Basal and Bolus Insulin Distribution According to Treatment Modality: Data from SWEET Diabetes Registry

The optimal basal and bolus insulin distribution in type 1 diabetes (T1D) is still controversial. Herein, we aimed to determine the variability of basal to total daily insulin dose according to treatment modality and diabetes technologies from the Better Control in Pediatric and Adolescent Diabetes: Working to Create Centers of Reference (SWEET) registry. Methods. The study cohort was generated by using the SWEET database. Patients with T1D for at least 2 years, aged between 2.5 and 18 years, with at least one clinic visit between June 2010 and June 2021, were included in the study. Four groups were composed according to treatment modality as follows: multiple daily injections (MDI) without continuous glucose monitoring (CGM); MDI with CGM; subcutaneous insulin infusion (CSII) without CGM; and CSII with CGM. Data of the participants were analyzed and compared for each treatment modality separately.

A total of 38,956 children and adolescents were included in the study. Of the study sample, 48.6% were female, the median (range) age was 15.2 (11.9-17.2) years, and the median diabetes duration was 6.0 (3.8-9.0) years. The distribution of treatment modality was as follows: MDI without CGM, 32.9%; MDI with CGM, 18.0%; CSII without CGM, 11.7%; and CSII with CGM, 37.3%. In unadjusted data, regardless of treatment modality, all the analyses revealed a significant association between basal dose to total daily insulin dose (BD/TDD) with male gender, younger age group, and lower HbA1c, which were all related to a decreased ratio of BD/TDD (all p < 0.05). There was no association between BD/TDD and different diabetes technologies after the age, gender, and diabetes duration were adjusted.

Herein, we showed that there was an association between lower proportions of basal to total insulin and lower hemoglobin A1c in a large cross-sectional cohort of children who had T1D. There was also an association between lower BD/TDD and younger age. There was no significant difference between BD/TDD ratios under different diabetes technologies (CGM and/or CSII).