American Diabetes Association
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Six-months of hybrid closed-loop versus manual insulin delivery with finger-prick blood glucose monitoring in adults with type 1 diabetes: a randomized, controlled trial

posted on 2020-10-14, 22:42 authored by Sybil A McAuley, Melissa H Lee, Barbora Paldus, Sara Vogrin, Martin I de Bock, Mary B Abraham, Leon A Bach, Morton G Burt, Neale D Cohen, Peter G Colman, Elizabeth A Davis, Christel Hendrieckx, D Jane Holmes-Walker, Joey Kaye, Anthony C Keech, Kavita Kumareswaran, Richard J MacIsaac, Roland W McCallum, Catriona M Sims, Jane Speight, Stephen N Stranks, Vijaya Sundararajan, Steven Trawley, Glenn M Ward, Alicia J Jenkins, Timothy W Jones, David N O’Neal, the Australian JDRF Closed-Loop Research Group

To investigate glycemic and psychosocial outcomes with hybrid closed loop (HCL) versus user-determined insulin dosing with multiple daily injections (MDI) or insulin pump i.e. standard therapy for most adults with type 1 diabetes.


Adults with type 1 diabetes using MDI or insulin pump without continuous glucose monitoring (CGM) were randomized to 26-weeks HCL (Medtronic 670G) or continuation of current therapy. The primary outcome was masked-CGM time-in-range (TIR; 70–180mg/dL) during the final 3 weeks.


Participants were randomized to HCL (n=61) or control (n=59). Baseline mean (SD) age 44.2(11.7)years; HbA1c 7.4(0.9)%, 57(10)mmol/mol; 53% were women and 51% used MDI. HCL TIR increased from (baseline) 55% (13%) to (26 weeks) 70% (10%) with the control group unchanged: (baseline) 55% (12%) and (26 weeks) 55% (13%) (difference 15%; 95% CI 11, 19%; p<0.0001). For HCL, HbA1c was lower (median [95% CI] difference −0.4% [−0.6, −0.2]; −4mmol/mol [−7, −2]; p<0.0001) and diabetes-specific positive well-being higher (difference 1.2, 95% CI 0.4, 1.9; p<0.0048) without a deterioration in diabetes distress, perceived sleep quality or cognition. Seventeen (nine device-related) vs. thirteen serious adverse events occurred in the HCL and control groups respectively.


In adults with type 1 diabetes 26 weeks of HCL improved TIR, HbA1c and their sense of satisfaction from managing their diabetes than those continuing with user-determined insulin dosing and self-monitoring blood glucose. For most people living with type 1 diabetes globally, this trial demonstrates that HCL is feasible, acceptable and advantageous.


This trial was funded by the JDRF Australian Type 1 Diabetes Clinical Research Network (3-SRA-2016-351-M-B), a special initiative of the Australian Research Council (ARC), and the National Health and Medical Research Council (NHMRC) of Australia (APP1099379). In-kind support was provided by Medtronic (HCL systems, masked CGM devices, and technical expertise with device issues), and Roche Diabetes Care (blood glucose meters for participants using MDI). We are grateful to the study volunteers for their participation. We acknowledge support by trial nurses, diabetes educators, and dietitians at the clinical sites; lead site trial nurse Sue-Anne Wyatt; DSMB members John Santamaria, Chris Cowell, Val Gebski, and Danny Liew; and central support at the University of Sydney by trial monitors, Helen Pater and Sarah Mulray, 1,5 AG assays by Dr Andrzej Januszewski, and database assistance by Dr Adrienne Kirby. SAM is supported by a JDRF Research Award (5-ECR-2017-371-A-N). JS and CH are supported by core funding to the Australian Centre for Behavioural Research in Diabetes provided by the collaboration between Diabetes Victoria and Deakin University. AJJ is supported by an NHMRC Fellowship and is a Sydney Medical School Foundation Fellow.