboptimally controlled type 1 diabetes: a multicentre, 12-week randomised trial. Lancet. 2018;392(10155):1321-1329.

10. Goodwin D, Waldman G, Lyons J, Oladunjoye A, Steil G. Challenges in implementing hybrid closed loop insulin pump therapy (Medtronic 670G) in a ‘real world’ clinical setting. J Endocrinol Soc. 2019;3(Supplement_1):OR14-5.

11. US Food and Drug Administration. FDA Warns People With Diabetes and Health Care Providers Against the Use of Devices for Diabetes Management Not Authorized for Sale in the United States: FDA Safety Communication. Published May 17, 2019. Accessed May 22, 2019.

12. Tidepool. Tidepool Loop. Accessed May 21, 2019.

13. Insulet Corporation. A platform for innovation. Accessed May 21, 2019.