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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

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posted on 12.02.2021, 18:28 by Olivia J Collyns, Renee A Meier, Zara L Betts, Denis SH Chan, Chris Frampton, Carla M Frewen, Niranjala M Hewapathirana, Shirley D Jones, Anirban Roy, Benyamin Grosman, Natalie Kurtz, John Shin, Robert A Vigersky, Benjamin J Wheeler, Martin I de Bock

To study the MiniMed™ Advanced Hybrid Closed-Loop system (AHCL) which includes an algorithm with individualised basal target set points, automated correction bolus function, and improved Auto Mode stability.
Research design and Methods:

This dual-centre, randomized, open-label, two-sequence cross-over study in automated insulin delivery naïve participants with type 1 diabetes (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.

59/60 people completed the study (mean age 23.3±14.4yrs). Time in target range (TIR) 3.9-10mmol/L (70-180 mg/dL) favoured AHCL over SAP+PLGM (
70.4±8.1 vs 57.9±11.7) by 12.5±8.5% (p<0.001), with greater improvement overnight (18.8±12.9%, p<0.001). All age groups (children (7 – 13 years), adolescents (14 – 21 years), and adults (>22 years) demonstrated improvement, with adolescents showing the largest improvement (14.4±8.4%). Mean sensor glucose (SG) at run in was 9.3±0.9 mmol/L (167±16.2mg/dL) and improved with AHCL (8.5±0.7mmol/L (153±12.6mg/dL) (p < 0.001)), but deteriorated during PLGM (9.5±1.1mmol/L (17±19.8mg/dL), (p<0.001)).. TIR was optimal when the algorithm set point was 5.6 mmol/L (100 mg/dL) compared to 6.7 mmol/L (120 mg/dL), 72.0±7.9% vs 64.6±6.9% respectively with no additional hypoglycemia. Auto Mode was active 96.4±4.0% of the time. The percentage of hypoglycemia at baseline (<3.9mmol/L (70mg/dl) and £ 3.0mmol/L(54mg/dl)) was 3.1±2.1% and 0.5±0.6% respectively. During AHCL percentage time <3.9mmol/L (70mg/dl) improved to 2.1±1.4% (p=0.034) (70mg/dl), and was statistically but not clinically reduced for £ 3.0mmol/L(54mg/dl) (0.5±0.5%, p = 0.025) There was one episode of mild diabetic ketoacidosis attributed to an infusion set failure in combination with an intercurrent illness, which occurred during the SAP+PLGM arm.


AHCL with automated correction bolus demonstrated significant improvement in glucose control compared to SAP+PLGM. A lower algorithm sensor glucose set point during AHCL resulted in greater TIR, with no increase in hypoglycemia.


The study was financially supported by Medtronic. B.J.W and M.I.d.B. are financially supported by Otago University.