Beyond TIR: the impact of technology on glucose variability in a cohort of preschool children with T1D

In preschool children, high glucose levels and glucose fluctuations have been associated with detrimental effects on the developing brain. Although many studies show how Advanced Hybrid Closed Loop (AHCL) systems enhance common metrics, the evidence regarding their effect on glucose variability in this age group remains limited. To compare the effectiveness of Multiple Daily Injection (MDI) plus Continuous Glucose Monitoring (CGM) versus Sensor Augmented Pump (SAP) and AHCL in preschool children with T1D, focusing on glucose variability. A retrospective, one-year, observational, real-world study was performed involving 54 children with Type 1 Diabetes (T1D) < 6 years of age. CGM data were downloaded and entered into GlyCalculator3 software at three-month intervals (t3, t6, t9, t12). Patients were categorized into three groups according to the insulin delivery system used: MDI + CGM ( n = 31), SAP ( n = 12) and AHCL ( n = 11). AHCL showed significantly greater TIR compared to MDI at all timepoints ( p < 0.05). Similarly, TAR > 180 mg/dL ( p < 0.05 at t6, t9, t12) and TAR > 250 mg/dL ( p < 0.05 at t3, t6, t9, t12) were significantly reduced in the AHCL group versus MDI + CGM group. Both mean and median sensor glucose (SG) levels showed significant improvement in pump users. Although HbA1c did not reach statistical significance, the Glucose Management Indicator (GMI) was significantly lower in the AHCL group from t6 onwards. The high blood glucose index (HBGI) significantly improved in AHCL group showing statistical significance from t6 and persisting throughout the observation period ( p < 0.05 at t6, t9, t12). The multivariable linear regression analysis indicated that AHCL and SAP were associated with lower GMI, HBGI and Mean Amplitude of Glucose Excursion (MAGE) than MDI + CGM. Both AHCL and SAP systems significantly reduce glucose variability in preschool children with T1D and should be preferred over MDI + CGM in this age group. AHCL outperformed across standard glycemic metrics, supporting its use as the optimal therapeutic strategy.