Haemoglobin A_1c analysis in the management of patients with diabetes: from chaos to harmony

Abstract

Effective management of patients with diabetes mellitus requires accurate assessments of blood glucose control. The best characterised marker of long term glycaemic control is whole blood haemoglobin A_1c (HbA_1c). Published clinical trials have identified quantitative and direct relationships between the HbA_1c concentration and risks of diabetic microvascular complications. However, in order to practice evidence-based medicine, assays used to measure patient samples should ideally produce values comparable to the assays used in these trials. Numerous assays using chromatographic and immunological detection methods are used around the world. This paper briefly reviews the scientific evolution of HbA_1c and its analysis, discusses the reasons why HbA_1c assay standardisation is a challenge, describes the approaches that have been adopted to harmonise HbA_1c assays, and addresses the current initiatives to standardise HbA_1c globally. These efforts have established HbA_1c as an essential component in the management of patients with diabetes mellitus and are likely to lead to the use of HbA_1c in the screening/diagnosis of diabetes.