Evaluation of Extended Infusion Set Performance in Adults with Type 1 Diabetes: Infusion Set Survival Rate and Glycemic Outcomes from a Pivotal Trial

Abstract

Background: Standard insulin infusion sets (IISs) are to be replaced every 2 to 3 days to avoid complications and diabetic ketosis due to set failure. This pivotal trial evaluated the safety and performance of a new extended-wear infusion set (EIS) when used for 7 days by adults with type 1 diabetes (T1D). Methods: This single-arm, nonrandomized trial enrolled adults (18-80 years of age) with T1D, who used their own MiniMed™ 670G system with insulin lispro or insulin aspart and the EIS for up to 7 days, across 12 consecutive wears. Safety endpoints included incidence of serious adverse events (SAEs), serious adverse device effects (SADEs), unanticipated adverse device effects (UADEs), severe hypoglycemia (SevHypo), severe hyperglycemia (SevHyper), diabetic ketoacidosis (DKA), and skin infection. The EIS failure rate due to unexplained hyperglycemia (i.e., suspected occlusion), the overall EIS survival rate, glycemic control outcomes (i.e., A1C, mean sensor glucose and time spent in established glucose ranges), total daily insulin delivered, and satisfaction with the EIS were determined. Results: The intention to treat population (n = 259, 48% men, 45.0 ± 14.1 years) wore a total of 3041 EIS devices. No SADE, UADE, or DKA events was reported. Overall rates of SAEs, SevHypo, SevHyper, and skin infection were 3.8, 2.5, 104.1, and 20.1 events per 100 participant-years. The rate of EIS failure due to unexplained hyperglycemia at the end of day 7 was 0.1% (95% confidence interval [CI]: 0.03-0.51) and 0.4% (95% CI: 0.16-1.00) for insulin lispro and aspart use, respectively. Overall EIS survival rate at the end of day 7 was 77.8% (95% CI: 76.2-79.3), glycemic control did not change, and participants reported greater satisfaction with the EIS compared with standard IISs worn before the study (P < 0.001). Conclusions: This investigation demonstrates that the EIS, when worn for up to 7 days, was safe and rated with high satisfaction, without adversely affecting glycemic control in adults with T1D. Clinical Trial Registration number: NCT04113694 (https://clinicaltrials.gov/ct2/show/NCT04113694).

Keywords: Adults; Failure rate; Insulin infusion set; Survival rate; Time in range; Unexplained hyperglycemia.

FIG. 1.

Extended infusion set and insertion device The Medtronic extended infusion set (shown with the inserter) has several advancements relative to earlier IISs designed for 2 to 3 days of wear, which include a new (A) H-cap connector and (B) tubing with new fluid path design that improves insulin preservative retention and stability, in addition to (C) a new extended-wear adhesive patch that improves skin adherence.

FIG. 2.

Study participant disposition. *One participant wore the extended-wear infusion set (EIS), but did not meet eligibility criteria and was withdrawn from the study and designated a screen failure. EIS.

FIG. 3.

Survival rates of the extended infusion set across days of wear. The survival rates of all extended infusion sets (overall, n = 2788) worn for 7 days are shown, in addition to the survival rates when extended infusion sets were used with insulin lispro (n = 1412) and insulin aspart (n = 1376).

FIG. 4.

Satisfaction rates with standard IIS and extended infusion set use. The mean rates of satisfaction during standard IIS and extended infusion set (EIS) use for the queries of interest (top) are shown. Only participants who completed the questionnaire at both Visit 2 and the end-of-study visit were included in the paired analysis. *P < 0.001 based on the satisfaction score comparison with the previously used standard IIS (Wilcoxon signed-rank test). IIS, insulin infusion set.