Fructosamine is a marker of sugar control in the body reflecting the average sugar level in the blood over the previous 2–3 weeks. It is the best way for people with haemoglobin problems to check how well their body has been controlling their glucose levels over the past few weeks. This is because conditions such as sickle cell anaemia and thalassaemia can cause a lower than expected HbA1c result.
When glucose levels are raised in the blood over a period of time, glucose molecules permanently combine with proteins in the blood. These combined molecules remain for the life of the protein and provide a record of the average amount of glucose present in the blood over that time period.
The fructosamine test reflects the average glucose levels over a 2 to 3 week time period as serum proteins have a lifespan, of around 14 to 21 days.
What might a high result mean?
An elevated result indicates poor sugar control. In general, the higher the fructosamine concentration the higher the average blood glucose level.