Real-world experience with insulin glargine U300 in pediatric type 1 diabetes: glycemic control, insulin requirements, and patient-reported outcomes.

BACKGROUND: Achieving optimal glycemic control in children with type 1 diabetes(T1D) is challenging. Insulin glargine U300 offers a flatter pharmacodynamic profile and longer duration of action than glargine U100, but pediatric real-world data are limited. This study evaluated the effects of switching from U100 to U300 on glycemic control, body composition, pain, and quality of life. METHODS: This prospective, single-center observational study included children aged 6–20 years with T1D who switched from U100 to U300. Assessments were performed at baseline, week12, and week24. The primary endpoint was change in HbA1c; secondary endpoints included insulin dose(U/kg), hypoglycemia frequency, 3:00 a.m. glucose, lipid parameters, body composition, Numeric Rating Scale (NRS) for pain, and Pediatric Quality of Life Inventory (PedsQL) scores. Participants were stratified by baseline HbA1c (< 9% vs. ≥ 9%). RESULTS: Sixty-three participants (mean age 14.98 ± 3.53 years) were analyzed. Basal insulin dose increased significantly from 0.48 ± 0.12 U/kg/day on Gla-100 to 0.51 ± 0.14 and 0.51 ± 0.15 U/kg/day at weeks 12 and 24, respectively (p < 0.001). HbA1c levels demonstrated a small but statistically significant change during follow-up (p = 0.048). (8.20 (5.9–14.8) %→ 8.00 (6.0–12.2) %→ 8.25 (5.7–12.6) %). Participants with HbA1c ≥ 9% showed a significant reduction(ΔHbA1c − 0.50 (− 3.80–1.00) %; p = 0.014), while those < 9% had a mild increase(ΔHbA1c 0.10 (− 0.90–5.30) %). Night-time (03:00 AM) blood glucose levels decreased significantly across the three time points (p = 0.007), more prominently in the higher HbA1c group. NRS improved markedly (p < 0.001), though PedsQL scores were unchanged. CONCLUSIONS: Switching from U100 to U300 maintained glycemic control with modest insulin dose increases. Greater benefits were observed in patients with higher baseline HbA1c, alongside reduced nocturnal glucose and injection pain.U300 appears to enhance comfort and nighttime stability in pediatric T1D. CLINICAL TRIAL NUMBER: Not applicable.