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Hemoglobin A1c and mean glucose in patients with type 1 diabetes: analysis of data from the Juvenile Diabetes Research Foundation continuous glucose monitoring randomized trial. Diabetes Care 2011 Mar;34(3):540-4

Date

01/27/2011

Pubmed ID

21266647

Pubmed Central ID

PMC3041177

DOI

10.2337/dc10-1054

Scopus ID

2-s2.0-79956061593 (requires institutional sign-in at Scopus site)   52 Citations

Abstract

OBJECTIVE: To determine the relationship between mean sensor glucose concentrations and hemoglobin A(1c) (HbA(1c)) values measured in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications laboratory at the University of Minnesota in a cohort of subjects with type 1 diabetes from the Juvenile Diabetes Research Foundation continuous glucose monitoring randomized trial.

RESEARCH DESIGN AND METHODS: Near-continuous glucose sensor data (≥ 4 days/week) were collected for 3 months before a central laboratory-measured HbA(1c) was performed for 252 subjects aged 8-74 years, the majority of whom had stable HbA(1c) values (77% within ± 0.4% of the patient mean).

RESULTS: The slope (95% CI) for mean sensor glucose concentration (area under the curve) versus a centrally measured HbA(1c) was 24.4 mg/dL (22.0-26.7) for each 1% change in HbA(1c), with an intercept of -16.2 mg/dL (-32.9 to 0.6). Although the slope did not vary with age or sex, there was substantial individual variability, with mean sensor glucose concentrations ranging from 128 to 187 mg/dL for an HbA(1c) of 6.9-7.1%. The root mean square of the errors between the actual mean sensor glucose concentration versus the value calculated using the regression equation was 14.3 mg/dL, whereas the median absolute difference was 10.1 mg/dL.

CONCLUSIONS: There is substantial individual variability between the measured versus calculated mean glucose concentrations. Consequently, estimated average glucose concentrations calculated from measured HbA(1c) values should be used with caution.

Author List

Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group, Wilson DM, Xing D, Beck RW, Block J, Bode B, Fox LA, Hirsch I, Kollman C, Laffel L, Ruedy KJ, Steffes M, Tamborlane WV

Author

Rosanna V. Fiallo-Scharer MD Professor in the Pediatrics department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Blood Glucose
Diabetes Mellitus, Type 1
Female
Humans
Male
Young Adult