Six Months At-Home Hybrid Closed-Loop vs. Manual Insulin Delivery with Finger-Stick Blood Glucose Monitoring in Adults with Type 1 Diabetes: A Randomized Controlled Trial

Background: Few long-term RCTs compare Hybrid Closed Loop (HCL) insulin delivery to manual (non-HCL) insulin dosing in type 1 diabetes (T1D). Objective: To examine glycemic and psychosocial outcomes in adults with T1D using HCL vs. manual insulin dosing with self-monitoring of blood glucose (SMBG) for 6 months. Methods: Adults using multiple daily injections or pumps with SMBG were randomized 1:1 after insulin dose optimization to 26 weeks of HCL (Medtronic 670G) or continuation of current therapy. The primary outcome was time in target range (70-180mg/dL) with masked CGM during the final 3 weeks. Secondary outcomes included other CGM metrics, HbA1c, treatment satisfaction (DTSQs) and diabetes distress (PAID). Intention to treat analysis was performed with ANCOVA or rank sum test. Results: HCL and control groups were well balanced at baseline (Table). At 26 weeks, mean (95% CI) CGM time in range with HCL was greater by 14.8% (11.1, 18.5), with reduced high and low glucose time, and lower HbA1c. There were no between-group differences in treatment satisfaction or diabetes distress (Table). Conclusions: HCL provided a significant and sustained glycemic benefit compared with standard therapy. Results will inform potential users and health professionals and a cost-benefit analysis may facilitate HCL access. Disclosure S.A. McAuley: Advisory Panel; Self; Medtronic. Research Support; Self; Medtronic, Roche Diabetes Care. Speaker’s Bureau; Self; Lilly Diabetes, Roche Diabetes Care. M.H. Lee: Research Support; Self; Medtronic. Speaker’s Bureau; Self; AstraZeneca, Medtronic. B. Paldus: Research Support; Self; JDRF. Speaker’s Bureau; Self; Australian Diabetes Society, Medtronic. S. Vogrin: None. M.B. Abraham: Speaker’s Bureau; Self; Lilly Diabetes. L. Bach: None. M. Burt: None. N. Cohen: Advisory Panel; Self; Abbott, AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes. Research Support; Self; Ypsomed AG. Speaker’s Bureau; Self; Novo Nordisk A/S. P.G. Colman: None. E.A. Davis: None. C. Hendrieckx: None. M. de Bock: None. J. Holmes-Walker: None. J. Kaye: Advisory Panel; Self; Abbott. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Novo Nordisk Inc. K. Kumareswaran: None. R. MacIsaac: None. R.W. McCallum: None. C.M. Sims: Stock/Shareholder; Self; Medtronic. J. Speight: Research Support; Self; Abbott, AstraZeneca, Medtronic, Sanofi-Aventis. Speaker’s Bureau; Self; American Diabetes Association, Australian Diabetes Society, Roche Diabetes Care. S. Stranks: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Sanofi-Aventis. S. Trawley: None. V. Sundararajan: None. G. Ward: None. A.C. Keech: Advisory Panel; Self; Amgen, Kowa Research Institute, Inc. Consultant; Self; Sanofi-Aventis. Speaker’s Bureau; Self; Abbott, Amgen. A. Jenkins: Advisory Panel; Self; Abbott, Medtronic. Research Support; Self; Abbott, GlySens Incorporated, Medtronic, Sanofi-Aventis. T. Jones: Other Relationship; Self; Medtronic. D.N. ONeal: None.