In Adults with Type 1 Diabetes, is the Artificial Pancreas System More Effective than Open-loop Systems in Controlling Blood Glucose?

Abstract

Background: Despite advances in continuous glucose monitoring (CGM) and insulin pump therapy, many adults with type 1 diabetes (T1D) do not consistently achieve recommended glycemic targets. Automated insulin delivery (AID), often referred to as the artificial pancreas (AP), integrates CGM, an insulin pump, and a control algorithm to adjust insulin delivery in real time. Objective: To summarize contemporary evidence comparing AP/AID (closed-loop or hybrid closed-loop) with open-loop approaches (e.g., sensor-augmented pump therapy or user-directed insulin dosing) for glycemic control in adults with T1D. Methods: We synthesized evidence from recent randomized controlled trials (RCTs) and meta-analyses in adults with T1D, focusing on clinically meaningful CGM-derived metrics (time in range [TIR], time below range), HbA1c, and safety outcomes. Reporting principles align with PRISMA 2020 where applicable. Results: Across modern RCTs and meta-analyses, AP/AID consistently improves TIR and reduces hyperglycemia compared with open-loop strategies, without increasing hypoglycemia. Key trials in older adults show clinically relevant gains in TIR with closed-loop systems versus sensor-augmented pump therapy. Meta-analytic evidence supports improved TIR and modest HbA1c reductions with closed-loop compared with open-loop approaches. Conclusion: In adults with T1D, AP/AID systems are more effective than open-loop regimens in improving glycemic control, offering better TIR and comparable or improved hypoglycemia safety profiles.