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..