A Comparison of Postprandial Glucose Control in the Medtronic Advanced Hybrid Closed-Loop System Versus 670G
Stuart A. Weinzimer, Ryan Bailey, Richard M. Bergenstal, Revital Nimri, Roy W. Beck, Desmond Schatz, Louise Ambler-Osborn, Darja Šmigoc Schweiger, Thekla von dem Berge, Judy Sibayan, Mary L. Johnson, Peter Calhoun, Moshe Phillip, for the FLAIR Study Group, Richard M. Bergenstal, Moshe Phillip, Amy Criego, Richard M. Bergenstal, Anders L. Carlson, Thomas W. Martens, Shannon Beasley, Mary L. Johnson, Diane Whipple, Jamie Hyatt, Alina Punel, Aimee Grieme, L. Thomas, Amy B. LaFrance, Caitlin Hasledalen, Lori M. Laffel, Elvira Isganaitis, Emily Freiner, Louise Ambler-Osborn, Hannah Desrochers, Christine Turcotte, Nisha Naik, Lindsay Roethke, Margaret C. Fisher, Revital Nimri, Michal Nevo, Rachel Bello, Alona Hamou, Orna Hermon, Orit Horesh, Galit Shiovitch Mantzuri, Irit Drotz, Nava Yehiel, Rachel Naveh, Desmond Schatz, Michael J. Haller, Anastasia Albanese-O’Neill, Eleni Sheehan, Julio Leey, Madison B. Smith, Laura M. Jacobsen, Janey Adams, Jennifer Hosford, L Whyte, Tadej Battelino, Klemen Dovč, Nataša Bratina, Darja Šmigoc Schweiger, Urška Sever, Ana Gianini, Barbara Murn Berkopec, Brigita Mali, Stuart A. Weinzimer, Kate Weyman, Lori Carria, Melinda Zgorski, Thomas Danne, Torben Biester, Thekla von dem Berge, Jantje Weiskorn, Olga Kordonouri, Sarah Biester, B Aschemeier, K Remus, Nicole Pisarek, Judy Sibayan, Roy W. Beck, Thomas J. Mouse, Julie Davis, Ryan J. Bailey, Amanda Hellmann, Nicole Reese, Peter Calhoun, Heidi Strayer, Nathan Cohen, Robert Henderson, Craig Kollman, Jennifer Kennedy, William Woodall, Israel Mahr, Korey K. Hood, Guillermo Arreaza-Rubín, Thomas L. Eggerman, Neal Green, Robert Janicek, Deanna Gabrielson
Abstract
Background: We recently reported that use of an “advanced” hybrid closed-loop system reduced hyperglycemia without increasing hypoglycemia compared to a first-generation system. The aim of this analysis was to evaluate whether this improved performance was specifically related to better mealtime glycemic control. Methods: We conducted a secondary analysis of postprandial glycemic control in an open-label, multinational, randomized crossover trial of 112 participants with type 1 diabetes, aged 14–29, of the Medtronic MiniMed™ 670G hybrid closed-loop system (670G) versus the Medtronic advanced hybrid closed-loop (AHCL) system, for 12 weeks each. We compared glycemic and insulin delivery metrics over a 3 h horizon across all meals to assess system performance and outcomes. Results: Overall meal size and premeal insulin on board were similar during run-in and between 670G and AHCL arms. Compared with 670G arm, premeal, peak, and mean glucose levels were numerically lower in the AHCL arm (167 ± 23, 231 ± 23, and 177 ± 20 mg/dL vs. 175 ± 23, 235 ± 23, and 180 ± 19 mg/dL, respectively), with a trend to lower hyperglycemia level 2 in AHCL arm. Adjusting for premeal glucose level, all postmeal outcomes between 670G and AHCL were statistically similar. Prandial insulin delivery also was similar in both treatment arms (21 ± 9 vs. 23 ± 10 U), with a shift in basal/bolus ratio from 28%/71% in 670G arm to 20%/80% in AHCL arm. Conclusions: Reduced hyperglycemia with AHCL compared to 670G was not related to early postprandial glycemic excursions after adjusting for premeal glucose level (<3 h after meal), but likely to later (>3 h) postprandial or overnight improvements. Further refinements to mealtime bolus algorithms and strategies may more optimally control prandial glycemic excursions.