Biochemia Medica, Vol. 16 No. 1, 2006.
Review article
Hemoglobin A1c: Standardization of the “gold standard”
Marijana Vučić Lovrenčić
Elizabeta Topić
Abstract
Hemoglobin A1c (HbA1c) has been used as a "gold standard" for clinical management of diabetes mellitus for almost 30 years. A good glycemic control, expressed as HbA1c value ≤7%, today is considered to be a clinical standard for the assessment of both therapeutic efficacy and the risk for development of diabetic complications. It is also a main subject of communication between diabetologists and patients.
Variable and unstandardized methodology, different chemical entities resulting from glycation of the hemoglobin molecule, and a lack of the primary reference material significantly influenced a reliable use of HbA1c in the clinical practice. In 2002, International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has published a reference method for HbA1c. Together with the method, an analyte has been defined, and a primary, specific reference material has been produced. However, the application of the reference method has been dimmed because of the significantly lower HbA1c values, when compared to "conventional" methods. Clinical guidelines and standards have been based on the results of long-term studies where a precise, but insufficiently specific methodology was used. The possibility of lowering absolute HbA1c values, resulting from IFCC reference method implementation, has been recognized as a serious drawback in attaining and maintaining good metabolic control. Therefore, clinical diabetology has insisted vigorously in keeping existing standards.
Harmonization of HbA1c determination is a key issue of both individual patient care and evaluation of clinical research results. However, a combination of both analytical and clinical standards is implicated in pursuing this goal. Thus, a "third way" has been proposed that offers a derivation of the new parameter "mean blood glucose", representing a sublimation of the analytical advantages offered by IFCC-reference system and valuable clinical data. The aim of this article was to review the global HbA1c harmonization project, and to introduce the respective activities carried out in Croatia.
Keywords
hemoglobin A1cM; diabetes mellitus; harmonization; standardization
Hrčak ID:
11532
URI
Publication date:
15.5.2006.
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