Outpatient Closed-Loop Control with Unannounced Moderate Exercise in Adolescents Using Zone Model Predictive Control.

Area of Science:

• Endocrinology
• Biomedical Engineering
• Pediatrics

Background:

• Artificial pancreas (AP) systems offer potential for improved glycemic management in adolescents.
• Adolescents with type 1 diabetes (T1D) face unique challenges in glucose control due to lifestyle factors like exercise and varied meal intake.
• Evaluating novel AP algorithms in real-world, outpatient settings is crucial for clinical adoption.

Purpose of the Study:

• To evaluate the Zone Model Predictive Control and Health Monitoring System (ZMPC+HMS) artificial pancreas algorithms in adolescents with T1D.
• To assess the efficacy and safety of the ZMPC+HMS AP in a supervised outpatient setting with frequent, unannounced exercise and unrestricted meals.
• To compare glycemic control achieved by the ZMPC+HMS AP with sensor-augmented pump (SAP) therapy.

Main Methods:

• Ten adolescents (aged 11.9-17.7 years) participated in a 72-hour closed-loop control (CLC) study using the ZMPC+HMS AP on the Diabetes Assistant platform.
• Participants engaged in twice-daily exercise sessions (e.g., soccer, tennis, cycling) without prior announcement to the system.
• Meal carbohydrate content was estimated and entered by participants, while exercise was not communicated to the AP system.

Main Results:

• The ZMPC+HMS AP achieved 71% time in the target glucose range (70-180 mg/dL), significantly higher than the 57% achieved with SAP therapy (P=0.012).
• No severe hypoglycemia occurred during CLC, with 0% time below 70 mg/dL compared to 1.1% during SAP.
• Despite large meals and unannounced exercise, only 8.0% of time was spent with glucose above 250 mg/dL during CLC, compared to 16% with SAP.

Conclusions:

• The ZMPC+HMS artificial pancreas algorithms are feasible for use in an adolescent outpatient environment.
• The ZMPC+HMS AP significantly improved time in the target glycemic range compared to SAP therapy.
• The system demonstrated safety and effectiveness in managing glucose levels during challenging conditions, including unannounced exercise and large meals.