Associations between A1C and Continuous Glucose Monitoring–Derived Glycemic Parameters

The percentage of continuous glucose monitoring (CGM)-derived sensor glucose (SG) values in the 70-180 mg/dL range (time in range [TIR]) is an important outcome for patients and their clinicians; however, consensus TIR goals are lacking. This study aimed to characterize associations between CGM-derived glycemic metrics and A1C in 4 clinical trials: DIAMOND Phase 1 (N=104), DIAMOND Phase 2 (N=69), REPLACE-BG (N=216), and HypoDE (N=141). Each study lasted ≥24 weeks, used current-generation CGM systems (Dexcom, Inc.), and included comparisons of central-lab end-of-study A1C to CGM data during the preceding 3 mo. Data from 530 adults with diabetes (455 type 1) were analyzed. The Figure shows mean SG (MSG), TIR, time 250 mg/dL for individuals in 6 A1C bins. Higher A1C bins were associated with higher MSG and lower TIR; lower A1C bins were associated with lower MSG and higher TIR. For subjects with A1C 57%. Median time with SG 250 mg/dL increased from 0.6 h/day to 6.7 h/day across bins. For subjects with A1C ≥8.0%, median TIR was 44%, with 90% of the subjects having TIR Disclosure P. Calhoun: Employee; Self; Dexcom, Inc.. Stock/Shareholder; Self; Dexcom, Inc. T. Johnson: Employee; Self; Dexcom, Inc. J. Welsh: Employee; Self; Dexcom, Inc.. Stock/Shareholder; Self; Dexcom, Inc., Medtronic. T.C. Walker: Employee; Self; Dexcom, Inc. D.A. Price: Employee; Self; Dexcom, Inc..