The CGM Intervention in Teens and Young Adults (CITY) trial demonstrated reductions in hemoglobin A1c (HbA1c) and hypoglycemia using CGM compared with intermittent blood glucose monitoring over a 6-month period. To determine if this improvement would be sustained, we evaluated outcomes in participants who continued CGM use through 12 months. The study was completed by 70 of 74 (95%) in the CGM group (43% female, median age 17 yrs, 67% non-Hispanic white, and 47% insulin pump users). Central-lab measured HbA1c and CGM measured glycemic outcomes at 12 months were compared with baseline (CGM at baseline was masked). HbA1c decreased from 8.9% at baseline to 8.3% at 12 months (p<0.001) (Table). Time spent in range 70-180 mg/dL was 38% at baseline and 41% at 12 months (P=0.3). Median percent time <70 mg/dL was reduced from 3.4% (49 min/day) at baseline to 1.1% (16 min/day) at 12 months (p<0.001). Similar improvements were observed for time <54 mg/dL with a decrease from a median of 1.0% (14 minutes/day) at baseline to 0.1% (<2 minutes/day) at 12 months. Glycemic variability measured by coefficient of variation was reduced from 42% at baseline to 37% at 12 months (p<0.001). These results demonstrate improvements in outcomes for teens and young adults with CGM use over a 12-month period with substantial improvements in HbA1c and reductions in hypoglycemia.


K. Miller: None. L. Kanapka: None. C. Bauza: None. L.M. Laffel: Advisory Panel; Self; Roche Diabetes Care. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Insulogic LLC, Janssen Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc., Sanofi US.


The Leona M. and Harry B. Helmsley Charitable Trust; Dexcom, Inc.

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