Assessment of insulin dose changes in pediatric patients with type 1 diabetes mellitus starting on continuous subcutaneous insulin infusion

Objective

To assess change in total daily dose (TDD) of insulin following a switch from subcutaneous (SC) injections to continuous subcutaneous insulin infusion (CSII) in pediatric patients with type 1 diabetes (T1D). Secondary objectives were to determine the change in %basal insulin, insulin to carbohydrate (I:C) ratios, insulin sensitivity factor (ISF), and HbA1c/IDAA1c.

Methods

A retrospective chart review of patients < 18 years of age who transitioned from SC to CSII at the Alberta Children’s Hospital (Calgary, Alberta, Canada) between January 2019 and March 2022.

Results

There was an increase of 0.04 units/kg/day in TDD from baseline vs 1–3 months later (p = 0.04, 95 % confidence interval (CI) [0.002, 0.072]). When stratified by age, a similar increase in TDD was observed in age 5–12 years only (p = 0.05, 95 % CI [0.0006, 0.8236]). There was a decrease in overall %basal insulin by 3 (44 % of TDD at baseline vs 41 % of TDD on CSII). (p = 0.02, 95 % CI [−5.5, −0.4]). No strengthening was seen in I:C ratios from baseline vs 1–3 months later. There was a significant strengthening of I:C ratios at all meals in the basal bolus group from 1–3 weeks to 1–3 months post-CSII; overall strengthening of ISF at both time points; and an overall HbA1c decrease −0.30 (p < 0.0001, CI [−0.45, −0.15]). Each extra year with diabetes was associated with a decrease in HbA1c by 0.07 % (p = 0.006).

Conclusions

TDD of insulin was not found to be decreased post CSII initiation and patient characteristics should be considered when changing from SC to CSII. HbA1c was significantly improved post CSII.