Web page content
Glycosylated Haemoglobin
Fructosamine and glycosylated haemoglobin
(GHb) are two glycated proteins commonly used for monitoring diabetics.
The two proteins are markers of mean blood glucose, with their levels
being proportional to the blood glucose concentration. The concentration
of these proteins is not affected by stress; they are ideal for
monitoring diabetic animals. In practice they are particularly
useful for the diagnosis and monitoring of diabetic cats.
Glycosylated haemoglobin
is produced by the non-enzymatic, irreversible binding of glucose
to haemoglobin in erythrocytes. The glycosylation of haemoglobin
is a gradual process and is not affected by acute or transient hyperglycaemia.
Glycosylated (glycated)
haemoglobin concentration can be used as a screening test for diabetes
mellitus, as well as for the monitoring of glycemic control in treated
diabetic animals, based on red blood cell lifespan.
Advantages of
GHb measurements
- Unaffected by stress related or post-prandial hyperglycaemia.
- Useful in long term monitoring of diabetic animals over the
previous 2-3 months.
Limitations of
GHb measurements
- Test not widely available for dogs and cats
- Not the most responsive test due to the relatively long erythrocyte
lifespan life span (approximately 110 days in dogs and <68
days in cats).
- Less effective for short-term monitoring than fructosamine because
hyperglycaemia must be present for at least 3 weeks before increased
HbA1c values are detectable.
- Affected by haemoglobin concentrations: may be increased or
decreased due to polycythaemia or anaemia, respectively.