Another “Closed-Loop” Insulin Delivery System

Closed-loop systems for insulin delivery combine an insulin pump, a sensor for continuous glucose monitoring, and automated algorithmic adjustment of basal insulin infusion rates. In this U.S. trial, 168 patients with type 1 diabetes (71% adults; 29% adolescents [age range, 14–17]) were randomized to an investigational closed-loop system (Control-IQ) or to a control group (using an insulin pump augmented by continuous glucose monitoring). At baseline, mean glycosylated hemoglobin (HbA_1c) was 7.4%.

During 6 months of treatment, the percentage of time that blood glucose was in the target range (70–180 mg/dL) was significantly higher in the closed-loop group than in the control group (71% vs. 59%). This outcome reflected less time at both extre…