212-OR: Closed-Loop Increases Time-in-Range in Older Adults with Type 1 Diabetes Compared with Sensor-Augmented Pump Therapy: A Randomized Crossover Trial

Abstract

Background: Older adults with type 1 diabetes (T1D) have unique health challenges and have not been specifically studied in previous closed-loop (CL) trials. Objective: To assess the efficacy and safety of CL compared with sensor-augmented pump (SAP) therapy in older adults with T1D. Methods: We conducted a two-stage randomized, crossover trial comparing 4 months of CL vs. SAP. Adults aged ≥60 years with T1D ≥10 years and using an insulin pump were eligible. SAP (with continuous glucose monitoring [CGM] alerts and optional insulin delivery suspension on low glucose) and multi-disciplinary education were provided during run-in, then CL and SAP stages were undertaken in random order. The primary outcome was CGM time in range (TIR) 70-180 mg/dL comparing the final 3 months of each stage. Results: Thirty adults (mean±SD age 67±5 years, T1D duration 37±15 years and HbA1c 59±9 mmol/mol [7.6±0.9%]) participated. Ten participants (33%) had impaired awareness of hypoglycemia (Gold score ≥4); all were cognitively healthy, and none met the criteria for frailty. CGM TIR was 75.1±6.3% during CL and 69.0±9.1% during SAP (mean difference 6.2% [95% CI 4.3, 8.0]; p <0.001). All pre-specified CGM metrics favored CL over SAP; benefits were greater overnight. CL reduced CGM time <70 mg/dL compared with SAP during 24 h/day (median [IQR] 1.2% [0.6, 1.7] vs. 1.7% [1.0, 2.5], respectively; p <0.001) and overnight (0.4% [0.2, 0.9] vs. 1.3% [0.8, 2.5], respectively; p <0.001). HbA1c at CL vs. SAP stage end was 56 mmol/mol (54, 59) vs. 59 mmol/mol (54, 62), respectively (p = 0.11). No serious hypoglycemic events occurred; one episode of diabetic ketoacidosis occurred during SAP. Conclusions: In this trial involving adults with T1D aged ≥60 years, CL increased TIR and reduced time below range compared with SAP, particularly overnight. The therapeutic benefit was evident even with relatively low baseline HbA1c. Further research is needed to understand the long-term clinical benefit. Disclosure S. A. Mcauley: Speaker’s Bureau; Self; Sanofi. N. A. O’regan: None. V. Sundararajan: None. G. M. Ward: None. R. Macisaac: Advisory Panel; Self; AstraZeneca, Bayer Healthcare Pharmaceuticals Inc., Novo Nordisk, Servier Laboratories, Speaker’s Bureau; Self; Boehringer Ingelheim International GmbH, Novo Nordisk. S. Vogrin: None. S. Trawley: None. P. G. Colman: None. S. Fourlanos: Advisory Panel; Self; Pfizer Foundation, Speaker’s Bureau; Self; AstraZeneca, Eli Lilly and Company. C. Grills: None. M. H. Lee: None. A. Mohammad alipoor: None. D. N. O’neal: Advisory Panel; Self; Abbott Diabetes, Medtronic, Sanofi, Research Support; Self; Dexcom, Inc., GlySens Incorporated, Medtronic, Pacific Diabetes Technologies. Funding JDRF (3-SRA-2018-667-M-R); Diabetes Australia