Aim: two-centre, randomised, double-blind, parallel-group trial evaluating continuous subcutaneous insulin infusion (CSII) compatibility of faster-acting insulin aspart (faster aspart) and insulin aspart (IAsp) in 37 adults (mean±SD age: 44.3±14.6 years) with type 1 diabetes (duration 24.1±12.4 years; HbA1c 7.5±0.7%) using MiniMed Paradigm® pumps with Quick-Set® or Silhouette® infusion sets. After a 2-week run-in with IAsp, subjects received faster aspart (n=25) or IAsp (n=12) for 6 weeks. Infusion basal rates were optimised during week 1. In subsequent weeks, bolus insulin delivery was optimised. Insulin compatibility was evaluated by microscopically confirmed infusion-set occlusions and the number of possible occlusions documented, prompted by indirect observations (suspicion of occlusion, leakage, unexplained hyperglycaemia). Subjects performed macroscopic evaluations of the infusion set and reservoir every 72 h and whenever occlusion was suspected; laboratory microscopic and macroscopic examinations were performed weekly.
Results: after 6 weeks, no microscopically confirmed episodes of infusion-set occlusion were observed (219 sets evaluated). Five subjects reported seven possible occlusions with faster aspart (after 1.19±0.91 days’ use) vs. none for IAsp; none were associated with suspicion of occlusion; all but one were prompted by unexplained hyperglycaemia and the remaining episode by leakage. Laboratory macroscopic and microscopic evaluation of the infusion sets, possible in three cases, showed no colour change, or particle or crystal formation. Laboratory microscopic evaluation detected minimal particles on two occasions with faster aspart, classified ‘unlikely related to insulin’ (one case each of grey-shadowed particles and one with suspected silicone particles).
Estimated mean HbA1c change from baseline to week 6 favoured faster aspart, but was not statistically significantly different from IAsp (ETD: −0.14% [95% CI: −0.40;0.11]). Similar trends were observed for fructosamine (ETD: −11.3 µmol/l [−26.4;3.8]). No safety issues were found.
Conclusion: faster aspart was compatible with CSII, with no microscopically confirmed infusion-set occlusions, and demonstrated a trend towards improved glycaemic control.