American Diabetes Association
EDIC CGM Supplement Clean 01-15-22_cx01.pdf (381 kB)

Continuous Glucose Monitoring in Adults With Type 1 Diabetes With 35 Years Duration From the DCCT/EDIC Study

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posted on 2022-01-25, 17:32 authored by Rose A. Gubitosi-Klug, Barbara H. Braffett, Ionut Bebu, Mary L. Johnson, Kaleigh Farrell, David Kenny, Victoria R. Trapani, Lynne Meadema-Mayer, Elsayed Z. Soliman, Rodica Pop-Busui, John M. Lachin, Richard M. Bergenstal, William V. Tamborlane, the DCCT/EDIC Research Group
Objective: We evaluated blinded continuous glucose monitoring (CGM) profiles in a subset of adults with type 1 diabetes from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study to characterize the frequency of glycemic excursions and contributing factors.

Research Design and Methods: CGM-derived metrics were compared for daytime and nighttime periods using blinded CGM for a minimum of 6.5 days (average 11.9 days) and correlated with HbA1c levels, routine use of diabetes devices, and other characteristics in 765 participants.

Results: Participants were 58.9±6.5 years of age with diabetes duration 36.8±4.9 years and HbA1c 7.8±1.2%; 58% used insulin pumps and 27% used personal, unblinded CGM. Compared to daytime, nighttime mean sensor glucose was lower, % time in range 70-180 mg/dL (TIR) was similar and hypoglycemia more common. Over the entire recording period, only 9% of the 765 participants achieved >70% TIR and only 28% achieved <1% of observations <54 mg/dL. Indeed, participants with the highest percentage of hypoglycemia had the lowest HbA1c levels. However, use of insulin pumps and CGM decreased the % time <54 mg/dL.

Conclusions: In adults with long-standing type 1 diabetes, short-term blinded CGM profiles revealed frequent clinically-significant hypoglycemia (<54 mg/dL) during the night and more time in hyperglycemia during the day. The small subset of participants using routine CGM and insulin pumps had fewer hypoglycemic and hyperglycemic excursions and lower HbA1c levels. Thus, strategies to lower meal-stimulated hyperglycemia during the day and prevent hypoglycemia at night are relevant clinical goals in older type 1 diabetes patients.


The DCCT/EDIC has been supported by cooperative agreement grants (1982-1993, 2012-2017, 2017-2022), and contracts (1982-2012) with the Division of Diabetes Endocrinology and Metabolic Diseases of the National Institute of Diabetes and Digestive and Kidney Disease (current grant numbers U01 DK094176 and U01 DK094157), and through support by the National Eye Institute, the National Institute of Neurologic Disorders and Stroke, the General Clinical Research Centers Program (1993-2007), and Clinical Translational Science Center Program (2006-present), Bethesda, Maryland, USA. Additional support for this study was provided by grant DP3DK106890.


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