Continuous Glucose Monitoring Sensor Glucose Levels and Insulin Pump Infusion Set Wear-Time During Treatment with Fast-Acting Insulin Aspart: A Post Hoc Analysis of Onset 5

Abstract

Background: In the onset 5 trial, fast-acting insulin aspart (faster aspart) was noninferior to insulin aspart (IAsp) for change from baseline glycated hemoglobin at 16 weeks, when used in continuous subcutaneous insulin infusion by participants with type 1 diabetes. The aim of this post hoc analysis was to investigate whether infusion set wear-time was associated with changes in sensor glucose, measured using continuous glucose monitoring (CGM). Materials and Methods: This was a post hoc analysis of onset 5 data. Mean infusion set wear-time and duration of CGM-wearing period were assessed. Mean CGM sensor glucose 24 h before and 24 h after were used to calculate the before-after difference (CGM sensor glucose drift). Results: Mean infusion set wear-time was 2.9 and 3.0 days in the faster aspart and IAsp arms, respectively. At 16 weeks, the average duration of the CGM wearing period was 13.7 and 13.8 days, respectively. Mean CGM sensor glucose before versus after an infusion set change, at week 16, was 10.14 versus 9.39 mmol/L with faster aspart and 9.48 versus 9.47 mmol/L with IAsp. The estimated treatment difference in CGM sensor glucose drift at 16 weeks for faster aspart versus IAsp was +0.72 mmol/L (95% confidence interval: 0.48-0.96, P < 0.001). Conclusions: Mean infusion set wear-time and duration of CGM-wearing period were similar for faster aspart and IAsp. A significantly greater upward drift in CGM sensor glucose values measured during an infusion set wearing period was observed with faster aspart versus IAsp. Clinical trial registration: NCT02825251.

Keywords: Continuous glucose monitoring; Continuous subcutaneous insulin infusion; Faster aspart; Glycemic control; HbA1c; Infusion set; Insulin pump; Postprandial blood glucose; Prandial insulin; Type 1 diabetes.

FIG. 1.

Illustration of how the mean CGM sensor glucose before and after an infusion change were calculated for each participant, when restricting to wear-times to ≥24 h. Mean CGM sensor glucose 24 h before an infusion set change is calculated using all of the CGM sensor glucose values in the hashed areas. Mean CGM sensor glucose 24 h after an infusion set change is calculated using all of the CGM sensor glucose values in the hashed solid gray areas. Only CGM sensor glucose data from periods in which the infusion set was worn for ≥24 h were included in the analysis. CGM, continuous glucose monitoring.

FIG. 2.

Distribution of infusion set wear-times. IQR, interquartile range.

FIG. 3.

Distribution of timing of infusion set change by treatment arm. Faster aspart, fast-acting insulin aspart; IAsp, insulin aspart.

FIG. 4.

Median and interquartile range of CGM sensor glucose values by treatment before and after infusion set change at 16 weeks, restricted to wear-times ≥24 h. CGM, continuous glucose monitoring; faster aspart, fast-acting insulin aspart; IAsp, insulin aspart; IQR, interquartile range.

FIG. 5.

Statistical analysis of CGM sensor glucose drift over a typical wearing period at 16 weeks, restricted to wear-times ≥24 h. For needle length, tubing length, and infusion set types participants who were dispensed a given type throughout the trial were assigned to that category; participants dispensed multiple types are assigned to the “various” category. Treatment differences were estimated using ANCOVA. The CGM sensor glucose drift is the within-participant difference in mean CGM sensor glucose over all 24-h periods before versus 24-h periods after an infusion set change. ANCOVA, analysis of covariance; BMI, body mass index; CGM, continuous glucose monitoring; CI, confidence interval; ETD, estimated treatment difference.