Volume 5, Issue 1, January 2019, Page: 19-25
Hemoglobin A(1c) Reporting Units and Diagnostic Cut-Offs in Relation to International Recommendations
Penttilä Ilkka, Research Institute of Exercise Medicine, University of Eastern Finland, Haapaniementie, Kuopio, Finland
Penttilä Karri, The Finnish Medicines Agency FIMEA, Microkatu, Kuopio, Finland
Laitinen Harri, The International External Quality Assessment Schemes for, Clinical Laboratories Labquality Ltd., Kumpulankatu, Helsinki, Finland
Ranta Päivi, The International External Quality Assessment Schemes for, Clinical Laboratories Labquality Ltd., Kumpulankatu, Helsinki, Finland
Törrönen Jukka, Research Institute of Exercise Medicine, University of Eastern Finland, Haapaniementie, Kuopio, Finland
Rauramaa Rainer, Research Institute of Exercise Medicine, University of Eastern Finland, Haapaniementie, Kuopio, Finland
Received: Oct. 29, 2018;       Accepted: Jan. 9, 2019;       Published: May 20, 2019
DOI: 10.11648/j.ijcems.20190501.15      View  487      Downloads  61
Purpose. In this account were studied the use of units and cut-off limits for hemoglobin A(1c) in worldwide clinical laboratory practice and the quality assurance ranges of hemoglobin A(1c) by calculating the target limits from the values of Labquality Ltd. and ERLGH. Methods. The use of HbA(1c) units and the diagnostic limits for diabetes were examined using e-mail and letter inquiries to 37–51 societies of laboratory medicine (mainly clinical chemistry) sent from 2009 to 2017. The parametric statistical programs of Labquality Ltd., SPSS® 13.0, and MS Excel 2013 (Microsoft® Co., Cambridge, MA, USA) were used. Results. The mean values of the Finnish quality control organization Labquality Ltd. and the corresponding values from the HbA(1c) queries as to the percentage and mmol/mol SI units (IFCC) were used. The IFCC system for hemoglobin A(1c) is slowly but constantly gaining acceptance in Europe, but remains quite rare outside Europe where the percentage results were correspondingly lower. The mean round values of Labquality Ltd. and the corresponding mean values of the European Reference Laboratory for Glycohemoglobin (ERLGH) showed equal ranges for calculation of the target values with ± 6% intervals for the percentage results and ± 8% intervals for the mmol/mol results. Conclusions. To avoid confusion, the overall use of mmol/mol as a single unit for HbA(1c) may be the best option when the IFCC system has been accepted worldwide. The target values can be calculated equally well from the mean values of Labquality Ltd. and the ERLGH values in terms of both per percentage and mmol/mol units.
Diabetes, HbA(1c), IFCC Recommendation, Methods Quality Assurance, Target Limits, Units
To cite this article
Penttilä Ilkka, Penttilä Karri, Laitinen Harri, Ranta Päivi, Törrönen Jukka, Rauramaa Rainer, Hemoglobin A(1c) Reporting Units and Diagnostic Cut-Offs in Relation to International Recommendations, International Journal of Clinical and Experimental Medical Sciences. Vol. 5, No. 1, 2019, pp. 19-25. doi: 10.11648/j.ijcems.20190501.15
Copyright © 2019 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current Care Guideline for Diabetes of the working roup appointed by the Finnish Medical Society Duodecim, the Finnish Society of Internal Medicine, and the Medical Advisory Board of the Finnish Diabetes Society; www.duodecim.fi/diabetes/2017.
Penttilä I, Penttilä K, Holm P, Laitinen H, Ranta P, Törrönen J, Rauramaa R. Methods, units and quality requirements for the analysis of haemoglobin A1c in diabetes mellitus. World J Methdol 2016; 6:133-142.
Rabhar S. An abnormal hemoglobin in red cells of diabetes. Clin Chim Acta. 1968; 22:296-298.
Trivelli LA, Ranney HM, Lai H-T. Hemoglobin components in patients with diabetes mellitus. New Engl J Med. 1971; 284:353-357.
Weykamp CW, Penders TJ, Muskiet FAJ, van der Silk W. Effect of calibration on dispersion of glycohemoglobin values determined from 111 laboratories using 21 methods. Clin Chem. 1994; 40:138-144.
The EurA1c Group: The European HbA1c Trial to Investigate the Performance of HbA1c Assays in 2166 Laboratories across 17 Countries and 24 Manufacturers by Use of the IFCC Model for Quality Targets. Clin Chem 2018; 64:1183-1192.
Little RR, Rohlfing CL. Assessing quality from an accuracy-based HbA1c proficiency survey. Clin Chem 2018;64:Issue 12.
Finke A, Kobold U, Hoelzel W, Weykamp C, Miedema K, Jeppsson J-O. Preparation of a candidate primary reference material for the international standardization of HbA1c determinations. Clin Chem Lab Med. 1998; 36:299-308.
Jeppsson J-O, Kobold U, Barr J, Finke A, Hoelzel W, Hashino T, Miedema K, Mosca A, Mauri P, Paroni R, Thienpont L, Umemoto M, Weykamp C. Approved IFCC reference method for the measurement of HbA1c in human blood. Clin Chem Lab Med. 2002; 40:78-89.
Hoelzel W, Miedema K. Development of a reference system for the international standardization of HbA1c/glycohemoglobin determinations. J Int Fed Clin Chem. 1996; 9:62-67.
Hoelzel W, Weykamp C, Jeppsson J-O, Miedema K, Barr JR, Goodali I, Hoshino T, John WG, Kobold U, Little R, Mosca A, Pierluigi M, Paroni R, Susanto F, Takei I, Tienpont L, Umemoto M, Wiedmeyer H-M on behalf of the IFCC Working Group on HbA1c Standardization. IFCC reference system for measurement of HbA1c in human blood and the national standardization schemes in the United States, Japan, and Sweden: a method-comparison study. Clin Chem. 2004; 50:166-174.
American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care. 2010; 33(Suppl 1):S62-S69.
Hanas R, John WG; International HbA1c Consensus Committee. 2013 Update on the worldwide standardization of the hemoglobin A1c measurement. Pediatr Diabetes. 2014; 15:e1-e2.
Manley S, John WG, Marshall S. Introduction of IFCC reference method for calibration of HbA1c: implications for clinical care. Diabetes Med. 2004; 21:673-676.
Labquality Ltd., Finland; www.labquality.fi/2018.
Penttilä I, Penttilä K, Halonen T, Pulkki K, Törrönen J, Rauramaa R. Adaptation of the Diazyme direct enzymatic HbA1c assay for a microplate reader at room temperature. Clin Chem Lab Med. 2011; 49:1221-1223.
Weykamp C, Lenters-Westra E, van der Vuurst H, Slingerland R, Siebelder C, Visser-Dekkers W. Evaluation of the Menarini/ARKRAY ADAMS A1c HA-8180V analyzer for HbA1c. Clin Chem Lab Med. 2011; 49:647-651.
Little RR, Rohlfing CL, Sacks DB for the NGSP Committee. Status of hemoglobin A1c measurement and goals for improvement: from chaos to order for improving diabetes care. Clin Chem. 2011; 57:205-214.
Lindblad B, Nordin G. External quality assessment of HbA1c and kits effect on comparison between Swedish pediatric diabetes clinics. Experiences from the Swedish pediatric diabetes quality register (Swediabkids) and Equalis. Clin Chem Lab Med. 2013; 51:2045-2052.
Lenters-Westra E, Boraas T, Schindhelm RK, Slingerland RJ, Sandberg S. Biological variation of hemoglobin A1c: consequences for diagnosis of diabetes mellitus. Clin Chem. 2014; 60:1570-1572.
Penttilä I, Anttila P, Collings A, Hägglund H, Holm P, Hämäläinen E, Laitinen P, Leino P, Laitinen H. HbA1c tulokset yhdenmukaisiksi (To uniform the HbA1c results). Suom Lääk Lehti. 2015; 70;2016-2017.
DGKL (Deutsche Vereinte Gesellschaft für Klinische Chemie und Laboratoriums-medizin). Stellungnahme der Deutschen Diabetes Gesellschaft, diabetes und des Kompetenznetzes Diabetes mellitus zur Verwendung des HbA1c-Wertes als Biomarker zur Diabetesdiagnose; www.diabetesde.org/
Nordin G, Dybkaer R. Recommendation for term and measurement unit for “HbA1c”. Clin Chem Lab Med. 2007; 45:1081-1082.
Weykamp CW, Mosca A, Gillery P, Panteghini M. The analytical goals for hemoglobin A1c measurement in IFCC units and in National Glycohemoglobin Standardization Program units are different. Clin Chem. 2011;57:1204-1206.
Nielsen AA, Petersen PH, Green A, Christensen C, Christensen H, Brandslund I. Changing from glucose to HbA1c for diabetes diagnosis: predictive values of one test and importance of analytical bias and imprecision. Clin Chem Lab Med. 2014; 52:1069-1077.
Lenters-Westra E, English E. Evaluating new HbA1c methods for adoption by the IFCC and NGSP reference networks using international quality targets. Clin Chem Lab Med. 2017; 55:1426-1434.
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