Evolution of HbA1c measurement over the past decade

For its 50th anniversary, the Journal Clinical Chemistry and Laboratory Medicine (CCLM) had taken up the topic HbA1c. Now , on their 60th anniversary, problems and progresses are discussed in further detail.

HbA1c was discovered in the 1960s and has since then been established as important biomarker for diagnosis of diabetes mellitus and for surveillance of various possibilities available for treatment. Despite issues concerning the parameter, many milestones have been achieved over the last decades. One of them was the implementation of a reference measurement procedure (RMP) by the International Federation of Clinical Chemistry and Laboratory Medicines (IFCC) in 2002 [1]. Since then, standardization according to the IFCC-RMP has become increasingly common, ensuring reliable traceability.

However, standardization also brought some problems: As part of the standardization process, the IFCC has recommended reporting the HbA1c value in mmolHbA1c/molHbA0+HbA1c as it corresponds to SI units. The reason for this implementation was to replace the expression in % of total Hemoglobin, as it was used by the National Glycohemoglobin Standardization Program (NGSP) in the whole world [ 2]. Even though there are different units, it leads to the same results, as they are interconvertible with the help of a master equation [3]. However, implementation is still an ongoing process.

Performance evaluation has emerged as additional topic. Several methods may be used for HbA1c measurement. The commonly used methods are based on enzymatic cleavage, immunoturbidimetry, affinity chromatography or even on cation exchange high performance liquid chromatography (HPLC). As these methods completely differ from each other, external quality assessment (EQA) becomes more and more important. Confirmation of the continuous global improvements can be received by national and international projects. Leading to an obligation of improvement among the manufacturers to fit the increasingly strict criteria.

Furthermore, HbA1c is not only important for clinical institutions. The determination by Point-of-care testing (POCT) in doctor offices gains importance. However, this requires high quality systems and well-trained personnel.

In conclusion, HbA1c is a parameter marked by a certain resilience among others. There is a need for continuous improvement to be able to compete with other innovative biomarkers.

Even though HbA1c has become the biomarker of choice, measurement of glucose is still an important pillar in diagnosis of diabetes mellitus and surveillance of therapy.

With the constant research for new parameters and the progressive improvement of existing reagents, DiaSys contributes to the progress of science.

For further information on DiaSys diabetes panel, please follow the links below:

Solutions for laboratories                          Solutions for POCT

Glucose GOD FS 10’                                        oneHbA1c IS

Glucose Hexokinase FS

oneHbA1c FS

HbA1c net FS


  1. Jeppson JO, Kobold U, Barr J, Finke A, Hoelzel W, Hoshino T, et al. Approved IFCC reference method for the measurement of HbA1c in human blood. Clin Chem 2004; 50:166-74.
  2.  Available from: https://ngsp.org/index.asp [Accessed 25 July 2023] 
  3. Hoelzel W, Weykamp C, Jeppson JO, Miedema K, Barr JR, Godall I, et al. IFCC reference system for measurement of hemoglobin A1c in human blood and the national standardization schemes in the United States, Japan and Sweden: a method-comparison study. Clin Chem 2004; 50:166-74.