HbA1c – DCCT / IFCC / eAG Relationship
Up to recent years, the HbA1c (glycated haemoglobin) was reported as a percentage in accordance to “The Diabetes Control and Complications Trial” (DCCT). The situation has changed as a result of a number of standardisation programmes, culminating in the work of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Working Group on Standardisation of HbA1c, which established true International Reference Methods. Hence, HbA1c results, traceable to the IFCC reference method derived, will be expressed as mmol per mol of unglycated haemoglobin.
In additon, a large international study recently produced equivalent “average glucose” (eAG) values for HbA1c expressed in mmol per Litre. This eAG, like the HbA1c, shows an estimation of the glucose levels in the preceding 2 – 3 months.
In the forthcoming weeks, Clinipath will start reporting HbA1c results in both DCCT (%) and IFCC (mmol/mol), as well in eAG (mmol/L).
IFCC DCCT eAG
Non-diabetic : 20 – 42 mmol/mol 4.0 – 6.0 % 3.8 – 7.0 mmol/L
Pre-diabetes : 43 – 47 6.1 – 6.4 7.1 – 7.6
Diabetes : > 48 > 6.5 > 7.7