From the Guidelines
A fructosamine lab test is used to monitor glycemic status in people with diabetes, particularly when A1C testing is unreliable or unavailable, by measuring the average blood glucose levels over the past 2-4 weeks. This test is an alternative to A1C and is approved for clinical use, as stated in the 2024 standards of care in diabetes 1. The test measures the total glycated serum proteins, mostly albumin, which reflects glycemia over a shorter-term time frame than A1C. Some key points about fructosamine testing include:
- It is highly correlated with glycated albumin in people with diabetes, and modern assays have excellent performance 1
- It has been linked to long-term complications in epidemiologic cohort studies, although the evidence base is weaker than that for A1C 1
- It is useful for patients with conditions that interfere with A1C interpretation, such as hemolytic anemia or recent blood loss, and for rapid assessment of glycemic changes 1
- Normal values typically range from 200-285 μmol/L, though reference ranges may vary between laboratories. The fructosamine test is a valuable tool for monitoring diabetes control, especially in situations where A1C testing is not reliable, and can provide a more rapid assessment of glycemic changes compared to A1C.
From the Research
Fructosamine Lab Test
- The fructosamine lab test is used to evaluate intermediate-to-short term glycemic control in patients with diabetes 2.
- It reflects very recent (2 to 3 weeks) glycemic control and can be assayed more rapidly than glycohemoglobin (glycoHb) 2.
- The test measures the level of fructosamine in the blood, which is a compound that forms when glucose binds to proteins in the blood 3.
- Fructosamine levels have been shown to correlate with average blood glucose levels, making it a useful proxy for assessing metabolic control in patients with diabetes 3.
Clinical Usefulness
- The fructosamine test may be a useful adjunctive test for management of outpatients with diabetes in situations where it is not practical to obtain same-day glycoHb concentrations 2.
- It can also be useful for patients who are less compliant with home glucose monitoring or where recent changes in insulin dose or clinical presentation may not be reflected in glycoHb levels 2.
- However, the test has not been evaluated sufficiently to allow its routine clinical use, and its results should be interpreted with caution 4.
- Other indices of glucose homeostasis, such as glycated albumin, may be more useful than fructosamine in certain clinical settings 5.
Limitations
- The fructosamine test is not a replacement for traditional measures of glycemic control, such as glycoHb or plasma glucose 2.
- The test has limitations, including the potential for preanalytical variables to affect results and the lack of standardization in measurement methods 5.
- Further studies are needed to establish the clinical usefulness of fructosamine and to determine its role in the diagnosis and management of diabetes 3, 5.