The Effect of Prior Continuous Glucose Monitoring Use on Glycemic Outcomes in the Pivotal Trial of the MiniMed 670G Hybrid Closed-Loop System

A 3-month pivotal trial using the MiniMed 670G hybrid closed-loop (HCL) system in adolescent and adult patients with type 1 diabetes (T1D), relative to a 2-week baseline run-in period, resulted in increased sensor glucose (SG) values in target range (71-180mg/dL), reduced HbA1c levels, and no events of diabetic ketoacidosis or severe hypoglycemia (Clinicaltrials.gov: NCT02463097). This brief report evaluated how prior continuous glucose monitoring (CGM) experience influenced glycemic outcomes, in the same pivotal trial. HbA1c levels and the percentage of SG values in low, high, and in-target ranges were analyzed from participants (n=124) completing the Hybrid Closed-Loop Pivotal Trial in T1D. There were 78 individuals comprising the prior CGM group and 46 comprising the no prior CGM group. Compared to baseline, HbA1c was reduced from 7.4%+/- 0.9% to 6.9%+/- 0.7% for the prior CGM group and from 7.5%+/- 0.9% to 6.8%+/- 0.5% for the no prior CGM group. For those with prior CGM experience, the mean percentage of in-target SG values increased from 66.9%+/- 12.5% to 72.6%+/- 9.1%, and for those with no prior CGM experience it increased from 66.6%+/- 11.7% to 71.5%+/- 8.5%. Similar improvement in glucose values in the low and high ranges, relative to baseline, was observed for both groups. Resulting outcomes, from baseline to study end, did not differ between each group. These findings suggest that individuals without prior CGM experience, and those already using CGM, will benefit similarly with use of the FDA-approved MiniMed 670G HCL system therapy.