INSULIN PUMP THERAPY REDUCES THE SEASONAL HBA1C DRIFT IN CHILDREN WITH TYPE 1 DIABETES
DOI:
https://doi.org/10.22551/drdgbc60Abstract
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.
References
1. Ioacara S, Sava E, Georgescu O, Sirbu A, Fica S. Recent diabetes-related mortality trends in Romania. Acta Diabetol. 2018; 55(8): 821-826.
2. Hill NR, Peters CJ, Thompson RJ, Matthews DR, Hindmarsh PC. Cyclical variation in hba1c values during the year: Clinical and research implications. Diabetes Care 2013; 36(10): e175-176.
3. Mianowska B, Fendler W, Szadkowska A, et al. HbA1c levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions. Diabetologia 2011; 54(4): 749-756.
4. Sakura H, Tanaka Y, Iwamoto Y. Seasonal fluctuations of glycated hemoglobin levels in Japanese diabetic patients. Diabetes Res Clin Pract 2010; 88(1): 65-70.
5. Higgins T, Saw S, Sikaris K, et al. Seasonal Variation in Hemoglobin A1c: Is It the Same in Both Hemispheres? [Internet]. 2009. Available from: www.journalofdst.org
6. Gerstl EM, Rabl W, Rosenbauer J, et al. Metabolic control as reflected by HbA1c in children, adoles-cents and young adults with type-1 diabetes mellitus: combined longitudinal analysis including 27,035 patients from 207 centers in Germany and Austria during the last decade. Eur J Pediatr 2008; 167(4): 447-453.
7. Hathout EH, McClintock T, Sharkey J, et al. Glycemic, Auxologic, and Seasonal Aspects of Continu-ous Subcutaneous Insulin Infusion Therapy in Children and Young Adults with Type 1 Diabetes. Di-abetes Technol Ther 2003; 5(2): 175-181.
8. Nordfeldt S, Ludvigsson J. Seasonal Variation of HbA1c in Intensive Treatment of Children with Type 1 Diabetes. Journal of Pediatric Endocrinology and Metabolism 2000; 13(5): 529-535.
9. Tseng CL, Brimacombe M, Xie M, et al. Seasonal Patterns in Monthly Hemoglobin A1c Values. Am J Epidemiol 2005; 161(6): 565-574.
10. Pereira MTRP, Lira D, Bacelar C, Oliveira JC, De Carvalho AC. Seasonal variation of hemoglobin A1c in a Portuguese adult population. Arch Endocrinol Metab 2015; 59(3): 231-235.
11. Samuelsson U, Carstensen J, Löfman O, Nordfeldt S. Seasonal variation in the diagnosis of type 1 diabetes in south-east Sweden. Diabetes Res Clin Pract 2007; 76(1): 75-81.
12. Moltchanova E V, Schreier N, Lammi N, Karvonen M. Seasonal variation of diagnosis of Type 1 diabetes mellitus in children worldwide. Diabetic Medicine 2009; 26(7): 673-678.
13. Matthews CE, Freedson PS, Hebert JR, et al. Seasonal Variation in Household, Occupational, and Leisure Time Physical Activity: Longitudinal Analyses from the Seasonal Variation of Blood Choles-terol Study. Am J Epidemiol 2001; 153(2): 172-183.
14. Tucker P, Gilliland J. The effect of season and weather on physical activity: A systematic review. Public Health 2007; 121(12): 909-922.
15. Walker BR, Best R, Noon JP, Watt GCM, Webb DJ. Seasonal Variation in Glucocorticoid Activity in Healthy Men. J Clin Endocrinol Metab 1997; 82(12): 4015-4019.
16. Roche EF, Lewy H, Hoey HMCV, Laron Z. Differences Between Males and Females in the Seasonal-ity of Birth and Month of Clinical Onset of Disease in Children with Type I Diabetes Mellitus in Ire-land. Journal of Pediatric Endocrinology and Metabolism 2003; 16(5): 779-782.
17. Kristal-Boneh E, Froom P, Harari G, Malik M, Ribak J. Summer-Winter Differences in 24 h Variability of Heart Rate. European Journal of Cardiovascular Risk. 2000; 7(2): 141-146.
18. Bittel JH. Heat debt as an index for cold adaptation in men. J Appl Physiol 1987; 62(4): 1627-1634.
19. Hansen ÅM, Garde AH, Skovgaard LT, Christensen JM. Seasonal and biological variation of urinary epinephrine, norepinephrine, and cortisol in healthy women. Clinica Chimica Acta 2001; 309(1): 25-35.
20. Tanaka K, Meguro S, Itoh A, Kodani N, Itoh H. Impact of coronavirus disease 2019 in seasonal variation of hemoglobin A1c in adults with type 1 diabetes and the effect of the mode of treatment: a single-center retrospective study for 2019 and 2021 and analysis by the mode of treatment. Endocr J 2023; 70(8): 787-795.
21. Fendler W, Baranowska AI, Mianowska B, Szadkowska A, Mlynarski W. Three-year comparison of subcutaneous insulin pump treatment with multi-daily injections on HbA1c, its variability and hospital burden of children with type 1 diabetes. Acta Diabetol 2012; 49(5): 363-370.
22. Hanberger L, Åkesson K, Samuelsson U. Glycated hemoglobin variations in pediatric type 1 diabetes: The impact of season, gender and age. Acta Paediatrica, International Journal of Paediatrics 2014; 103(4): 398-403.

Additional Files
Published
Issue
Section
License
Copyright (c) 2025 The Medical-Surgical Journal

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
COPYRIGHT
Once an article is accepted for publication, MSJ requests a transfer of copyrights for published articles.
COPYRIGHT TRANSFER FORM FOR
REVISTA MEDICO-CHIRURGICALĂ A SOCIETĂȚII DE MEDICI ȘI NATURALIȘTI DIN IAȘI /
THE MEDICAL-SURGICAL JOURNAL OF THE SOCIETY OF PHYSICIANS AND NATURALISTS FROM IASI
We, the undersigned authors of the manuscript entitled
_____________________________________________________________________________________
_____________________________________________________________________________________
warrant that this manuscript, which is submitted for publication in the REVISTA MEDICO-CHIRURGICALĂ, has not been published and it is not under consideration for publication in another journal.
- we give the consent for publication in the REVISTA MEDICO-CHIRURGICALĂ, in printed and electronic format and we transfer unconditioned and complete the copyright of this manuscript to the REVISTA MEDICO-CHIRURGICALĂ, in the event of its acceptance.
- the manuscript does not break the intellectual property rights of any other person.
- we have read the submitted version of the manuscript and we are fully responsible for the content.
Names and signatures of authors / copyright owners (the following sequence is the authorship of the article):
- ______________________________/_________________________
- ______________________________/_________________________
- ______________________________/_________________________
N.B. All the authors must sign this form