Changes in ambulatory glucose profile in people with type 1 diabetes using an automated insulin delivery system - two year follow-up retrospective analysis of real-world data

The number of available automated insulin delivery (AID) systems is increasing in Austria and people with diabetes (PwD) replace sensor-augmented pump (SAP) therapy more and more frequently. The present study is the two years follow-up of our prior monocentric, retrospective analysis conducted between 2019 and 2021, comparing SAP and open-source AID systems in people with type 1 diabetes. This second-year analysis included 25 PwD and investigated glycemic changes based on ambulatory glucose profiles (AGP). In comparison to the first year, a worsening of mean glucose (125.4 to 135.2 mg/dl, P = 0.038), time in range ((TIR), 84.2 to 77.0%, P = 0.012), time above range ((TAR), 11.6% to 18.5%, P = 0.017) and glycemia risk index ((GRI), 24.8 to 35.0%, P = 0.026) was observed. The reduction of mean glucose and glucose variability with AID in the first year was due to a significant decrease in time in hyperglycemia with resulting higher TIR and lower GRI. In this second-year follow up, TIR and GRI showed a significant deterioration, a familiar phenomenon in diabetology. However, open-source AID systems showed continuous safety, as there was no increase in time below range (TBR) even after two years. Despite the slight deterioration in the glycemic parameters, open-source AID systems were able to demonstrate sufficient glycemic control according to international consensus guidelines while offering the characteristic benefits of a reduced burden of diabetes management. A descriptive comparison of different AID algorithms indicated an improved glycemic control with more advanced features such as basal rate modification, auto bolus function and autotuning.