Background: Ultra-fast-acting insulins, such as fast-acting insulin aspart (faster aspart), have pharmacokinetic properties that may be advantageous for patients using continuous subcutaneous insulin infusion (CSII), provided that they are compatible with and safe to use in CSII.
Methods: Randomized, double-blind, parallel-group, actively controlled trial evaluating compatibility, efficacy, and safety of faster aspart in adults with type 1 diabetes using their own MiniMed Paradigm pump with Quick-Set or Silhouette infusion sets. Following run-in, subjects were randomized (2:1) to faster aspart (n = 25) or insulin aspart (n = 12) for 6 weeks. Primary endpoint was the number of microscopically confirmed episodes of infusion-set occlusions.
Results: No microscopically confirmed episodes of infusion-set occlusions were observed in either arm. Seven possible infusion-set occlusions were reported by five subjects (all faster aspart); none were prompted by a plug observed by the subject (prompted by unexplained hyperglycemia [n = 6] or leakage [n = 1]) and none were confirmed. Macroscopic and microscopic evaluation showed no color change or particle/crystal formation in the infusion sets. Premature infusion-set changes were reported in 44% and 16.7% of subjects in the faster aspart and insulin aspart groups, respectively. A nonsignificant trend toward better efficacy was observed with faster aspart (estimated treatment difference [ETD] [95% CI] in HbA1c change: -0.14% [-0.40, 0.11]). No new safety issues were found in either treatment group.
Conclusions: Over 6 weeks of treatment, no microscopically confirmed infusion-set occlusions were observed for faster aspart or insulin aspart, indicating similar compatibility with CSII use.
Keywords: infusion set occlusion; insulin pump; rapid-acting insulin; safety; type 1 diabetes mellitus.