At-Home Use of a Pregnancy-Specific Zone-MPC Closed-Loop System for Pregnancies Complicated by Type 1 Diabetes: A Single-Arm, Observational Multicenter Study

Abstract

Objective: There are no commercially available hybrid closed-loop insulin delivery systems customized to achieve pregnancy-specific glucose targets in the U.S. This study aimed to evaluate the feasibility and performance of at-home use of a zone model predictive controller-based closed-loop insulin delivery system customized for pregnancies complicated by type 1 diabetes (CLC-P).

Research design and methods: Pregnant women with type 1 diabetes using insulin pumps were enrolled in the second or early third trimester. After study sensor wear collecting run-in data on personal pump therapy and 2 days of supervised training, participants used CLC-P targeting 80-110 mg/dL during the day and 80-100 mg/dL overnight running on an unlocked smartphone at home. Meals and activities were unrestricted throughout the trial. The primary outcome was the continuous glucose monitoring percentage of time in the target range 63-140 mg/dL versus run-in.

Results: Ten participants (HbA1c 5.8 ± 0.6%) used the system from mean gestational age of 23.7 ± 3.5 weeks. Mean percentage time in range increased 14.1 percentage points, equivalent to 3.4 h per day, compared with run-in (run-in 64.5 ± 16.3% versus CLC-P 78.6 ± 9.2%; P = 0.002). During CLC-P use, there was significant decrease in both time over 140 mg/dL (P = 0.033) and the hypoglycemic ranges of less than 63 mg/dL and 54 mg/dL (P = 0.037 for both). Nine participants exceeded consensus goals of above 70% time in range during CLC-P use.

Conclusions: The results show that the extended use of CLC-P at home until delivery is feasible. Larger, randomized studies are needed to further evaluate system efficacy and pregnancy outcomes.

Conflict of interest statement

Duality of Interest. Y.C.K. has received research and product support paid to his institution from Tandem Diabetes Care, Roche Diabetes, and Dexcom, Inc. C.J.L. has received research support and supplies from Insulet Corporation, Abbott Diabetes, Tandem Diabetes Care, and Dexcom, Inc. paid to her institution and has received consulting fees from Dexcom, Inc. and Eli Lilly and Company. B.O. is currently an employee of Insulet Corporation. Work performed on this study was part of her academic appointment at Harvard University and is independent of her employment with Insulet Corporation. K.C. has received research support paid to her institution from Insulet Corporation, Abbott, Medtronic Diabetes, and Eli Lilly and Company; has received research support and supplies from Dexcom, Inc.; and has received consulting fees from Dexcom, Inc. and Abbott Diabetes. G.O., C.M.L., and S.O. have received research supplies and support paid to their institution from Tandem Diabetes Care, Insulet Corporation, Abbott Diabetes, and Dexcom, Inc. W.K.K. has received research funding from AstraZeneca, Roche, and Biogen. J.E.P. is an employee and shareholder of Tandem Diabetes Care. Participation on this project was performed while he was an employee of Sansum Diabetes Research Institute. F.J.D. reports equity and licensed intellectual property (IP), and is a member of the Scientific Advisory Board of Mode AGC. E.D. has received personal fees from Roche and Eli Lilly and Company; holds patents on artificial pancreas technology; has received product support from Insulet Corporation, Tandem Diabetes Care, Roche, and Dexcom, Inc.; and is currently an employee and shareholder of Eli Lilly and Company. The work presented in this article was performed as part of his academic appointment and is independent of his employment with Eli Lilly and Company. No other potential conflicts of interest relevant to this article were reported.

© 2023 by the American Diabetes Association.

Figures

Graphical abstract

Figure 1

Median continuous glucose monitoring glucose values during run-in versus CLC-P use. Comparison of glucose levels based on continuous glucose monitoring data between CLC-P (solid lines indicating median, and green shading indicating interquartile range) and run-in (dashed lines indicating median, and yellow shading indicating interquartile range). To convert values for glucose to millimoles per liter, multiply by 0.05551.

Figure 2

Individual participant times spent in target range and above target range, mean glucose, and time spent below target range. A: Percent time spent in the target range 63–140 mg/dL (line) and above the target range (circle size). B: Mean continuous glucose monitoring–measured glucose (line) and percent time spent below the target range (circle size). Each participant’s data are depicted with a separate color, and individual results are provided in Supplementary Material. The same color is used for the same participants throughout the panels. To convert values for glucose to millimoles per liter, multiply by 0.05551.