Visual Abstract
Aim: CGM can predict and reduce hypoglycemia in persons with T1D by providing real-time (RT) glucose levels and trend arrows. Using CGM data, one can assess glycemic variability with coefficient of variation for glucose (CV, glucose SD/mean x 100%). Current guidelines target a CV ≤36, given its association with reduced occurrence of hypoglycemia.
Methods: As glycemic levels fluctuate across the lifespan, we aimed to evaluate associations between CV and hypoglycemia (time below range [TBR] <70 and <54 mg/dL) in 3 US studies evaluating CGM in persons with T1D (SENCE [N=143, 2-6y]/CITY [N=152, 14-24y]/WISDM [N=203, 60-86y]). Mean hours of CGM for each participant was over 300 hours at baseline and over 500 hours at the 12-month follow up period. Analyses accounted for non-normal distributions of TBR.
Results: Across all studies, higher CV was associated with more TBR (all p<.0001), with higher correlations in younger cohorts (Table). When CV>36 vs. CV≤36, TBR was higher in all 3 cohorts (p<.0001). From ~2 weeks of baseline, masked CGM data collected before starting RT-CGM to 12 months after RT-CGM initiation, proportion achieving CV≤36 increased from 13 to 31%, 21 to 35%, and 20 to 55% in SENCE, CITY, and WISDM, respectively, (all p≤.01).
Summary: CGM use helped to reduce CV and TBR over time. These 3 studies affirm that glycemic variability (CV) relates to hypoglycemia across the lifespan in T1D.
B. A. Cooper: Speaker’s Bureau; Self; Regeneron Pharmaceuticals Inc. K. Miller: Other Relationship; Self; Dexcom, Inc., Tandem Diabetes Care, Research Support; Self; JDRF, Leona M. and Harry B. Helmsley Charitable Trust. L. M. Laffel: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Dexcom, Inc., Dompe, Insulogic LLC, Janssen Pharmaceuticals, Inc., Laxmi Therapeutic Devices, LifeScan, Lilly Diabetes, Medtronic, Provention Bio, Inc.
National Institute of Diabetes and Digestive and Kidney Diseases (P30DK036836); The Leona M. and Harry B. Helmsley Charitable Trust
