Abstract

BACKGROUND: Data are limited on the need for and benefits of pump setting optimization with automated insulin delivery. We examined clinical management of a closed-loop control (CLC) system and its relationship to glycemic outcomes.MATERIALS AND METHODS: We analyzed personal parameter adjustments in 168 participants in a 6-month multicenter trial of CLC with Control-IQ vs sensor-augmented pump therapy (SAP). Preset parameters (BR=basal rates, CF=correction factors, CR=carbohydrate ratios) were optimized at randomization, 2 and 13 weeks, for safety issues, participant concerns, or initiation by participants' usual diabetes care team. Time-in-range (TIR 70-180mg/dL) was compared in the week preceding and following parameter changes.RESULTS: In 607 encounters for parameter changes, there were fewer adjustments for CLC than SAP (3.4 vs. 4.1/participant). Adjustments involved BR (CLC 69%, SAP 80%), CR (CLC 68%, SAP 50%), CF (CLC 44%, SAP 41%), and overnight parameters (CLC 62%, SAP 75%). TIR preceding and following adjustments was CLC 71.2% and 71.3% and SAP 61.0% and 62.9%. The highest baseline HbA1c CLC subgroup had the largest TIR improvement (51.2% v 57.7%). When a CR was made more aggressive in the CLC group, postprandial time above 180mg/dL was 43.1% preceding and 36.0% following the change. The median postprandial time <70mg/dL before making CR less aggressive was 1.8%, and following the change was 0.7%.CONCLUSION: No difference in TIR was detected with parameter changes overall but they may have an effect in higher HbA1c1c subgroups or following user-directed boluses suggesting changes may matter more in suboptimal control or during discrete periods of the day.

View details for DOI 10.1089/dia.2020.0472

View details for PubMedID 33155824