Laurel H Messer1, Gregory P Forlenza2, Jennifer L Sherr3, R Paul Wadwa2, Bruce A Buckingham4, Stuart A Weinzimer3, David M Maahs4, Robert H Slover2. 1. Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO laurel.messer@ucdenver.edu. 2. Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO. 3. Department of Pediatrics, Yale School of Medicine, New Haven, CT. 4. Department of Pediatrics, Stanford University School of Medicine, Stanford, CA.
Abstract
OBJECTIVE: The MiniMed 670G System is the first commercial hybrid closed-loop (HCL) system for management of type 1 diabetes. Using data from adolescent and young adult participants, we compared insulin delivery patterns and time-in-range metrics in HCL (Auto Mode) and open loop (OL). System alerts, usage profiles, and operational parameters were examined to provide suggestions for optimal clinical use of the system. RESEARCH DESIGN AND METHODS: Data from 31 adolescent and young adult participants (14-26 years old) at three clinical sites in the 670G pivotal trial were analyzed. Participants had a 2-week run-in period in OL, followed by a 3-month in-home study phase with HCL functionality enabled. Data were compared between baseline OL and HCL use after 1 week, 1 month, 2 months, and 3 months. RESULTS: Carbohydrate-to-insulin (C-to-I) ratios were more aggressive for all meals with HCL compared with baseline OL. Total daily insulin dose and basal-to-bolus ratio did not change during the trial. Time in range increased 14% with use of Auto Mode after 3 months (P < 0.001), and HbA1c decreased 0.75%. Auto Mode exits were primarily due to sensor/insulin delivery alerts and hyperglycemia. The percentage of time in Auto Mode gradually declined from 87%, with a final use rate of 72% (-15%). CONCLUSIONS: In transitioning young patients to the 670G system, providers should anticipate immediate C-to-I ratio adjustments while also assessing active insulin time. Users should anticipate occasional Auto Mode exits, which can be reduced by following system instructions and reliably bolusing for meals. Unique 670G system functionality requires ongoing clinical guidance and education from providers.
OBJECTIVE: The MiniMed 670G System is the first commercial hybrid closed-loop (HCL) system for management of type 1 diabetes. Using data from adolescent and young adult participants, we compared insulin delivery patterns and time-in-range metrics in HCL (Auto Mode) and open loop (OL). System alerts, usage profiles, and operational parameters were examined to provide suggestions for optimal clinical use of the system. RESEARCH DESIGN AND METHODS: Data from 31 adolescent and young adult participants (14-26 years old) at three clinical sites in the 670G pivotal trial were analyzed. Participants had a 2-week run-in period in OL, followed by a 3-month in-home study phase with HCL functionality enabled. Data were compared between baseline OL and HCL use after 1 week, 1 month, 2 months, and 3 months. RESULTS:Carbohydrate-to-insulin (C-to-I) ratios were more aggressive for all meals with HCL compared with baseline OL. Total daily insulin dose and basal-to-bolus ratio did not change during the trial. Time in range increased 14% with use of Auto Mode after 3 months (P < 0.001), and HbA1c decreased 0.75%. Auto Mode exits were primarily due to sensor/insulin delivery alerts and hyperglycemia. The percentage of time in Auto Mode gradually declined from 87%, with a final use rate of 72% (-15%). CONCLUSIONS: In transitioning young patients to the 670G system, providers should anticipate immediate C-to-I ratio adjustments while also assessing active insulin time. Users should anticipate occasional Auto Mode exits, which can be reduced by following system instructions and reliably bolusing for meals. Unique 670G system functionality requires ongoing clinical guidance and education from providers.
Authors: Sara H Duffus; Zain Al Ta'ani; James C Slaughter; Kevin D Niswender; Justin M Gregory Journal: Diabetes Obes Metab Date: 2019-12-09 Impact factor: 6.577
Authors: Gregory P Forlenza; Laya Ekhlaspour; Marc Breton; David M Maahs; R Paul Wadwa; Mark DeBoer; Laurel H Messer; Marissa Town; Jennifer Pinnata; Geoff Kruse; Bruce A Buckingham; Daniel Cherñavvsky Journal: Diabetes Technol Ther Date: 2019-03-19 Impact factor: 6.118
Authors: Elliott W Dirr; Morgan E Urdaneta; Yogi Patel; Richard D Johnson; Martha Campbell-Thompson; Kevin J Otto Journal: Bioelectron Med (Lond) Date: 2020-07-28
Authors: Gregory P Forlenza; Laurel H Messer; Cari Berget; R Paul Wadwa; Kimberly A Driscoll Journal: Curr Diab Rep Date: 2018-09-26 Impact factor: 4.810