Global standardization of glycated hemoglobin measurement: the position of the IFCC Working Group

Abstract

The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patients with diabetes. There are at least 30 different laboratory assays commercially available to measure the proportion of HbA1c in blood. In 1995 the IFCC established a Working Group (IFCC WG-HbA1c) to achieve international standardization of HbA1c measurement. The main achievements can be summarized as follows: a) a reference measurement procedure has been established with purified primary calibrators; b) a network of reference laboratories has been developed worldwide; and c) work has begun on implementation of traceability to the IFCC reference system. The IFCC WG-HbA1c recognizes the recommendation of the IFCC-IUPAC Committee on Nomenclature, Properties and Units that the analyte measured by the IFCC reference measurement procedure has been defined as betaN1-deoxyfructosyl-hemoglobin and that the recommended measurement units are mmol/mol. The IFCC WG-HbA1c recommends maintaining the use of the name HbA1c in clinical practice.

A history of HbA1c through Clinical Chemistry and Laboratory Medicine

“…Indications were given regarding the standardization process, the change of units and the terminology used [87,88] . Indeed, the adoption of the new IFCC reference method implied different changes in result management.…”

Clinical applications of glycosylated haemoglobin

“…This could possibly result in clinicians either under-treating or over-treating patients because older targets are still being used. [36][37][38][39][40][41] It was also suggested that rather than migrating to these IFCC values, the HbA1c could be expressed as a ''mean plasma glucose equivalent'', or, as it has recently been coined, ''estimated average glucose'' (eAG). There was much debate over whether to report HbA1c results in the traditional DCCT/UKPDS/NGSP units that most clinicians were familiar with or in the accuracy based IFCC units.…”

Glycemic control in the clinical management of diabetic patients

“…In the specific case of HbA 1c , the whole chain has been defined [ 16 ], primary materials have been prepared and characterized [ 17 ], an IFCC-approved reference method has been developed [ 18 ], and a network of reference laboratories has been created [ 19 ]. Close cooperation between the manufacturers and the IFCC Network has been in place for several years with a dedicated EQAS, the IFCC Monitoring Program [ 20 ].…”