title: Use of microdialysis-based continuous glucose monitoring to drive real-time semi-closed-loop insulin infusion.
abstract: Continuous glucose monitoring (CGM) and automated insulin delivery may make diabetes management substantially easier, if the quality of the resulting therapy remains adequate. In this study, a semi-closed-loop control algorithm was used to drive insulin therapy and its quality was compared to that of subject-directed therapy. Twelve subjects stayed at the study site for approximately 70 hours and were provided with the investigational Automated Pancreas System Test Stand (APS-TS), which was used to calculate insulin dosage recommendations automatically. These recommendations were based on microdialysis CGM values and common diabetes therapy parameters. For the first half of their stay, the subjects directed their diabetes therapy themselves, whereas for the second half, the insulin recommendations were delivered by the APS-TS (so-called algorithm-driven therapy). During subject-directed therapy, the mean glucose was 114 mg/dl compared to 125 mg/dl during algorithm-driven therapy. Time in target (90 to 150 mg/dl) was approximately 46% during subject-directed therapy and approximately 58% during algorithm-driven therapy. When subjects directed their therapy, approximately 2 times more hypoglycemia interventions (oral administration of carbohydrates) were required than during algorithm-driven therapy. No hyperglycemia interventions (delivery of addition insulin) were necessary during subject-directed therapy, while during algorithm-driven therapy, 2 hyperglycemia interventions were necessary. The APS-TS was able to adequately control glucose concentrations in the subjects. Time in target was at least comparable or moderately higher during closed-loop control and markedly fewer hypoglycemia interventions were required, thus increasing patient safety.
authors.affiliation: Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universität Ulm, Ulm, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Freckmann
authors.affiliation: Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universität Ulm, Ulm, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Jendrike
authors.affiliation: Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universität Ulm, Ulm, Germany stefan.pleus@uni-ulm.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Pleus
authors.affiliation: Roche Diagnostics Operations, Inc, Indianapolis, IN, USA.
authors.forename: Harvey
authors.initials: H
authors.lastname: Buck
authors.affiliation: System Design Group, Inc, Carmel, IN, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Bousamra
authors.affiliation: Roche Diagnostics Operations, Inc, Indianapolis, IN, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Galley
authors.affiliation: Cientive Group Incorporated, Indianapolis, IN, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Thukral
authors.affiliation: Roche Diagnostics Operations, Inc, Indianapolis, IN, USA.
authors.forename: Robin
authors.initials: R
authors.lastname: Wagner
authors.affiliation: Roche Diagnostics Operations, Inc, Indianapolis, IN, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Weinert
authors.affiliation: Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universität Ulm, Ulm, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Haug
mesh_terms: D000328:Adult; D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis; D015190:Blood Glucose Self-Monitoring / Q000379:methods*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D015918:Infusion Pumps, Implantable; D007328:Insulin / Q000008:administration & dosage*; D007332:Insulin Infusion Systems; D008297:Male; D017551:Microdialysis / Q000379:methods*; D008875:Middle Aged
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin
keywords: CSII; artificial pancreas; closed-loop insulin delivery; continuous glucose monitoring