Prospective multicenter evaluation of glycemic and patient-reported outcomes following transition to a next-generation continuous glucose monitoring system in users of advanced hybrid closed-loop technology

Aims: To assess the real-world impact of transitioning from the Dexcom G6 ® to G7 ® system in individuals with type 1 diabetes (T1D) using the Tandem t:slim X2™ with Control-IQ™. Primary outcomes included glycemic control changes, while secondary outcomes evaluated patient-reported outcomes (PROMs) and experiences (PREMs). Methods: A 3-month prospective, multicenter, observational study was conducted in individuals previously using Dexcom G6 and Control-IQ. Glycemic control was assessed via TIR 70–180 and HbA 1c . PREMs and PROMs were measured using validated questionnaires (Diabetes Quality of Life (DQoL), Type 1 Diabetes Life (ViDa1), Diabetes Distress Scale (DDS), and Diabetes Treatment Satisfaction Questionnaire). Statistical analyses were stratified by baseline TIR 70–180 (>70% vs <70%) and sex. Results: The study included 92 participants (mean age 38 ± 13 years), with a baseline TIR 70–180 of 76% ± 10%. The overall TIR 70−180 remained stable throughout the study. However, among participants with baseline TIR 70–180 <70%, a significant increase in TIR 70−180 was observed, rising from 61% ± 9% to 65% ± 7% ( p = 0.007). In consonance, HbA 1c levels showed a significant decline, from 7.3% ± 0.9% to 7.0% ± 0.6% ( p = 0.001). In addition, both glucose management indicator (GMI) and mean glucose levels significantly decreased over time, reflecting an overall improvement in glycemic control. These changes (GMI and glucose levels) were consistent across groups, with no significant differences based on baseline TIR 70-180 stratification. Quality of life and diabetes distress improved (DQoL, ViDa1, and DDS), especially in participants with lower baseline TIR 70-180 and in women. Some reported increased connectivity issues, but none led to treatment discontinuation. Conclusion: In Control-IQ users, the transition to G7 ® did not significantly impact glycemic control overall. However, a subgroup of patients with suboptimal baseline control (TIR 70–180 <70%) may benefit from this change, and enhanced quality of life and diabetes distress, especially in women.