P-312: Trends in glycaemic outcomes based on the timing of hybrid closed-loop systems (HCLS) initiation after the onset of type 1 diabetes (T1D) among paediatric patients: an observational real-world study
J Pelicand, M Laurent, C MorinAbstract
Introduction
HCLS improve glycaemic outcomes for children with type 1 diabetes (T1D), yet timely initiation following diagnosis remains suboptimal.
Objectives
We evaluated the impact of increase early HCLS initiation among newly diagnosed children and adolescents with T1D.
Methods
Our single-centre, longitudinal, real-world observational study included youth aged 1-17 years who initiated HCLS between December 2023 and August 2025 as a standard care. Clinical data and continuous glucose monitoring (CGM) metrics were collected at HCLS placement (T0), after 1 month (T1) only for the patients with HCLS from the onset, and after 12 months from HCLS initiation (T2). Outcomes included HbA1c (%) and glycaemic metrics (time in range [TIR] 70–180 mg/dL, time below range [TBR] < 70 mg/dL, coefficient of variation [CV]).
Results
166 youth were included (49.4% girls; mean age: 7.52 +- 4.15 years). Patient outcomes were analysed and compared according to the timing of HCLS initiation: (1) more than a year after diagnosis, (2) within the year of diagnosis, and (3) at the time of onset. Mean HbA1c decreased and CGM metrics have improved across all 3 groups from pre-HCLS initiation to the year following HCLS initiation. But only in the group with HCLS initiation at the DT1 onset, optimal metrics and A1c glycaemic targets are achieved throughout the entire year of follow-up with HCLS (Table).
Conclusions
HCLS initiation was associated with rapid improvement of HbA1c and CGM in children and adolescents with T1D but starting HCLS immediately upon DT1 onset appears to enable the achievement of all glycaemic targets throughout the first year.