Visual Abstract

Objective: Insulin degludec (IDeg) is an ultra-long acting insulin that gives more flexibility with dose timing. Studies comparing the efficacy of IDeg to insulin glargine (IGlar) have conflicting results. Our aim was to compare glycemic control (HbA1c and fasting glucose) and complications (hypoglycemia, DKA) before and after switch from IGlar to IDeg in a larger sample over a longer (up to 3 years) time period.

Methods: Retrospective chart review from 2016-2020 was performed for patients with T1D ≤18 years old who switched from IGlar to IDeg. IRB approval was obtained with waiver of consent. Repeated measures analysis was performed on unbalanced data, with paired analysis of group effect on DKA and hypoglycemia.

Results: There were 88 patients that met inclusion criteria. At switch, mean (SD) diabetes duration was 6.2 (3.4) years, HbA1c 9.8 (2.1)%. Mixed modelling showed no effect of insulin switch on glycemic control. There were fewer hypoglycemic episodes on IGlar. There were fewer patients with DKA in 6 months after switch to IDeg than 6 months prior on IGlar (6.8% vs. 15.9%, McNemar p-value: <0.0001).

Conclusions: Although there was no change in glycemic control, patients with suboptimally controlled T1D had significantly less DKA after switch to IDeg than while on IGlar. Increased hypoglycemia after switch may be due to improved adherence with daily dosing.


P. Chilukoti: None. S. Malay: None. M. Finkler: None. J. R. Wood: Research Support; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Insulet Corporation, Speaker’s Bureau; Self; Xeris Pharmaceuticals, Inc. S. A. Macleish: Advisory Panel; Self; Insulet Corporation.

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at