To Örebro University

Introduction: Pump usage is widespread among Swedish children and adolescents with diabetes. However, there is a considerable variation in pump usage between clinics. Over many years, mean HbA1c in pump and injection users has been at almost the same level In Sweden. In pediatric care, we have used the more physiologic Time In Tight Range (TITR, 3.9-7.8 mmol/l, 70-140 mg/dl). TIR 70% equals ~ TITR 50%.

Objectives: The aim of this study was to investigate how pump usage relates to TITR and HbA1c in Swedish pediatric clinics.

Methods: The Swedish National Diabetes Register (NDR) collects pediatric data every ~3 months and has > 95% coverage up to age 18 years. We used online data (“Knappen” at ndr.registercentrum.se), extracting the latest available center HbA1c and CGM data that included ≥ 70% of the time, capturing percentage of patients with TITR ≥ 50% (TITR50).

Results: The national mean HbA1c was in March 2024 52.4±0.2 mmol/mol (range 45.8-56.5) (6.6%, 6.4-7.4). For pump users it was 52.1±0.2 mmol/mol (range between clinics 45.4-56.5) (6.9, 6.3-7.4) and for injections 53.7±0.6 (range 47.5-61.7) (7.1%, 6.5-7.8). Pump usage varied from 37 to 95% between clinics while the remainder of patients used multiple daily injections. There was a significant positive correlation between clinic pump usage and TITR50 (figure), but not with HbA1c. However, there was a wide variation in pump usage between clinics that managed to have percentage with TITR above 50%. NDR does not display online data on time below or above range, which is a limitation.

Conclusions: Although both are taken at the same time, HbA1c reflects the metabolic control over 2-3 months while TITR only mirrors the past 2 weeks. The significant correlation between percentage of clinic pump use and time above TITR50 indicates that although mean glucose and HbA1c may be at similar levels, injection users seem to have more values below and above 3.9-7.8 mmol/l. Both HbA1c and TITR are valuable for evaluation at clinic visits.