Comparison of fingerstick hemoglobin A1c levels assayed by DCA 2000 with the DCCT/EDIC central laboratory assay: results of a Diabetes Research in Children Network (DirecNet) Study.
BACKGROUND
The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) high-performance liquid chromatography (HPLC) method for measuring hemoglobin A1c (HbA1c) serves as a reference standard against which other assays are compared. The DCA 2000 + Analyzer (Bayer Inc., Tarrytown, NY, USA), which uses an immunoassay, is a very popular device for measuring HbA1c levels in pediatric diabetes practices.


OBJECTIVE
To determine how HbA1c values measured with the DCA 2000 in a multisite, pediatric diabetes clinic setting compare with corresponding HbA1c values measured in the DCCT/EDIC laboratory.


METHODS
To examine this question, the Diabetes Research in Children Network (DirecNet) used the DCA 2000 in five clinical centers to measure baseline HbA1c levels in 200 youth with type 1 diabetes mellitus (T1DM) (aged 12.5 +/- 2.8 yr) who were participating in an outpatient clinical trial. At the same visit, an additional blood sample was obtained, refrigerated, and shipped to the DCCT/EDIC central laboratory for determination of HbA1c values.


RESULTS
The central laboratory HbA1c value averaged 8.0 +/- 0.9% (mean +/- SD), with a median (25th and 75th quartiles) of 7.8% (7.3 and 8.5%, respectively). The DCA 2000 HbA1c values were strongly correlated (r = 0.94, p < 0.001), but significantly higher than DCCT/EDIC central laboratory values with a mean difference of +0.2% (95% confidence interval +0.14 to 0.23%, p < 0.001). There was some variation in the differences between DCA 2000 and central laboratory values at the five clinical centers (p < 0.001) with mean differences ranging between 0.0 and 0.3%, but differences between the two methods did not vary significantly by age or gender.


CONCLUSIONS
Measurements of HbA1c by the DCA 2000 compare favorably with the DCCT/EDIC central laboratory method, albeit with slightly higher values.
Tamborlane
William V
WV
Jaeb Center for Health Research, Tampa, FL 33647, USA. direcnet@jaeb.org
Kollman
Craig
C
Steffes
Michael W
MW
Ruedy
Katrina J
KJ
Dongyuan
Xing
X
Beck
Roy W
RW
Chase
Peter
P
Fox
Larry A
LA
Wilson
Darrell M
DM
Tsalikian
Eva
E
D000293:Adolescent; D001774:Blood Chemical Analysis / Q000295:instrumentation* / Q000379:methods*; D002648:Child; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D005260:Female; D005385:Fingers / Q000098:blood supply*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000592:standards; D008297:Male; D012015:Reference Standards
D006442:Glycated Hemoglobin