Symptomatic hypoglycemia is an incentive for carbohydrate intake which, in excess, can lead to rebound hyperglycemia (RH) and contribute to high glycemic variability. We examined whether an optional "urgent low soon" (ULS) alert triggered by impending hypoglycemia could mitigate RH in the real world. Sensor glucose values (SGVs) were from the G5 and G6 continuous glucose monitoring (CGM) systems (Dexcom). G5 does not offer the ULS feature; all G6 usage was with the ULS alert enabled. An RH event was defined as any series of SGVs >180 mg/dL preceded within 2 hours by a low SGV (<70 or <55 mg/dL). Event severity was defined as the area under the curve (AUC) for consecutive SGVs >180 mg/dL. Data from a convenience sample of 24,518 anonymized G5 users who transitioned to G6 and uploaded ≥30 days of data from each system in 2018 were analyzed. RH events preceded by an SGV <70 mg/dL and those preceded by an SGV <55 mg/dL were analyzed separately. For both types of RH events, the transition from G5 to G6 and its predictive alert was associated with favorable and statistically significant reductions in the mean (SD) frequency, severity, and duration RH events (Table). The ULS alert in the G6 CGM system, intended to reduce hypoglycemia, mitigates RH events in users who transition from a system without predictive alerts and may contribute to other metrics of improved glycemic control.


G. Acciaroli: Employee; Self; Dexcom, Inc. A. Parker: Employee; Self; Dexcom, Inc. Stock/Shareholder; Self; Dexcom, Inc. J. Welsh: Employee; Self; CSL Behring. S. Puhr: Employee; Self; Dexcom, Inc. T.C. Walker: Employee; Self; Dexcom, Inc. H.K. Akturk: Advisory Panel; Self; Sanofi US. Research Support; Self; Eli Lilly and Company, REMD Biotherapeutics, Senseonics.

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