Real-World Glycemic Improvements with Hybrid Closed Loop Pumps in Youth with Type 1 Diabetes

Objective. The use of hybrid closed-loop insulin delivery systems, specifically the t:slim X2 insulin pump with Control IQ (CIQ), has demonstrated improvement in glycemic control in clinical trials and real-world settings. We sought to describe changes in glycemic control with use of CIQ in minority and nonminority youth. Research Design and Methods. This was a retrospective study of youth with type 1 diabetes (T1D) using CIQ over a 12-month period. Medical record data, pump data, and hemoglobin A1c (HbA1c) were collected from the visit prior to starting CIQ and at each clinic visit up to 12 months after starting CIQ. Continuous glucose monitor (CGM) data and HbA1c trajectory over time were compared to baseline and between minority and nonminority youth. Results. The study included 136 patients of whom 21 were minority youth (non-Hispanic Black and Hispanic), 50% were male, with median age of 13.3y, and median diabetes duration of 4.9y. After starting CIQ, baseline median HbA1c for the nonminority group decreased from 7.8% to 7.1% ( $p<0.001$ ), baseline median HbA1c for minority youth decreased from 9.8% to 7.8% ( $p=0.03$ ), and the percentage of patients meeting target HbA1c <7% increased from 26% to 45%. Both nonminority and minority youth had a significant increase in time in range and decrease of average CGM glucose ( $p<0.05$ ). Conclusions. HbA1c levels decreased in both minority and nonminority youth within 12 months of starting CIQ, and more patients reached the HbA1c target of less than 7%. Disparities in HbA1c between minority and nonminority youth remained and additional studies are warranted to improve this.