Glycated haemoglobin (HbA1c) for the diagnosis of diabetes mellitus—Practical implications

Abstract

Diagnosing diabetes is a common clinical challenge. Published in this issue of the journal is the report of the WHO consultation on the use of HbA1c for the diagnosis of diabetes [1] which makes the following recommendation: HbA1c can be used as a diagnostic test for diabetes, provided that stringent quality assurance tests are in place and assays are standardised to criteria aligned to the international reference values, and there are no conditions present which preclude its accurate measurement. The report stresses that it is an addendum to the diagnostic criteria published in 2006 [2] and the recommendation on HbA1c in diagnosing diabetes does not invalidate the 2006 recommendations on the use of plasma glucose measurements to diagnose diabetes. While using HbA1c to diagnose diabetes might seem relatively straight forward, health systems and professional organisations face major challenges if they wish to adopt this recommendation without creating further confusion in an already difficult area [3]. The initial challenge is to address the two prerequisites set out in the WHO recommendation, conditions which apply equally to HbA1c for diagnosing and monitoring diabetes: