Updated: October 28, 2019
A serum fructosamine test is done for the assessment of long-term glycemic control in patients with diabetes mellitus. Diabetes mellitus (DM), commonly referred to as diabetes, is a group of metabolic disorders in which there are high blood sugar levels over a prolonged period. Symptoms of high blood sugar include frequent urination, increased thirst, and increased hunger. Fructosamine levels indicate the average level of blood glucose control over the past 2-3 weeks.
Fructosamine is a glycated protein similar to HbA1c, but the fructosamine test measures glycated protein in the blood instead of glycated hemoglobin. An increased level of serum fructosamine is associated with prolonged hyperglycemia for 2-3 weeks prior to testing in individuals with diabetes mellitus. The higher the fructosamine value, the poorer the degree of glycemia control. Sugar molecules that are present in your blood stick to proteins. These proteins circulate in your bloodstream for 14 to 21 days. So the amount of sugar in your blood for that time period can be measured by this test.
As fructosamine concentrations of people with well-controlled diabetes are usually found to be normal, this is not useful as a screening test for diabetes. The main advantage of the test is that it can detect overall changes in blood glucose control within a few weeks, rather than months like HbA1c. This test can be also useful when the HbA1c measurement may be unreliable.
However, fructosamine testing for diabetes management is rarely used in clinical practice. A simple blood glucose monitoring or HbA1c testing are preferred over it.
Testing of serum fructosamine is done for monitoring of glycemic control in below cases:
The test is also used in gestational diabetes because changes can happen very quickly during pregnancy.
Fasting is not required for this test. A sample drawn from a vein or fingerstick and analyzed in a laboratory.
Normal values vary in relation to the serum albumin concentration. The ranges are 200 to 285 µmol/L, when the serum albumin concentration level is 5 g/dL. Reduction in serum albumin lowers the serum fructosamine value.
All conditions that affect serum albumin production either increased or decreased may affect the result of fructosamine testing. These include:
As high levels of ascorbic acid interfere with the fructosamine, patients should not take ascorbic acid supplements for a minimum of 24 hours prior to sample collection.