Closing the Loop with OpenAPS in People with Type 1 Diabetes—Experience from Italy

Background: Since 2017, people with type 1 diabetes (T1D) in Italy began to use spontaneously an Artificial Pancreas Systems (APS) with off-label use of existing insulin pumps, continuous glucose monitors (CGM), and open source software (known as OpenAPS). Aim of this study is to understand if closing the loop with OpenAPS is effective to improve the glucose control in T1D diabetes.

Methods: We studied 30 people (male/female = 19/11; age = 35.9 years ± 12.52 DS) with T1D who shared and self-reported their data and experiences from using this system. All the people included in the study used a CGM Dexcom G5 and insulin pump Dana Diabecare R; the implementation of OpenAPS realized a so called hybrid closed loop system. Main outcomes were A1c and % of time into hypoglycemia (glycemia < 70 mg%, %TIHypo), before and 3 months after closing the loop. Secondary outcomes were % of time into hyperglycemia (glycemia > 180 mg%, %TIHyper) and time into range (glycemia between 70 and 180 mg%, TIR).

Results: We observed a significant decrease of A1c (from 7.17% ± 0.49 DS to 6.61% ± 0.47 DS; p < 0.05) and of %TIHypo (from 8.55% ± 5.81 DS to 2.48% ± 1.16 DS). We also observed a decrease of TIHyper and an increase of TIR, but the differences were not statistically significant. All patients were satisfied of OpenAPS use and only one patient dropped out, on advice of his diabetologist. No any serious adverse event was recorded (diabetic ketoacidosis, serious hypoglycemia).

Discussion and Conclusions: Closing the loop with OpenAPS in people with T1D is effective in decreasing A1c and %TIHypo, without any serious adverse event. Of note, these results were obtained with people who showed a good baseline metabolic control (A1c of 7.17%). However, we need to study OpenAPS implementation on a larger sample of people with T1D and with a more prolonged follow-up.