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Directors' Report

September 2022

Hybrid Closed-Loop Insulin Pumps Might Protect Childhood Brain Development from the Adverse Effects of Type 1 Diabetes

Over the past decade, evidence has emerged indicating that high blood sugars in type 1 diabetes cause adverse brain changes in children. The adverse changes include abnormal brain structural alterations and reduced functioning on some cognitive tests. Over the past few years, hybrid closed-loop insulin pumps have become commercially available. These devices combine a continuous glucose monitor (CGM) with an insulin pump that is controlled by an algorithm that uses the CGM data to inform insulin delivery. The hybrid closed-loop insulin pumps aim to keep blood sugar in the low 100s (mg/dL). These systems can often improve average blood sugars and reduce the severity and frequency of low and high blood sugars. It is thus natural to ask whether the improved blood sugar control offered by a hybrid closed-loop insulin pumps might reduce the adverse brain effects of type 1 diabetes in children. FOEDRC faculty Dr. Mike Tansey and Dr. Eva Tsalikian were among a small group of diabetes physicians across the United States who designed such a study to answer this very question. The initial results from the study were just published in the prestigious journal Nature Communications. Their randomized clinical study involved 42 adolescents with type 1 diabetes who were randomized to a hybrid closed-loop insulin pump versus conventional therapy. They were studied 6 months later, undergoing a brain MRI and cognitive testing. Although this study was considered a pilot trial, the results showed significantly less adverse impacts in those randomized to the hybrid closed-loop insulin pumps. The hybrid closed-loop insulin pump group performed better on a cognitive test of perceptual reasoning and had fewer abnormal structural brain changes. These results add to the growing evidence showing that excessive hyperglycemia is damaging to the developing brain during childhood. This study shows the important positive impact that hybrid closed-loop insulin pumps can make in improving blood sugar levels and long-term outcomes in children with diabetes.