199-OR: Improved Glycemic Outcomes with Medtronic Minimed Advanced Hybrid Closed-Loop Delivery: Results from a Randomized Crossover Trial Comparing Automated Insulin Delivery with Predictive Low Glucose Suspend in People with Type 1 Diabetes

Abstract

Background: The Medtronic Minimed® Advanced Hybrid Closed-Loop system (AHCL) includes an individualised algorithm with optional set points, automated correction bolus, and improved SmartGuard™ Auto Mode stability. Methods: This dual-centre, randomized, open-label, two-sequence cross-over study in automated insulin delivery naïve participants (aged 7-80yrs), compared AHCL to Sensor Augmented Pump therapy with Predictive Low Glucose Management (SAP+PLGM). Each study phase was 4 weeks, preceded by a 2-4 week run-in, and separated by 2-week washout. Results: 59/60 people completed the study (mean age 23.3±14.4yrs). Overall time in target range (TIR) (70-180mg/dL) favoured AHCL over SAP+PLGM by 12.5±8.5% (p<0.001), with greater improvement overnight (15.7±12.0%, p<0.001) (Table 1). This was primarily due to reduction in hyperglycemia (-12.1±9.0% time spent >180mg/dL). Mean SG improved in AHCL by 10.0±7.4mg/dL (p<0.001). For each 1% lower baseline TIR, there was a 0.5% greater TIR improvement with AHCL (p<0.001). Auto Mode was active for 95.3±3.6% of the time. Conclusion: AHCL with automated correction bolus showed significant improvement in glucose control compared to PLGM, in a population with a younger mean age reflecting a challenging demographic. Disclosure O. Collyns: None. R. Meier: None. Z. Betts: None. D. Chan: None. C. Frampton: None. C.M. Frewen: None. B. Grosman: Employee; Self; Medtronic. N. Hewapathirana: Other Relationship; Self; Sanofi. S. Jones: None. N. Kurtz: Employee; Self; Medtronic. A. Roy: Employee; Self; Medtronic. J. Shin: Employee; Self; Medtronic. R. Vigersky: Employee; Self; Medtronic. B.J. Wheeler: Research Support; Self; Medtronic. M. de Bock: None.

Comparison Between Closed-Loop Insulin Delivery System (the Artificial Pancreas) and Sensor-Augmented Pump Therapy: A Randomized-Controlled Crossover Trial

“…Increasing basal rates by several folds over a short period of time can have the same effect as delivering a bolus (e.g., 6 U/h over 10 min delivers 1 U), and algorithms only modulating background basal rates have been shown to improve glucose control compared with sensor-augmented pump therapy [7][8][9] as much as algorithms delivering automatic boluses. 10,14 In our study, no difference was observed between outcomes of week 1 and week 2, suggesting that the benefits of automated insulin delivery are immediate. This is also in line with results from longer studies over 3 to 6 months from other groups, 7,10 where benefits were observed after only 2 weeks.…”

“…Several randomized trials tested dosing algorithms for automated insulin delivery systems, comparing its efficacy to sensor-augmented pump therapy, in outpatient unsupervised settings with no remote monitoring. [7][8][9][10][11][12]14 Here, we present a relatively short study over 12 days that assesses our dosing algorithm in outpatient unsupervised settings. The algorithm was a less aggressive version than our previous algorithm, [18][19][20] to emphasize safety in our first outpatient study.…”

“…Unlike other algorithms, 10,14 our algorithm does not administer automatic boluses outside mealtimes. Algorithms that deliver automatic boluses in addition to modulating background basal rates are not necessarily more aggressive than algorithms that only modulate background basal rates.…”

“…The University of Virginia's algorithm was also tested in several clinical trials, [10][11][12] and showed improvements in glucose control, although the benefits were lower when the algorithm was embedded in a phone as opposed to a pump. 11,12 The Medtronic first-generation dosing algorithm was tested in several nonrandomized trials, 13 but their second-generation algorithm was recently tested in a 4-week randomized trial, 14 and also showed improvements in glucose control.…”

Advanced hybrid closed-loop system: first successful clinical case after total pancreatectomy

“…(respectively, 190 mg/dl or 10.6 mmol/l and 68 mg/dl or 3.8 mmol/l). We chose to take advantage of advanced hybrid closed loop (AHCL) to improve mean glucose levels and minimize variability: in fact, in subjects with T1DM AHCL increased of 12.5% TIR, with greater improvement overnight [5]. AHCL allowed our patient to improve metabolic control and all the glycemic variability metrics.…”