INSULIN PUMP THERAPY REDUCES THE SEASONAL HBA1C DRIFT IN CHILDREN WITH TYPE 1 DIABETES

Glycated hemoglobin A1c (HbA1c) levels are known to fluctuate seasonally in children with Type 1 Diabetes (T1D), typically decreasing during warmer months and increasing during colder months. Given that continuous subcutaneous insulin infusion (CSII) may lower HbA1c by approximately 0.3% (3 mmol/mol) relative to multiple daily insulin injections (MDI), the well-documented seasonal drift might offset the immediate benefits of initiating CSII in warm seasons. This study examines how CSII and MDI each modulate the expected rise in HbA1c from warmer to colder weather. Materials and methods: A total of 504 T1D patients under 18 years old attending the pediatric diabetes department of a major university hospital were evaluated. Exclusion criteria included disease duration under 1 year, lack of continuous glucose monitoring (CGM) access, fewer than 6 months on CSII, or incomplete data. Propensity score matching was used to yield two groups (CSII versus MDI), matched by age, HbA1c, body mass index, and calendar month (n=65 in each group). Follow-up visits occurred at 180 +/- 90 days after baseline. Results: Follow-up time was comparable in both groups (174 +/- 35 days for CSII vs. 169 +/- 38 days for MDI, p=0.44). Children in the CSII group demonstrated no significant change in HbA1c between baseline and follow-up. Conversely, the MDI group exhibited a statistically significant increase in HbA1c at follow-up (7.58 +/- 1.0%; p=0.01 vs. baseline). Among adolescents, the same pattern emerged, indicating a stable HbA1c level in the CSII group and a marked rise in MDI users (p=0.01). Conclusions: Children receiving MDI experienced the expected seasonal HbA1c increase, whereas CSII users did not demonstrate significant changes. These findings highlight the potential buffering role of CSII on seasonal HbA1c drift, even when follow-up conditions and baseline characteristics are comparable