Glycolated Haemoglobin (HbA1c)

Last updated 03.11.12

Index

Definition

- Amount of glycated Hb in serum as a marker of serum glucose levels over life of RBC (3 months)

Indication

- DM

- Indicator of level of control

- May be used as Dx of DM2: >6.5%

Features

- Glycated Hb in RBCs reflects amount of glucose in serum

- Not sensitive but very specific

- Not appropriate in pts w haemoglobinopathies, recent blood loss/transfusion

Procedure

- Venepuncture

Results

- Normal 4-6%

- Target <7% in DM

- Fair control 7.1 – 7.9%

- Poor control 8 – 9.9%

- Very poor control >9.9%

- Falsely high

- Increased RBC life: B12 or folate def..

- Falsely low

- Reduced RBC life: G6PD def., Sickle cell, anaemia..