Comparison Between A1C and Fructosamine
A1C and Fructosamine are both tests used to monitor blood sugar levels in people with diabetes. While A1C provides a longer-term view of blood sugar levels, typically over 2-3 months, Fructosamine gives a shorter-term view, usually over 2-3 weeks. Both tests are crucial in diabetes management, but they offer different perspectives on blood sugar control.
What Is Fructosamine?
Fructosamine is a compound formed when glucose binds to protein molecules in the blood. This process is known as glycation. The process and formation of fructosamine occurs non-enzymatically, it involves a labile Schiff base intermediate and the Amadori rearrangement [1]. In particular, it is a result of the reaction between free glucose and biogenic amines such as amino acids, polypeptides or aminophospholipids [2].
Fructosamine is present in all living organisms. In fact, it is a crucial structure in the Maillard reaction, which is responsible for the organoleptic and nutritional value of thermally processed foods [2].
In addition, it is used as a marker of glucose control, as it can reflect the average blood glucose levels over the preceding 2-3 weeks [3]. We can use the concentration of fructosamine in the blood to be informed about a person’s average blood glucose levels over the said 2-3 weeks [1]. Hence fructosamine can be a useful tool for monitoring glycemic controls in individuals with diabetes [4, 3].
However, it's important to note that fructosamine levels can be influenced by factors other than blood glucose levels, such as protein levels and certain health conditions [5].
What Is A1c?
A1c is also known as the glycated hemoglobin, glucosylated hemoglobin, hemoglobin A1C or HbA1 test. It is a known blood test used to diagnose diabetes, both types 1 and type 2 [6].
The way this test works is that it measures the percentage of hemoglobin proteins in your blood cells that carries oxygen to the body [7].
The test reflects the average blood sugar levels for the past 2-3 months [6]. The higher the A1c levels are, the poorer your blood sugar control is and your risk of diabetes complication is higher [6].
The A1c test is also used to monitor how well you are managing blood sugar levels when you have diabetes [6]. It's a cornerstone blood test used in diabetes management since the 1990s [8]. However, it's important to note that while the A1c test provides a useful means of evaluating the degree of diabetic control, it doesn't tell the whole story when it comes to how well you're managing your diabetes [8].
What Is the Difference Between Fructosamine and A1c?
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Fructosamine is a compound which gets measured serving as an indicator of overall glycemic control for a shorter period (typically over 2-3 weeks) [9, 10, 11]. It can reflect the average blood glucose levels over that period. The use of a shorter time frame makes measuring fructosamine important, as in some situations, information regarding short-term glucose control is important, such as in pregnancy or following a recent adjustment in diabetes medication [10]
A1c is a specific form of hemoglobin that is glycated. The A1c test measures this glycated hemoglobin in the blood and can provide the average of blood glucose levels over a longer period, typically the preceding 8 to 12 weeks [10, 11]. It is the golden standard for diabetes management and can help with assessing long-term glycemic control
Both of these tests are important and provide valuable information regarding the blood sugar levels. However note, that since they both capture different timeframes, there might be discrepancies between these tests caused by the different periods over which they reflect the average blood glucose levels as well as specific conditions which can affect the test's accuracy (this can be for instance hemoglobin variants and alterations in red blood cell lifespan)[10, 12, 13].