Day and Night Closed-Loop Control Using the Integrated Medtronic Hybrid Closed-Loop System in Type 1 Diabetes at...

Area of Science:

• Endocrinology
• Biomedical Engineering
• Diabetes Technology

Background:

• Type 1 diabetes management requires continuous glucose monitoring and insulin delivery.
• Hybrid closed-loop (HCL) systems aim to automate insulin delivery for improved glycemic control.
• Evaluating novel HCL systems in real-world settings like diabetes camp is crucial.

Purpose of the Study:

• To assess the feasibility and efficacy of a fully integrated HCL system for type 1 diabetes.
• To evaluate closed-loop control during both day and night in inpatient and camp settings.
• To compare the HCL system against a threshold suspend system (Medtronic MiniMed 530G).

Main Methods:

• A fully integrated HCL system with a 4S glucose sensor and PID algorithm was studied.
• Eight subjects participated in a 48-hour inpatient feasibility study.
• Twenty-one subjects were randomized for 6 days at diabetes camp, comparing HCL to the control group.

Main Results:

• No significant difference in sensor glucose time in range (70-180 mg/dL) between HCL and control groups (73.1% vs. 69.9%).
• Meter glucose values within the target range were also similar between groups (73.6% vs. 63.2%).
• The 4S sensor demonstrated acceptable accuracy (mean absolute relative difference of 10.8-12.6%).

Conclusions:

• The investigational PID algorithm in the fully integrated HCL system did not outperform sensor-augmented pump therapy alone.
• The system exhibited robust connectivity and enhanced glucose sensor performance.
• Further research may be needed to optimize algorithms for improved glycemic control with HCL systems.