Type 2 Diabetes Diagnosis & Treatment Fructosamine Test for Diabetes: Pros, Cons, Compared to A1C Understanding Diabetes Blood Tests By Debra Manzella, RN Updated on January 10, 2024 Medically reviewed by Kelly Wood, MD Print Table of Contents View All Table of Contents Purpose Benefits Limitations How It's Done Normal Range Other Considerations FAQs The fructosamine and A1C tests for diabetes both measure blood sugar. But there are differences, with the fructosamine test measuring average blood glucose levels across two or three weeks prior to the test date and the hemoglobin A1C test (HbA1c) measuring across two to four months. The shorter fructosamine time window is not sufficient for determining a long-term prognosis. The fructosamine test measures glycated proteins (not glycated hemoglobin) that circulate in the blood for only 14 to 21 days. Measuring these proteins provides a picture of the amount of sugar in your blood for just that time period. While the A1C test is now generally preferred, fructosamine tests are more accurate with certain health conditions and situations. This article explains benefits and limitations of both the fructosamine and A1C tests, and why each may be used. It explains what the results mean and how you can convert the test results from fructosamine to A1C. Verywell / Hugo Lin Purpose of the Fructosamine Test Unlike the A1C test, the fructosamine test is not used as a screening test for people who do not have diabetes or who have well-controlled diabetes. Instead, the fructosamine test may be used in situations in which the A1C test is less reliable or doesn't offer the same information. Benefits of Fructosamine Test The fructosamine test may be more useful in certain situations, like managing diabetes in the short term, or with certain health conditions. For example, it may be used if you've had a recent change in your medicines or insulin, as it can help gauge the effectiveness of the new treatments in a more immediate time window. The test may also be used during pregnancy when your body is changing constantly, which may lead to falsely low A1C results. Health conditions in which the fructosamine test may offer benefits include: Hemolytic anemia or recent blood loss, because the rapid turnover of your red blood cells means a hemoglobin A1C test result will be falsely low Sickle cell anemia Kidney failure (end-stage renal disease) Liver disease HIV infection Recent blood transfusions Fructosamine may be a useful test for people who develop gestational diabetes (diabetes during pregnancy) because changes in red blood cells and rapid blood sugar increases can make A1C results less reliable. Fructosamine, the A1C Test, and Race Use of the fructosamine test may include considerations based on race and ethnicity. The A1C test results show higher levels in Black, Asian, and Hispanic populations when compared with tests in White people, even though their blood sugar levels are the same. The A1C has raised concern over potential misdiagnosis, meaning that additional tests like the fructosamine may be helpful. Drawbacks of Fructosamine Test Some healthcare providers may be moving away from the fructosamine test because of its limitations, including accuracy in assessing long-term complications of diabetes. A 2016 review concluded that the fructosamine test doesn’t have enough evidence to support its use. The authors note that a different test that measures glycated albumin—which also reveals blood sugar levels over the short term—shows promise in most accurately identifying prediabetes in African-Americans and those who are not obese. However, the glycated albumin tests also have limitations. Albumin levels can be affected by other health conditions, including thyroid disease, kidney and liver conditions, or even smoking. Some of these factors also affect fructosamine tests. A 2015 article also noted that glycated albumin testing is considered more reliable than fructosamine testing. How the Fructosamine Test Is Done This is a blood test done with a sample drawn from a vein or fingerstick at your healthcare provider's office and analyzed in a laboratory. It is usually covered by health insurance. Risks are minimal, as with any blood draw, and no special preparation (e.g., fasting) is required. A home-based fructosamine test was discontinued in 2002 because it wasn't accurate. The A1C test also needs to be done using certified and standardized methods. Normal Range for Fructosamine Test It's not entirely clear what fructosamine levels indicate and how they correlate to diabetes or its complications, but the following guide is suggested: For people without diabetes, the fructosamine range should be 175-280 millimoles per liter (mmol/L).For people with controlled diabetes, the fructosamine range should be 210-421 millimoles per liter (mmol/L).For people with uncontrolled diabetes, the fructosamine range should be 268-870 millimoles per liter (mmol/L). High fructosamine levels indicate high average blood glucose levels took place in the previous two to three weeks. Usually, a trend is monitored with repeat testing, whether that is of fructosamine levels or other indicators, such as glycated albumin or HbA1c. If the results remain high, it shows you have not had good blood glucose control. Your healthcare provider will try to determine the cause and help you adjust your medications, diet, and other factors. Reference Ranges for A1C Fructosamine results may be considered alongside the HbA1C and other tests. The reference ranges for A1C results are:No diabetes: below 5.7%Borderline/prediabetes: 5.7% to 6.4%Diabetes: 6.5% or higher Converting Fructosamine to A1C One formula used to convert fructosamine to A1C uses the fructosamine level (the mmol/L) x 0.017 + 1.61 to arrive at the hemoglobin A1C as a percentage. Other mathematical equations also may be used, and the numbers may vary depending on a person's overall health, weight, and lifestyle choices like exercise. Symptoms of Ketoacidosis Type 2 Diabetes Doctor Discussion Guide Get our printable guide for your next healthcare provider's appointment to help you ask the right questions. Download PDF Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Email Address Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. Other Considerations Sometimes, the reliability of the fructosamine test can be compromised. Any condition that affects serum albumin production, either increasing or decreasing turnover, may affect the reliability of the fructosamine test. Some examples of these conditions include: Liver diseases (e.g., cirrhosis) Nephrotic syndrome Thyroid disease Paraproteinemia In addition, high levels of ascorbic acid (vitamin C) can interfere with the reliability of the test. Therefore, patients should abstain from ascorbic acid supplements for a minimum of 24 hours prior to sample collection. The Chinese herb Polygalae Radix may also affect results. A Word From Verywell A fructosamine test is likely to be part of a larger group of tests your healthcare provider orders. Take your time to review your results, and be sure to ask questions about anything you don’t understand. Getting abnormal test results can be worrisome, but remember there are many easy ways you can take control of your blood sugar with diet, medication, and other lifestyle changes, such as exercise. Use your test results as a motivator to learn more about diabetes and make simple changes so you can see improvement the next time you're tested. Frequently Asked Questions How does anemia affect blood glucose levels? Anemia does not affect blood glucose levels (blood sugar). However, the presence of anemia can interfere with blood glucose readings and cause missed readings of hypoglycemia (low blood sugar). In response, a mathematical formula has been created to avoid incorrect glucometer readings. What is mmol/L? Millimoles per liter (mmol/L) is a unit of measurement that shows the amount of a substance in a specified amount of fluid. It is primarily used in countries outside of the United States. In the US, it is more common to record measurements using Mg/dL (milligrams per deciliter). By multiplying the mmol/L measurement by 18, you can convert it to Mg/dL. 12 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. American Diabetes Association. 6. Glycemic targets: Standards of medical care in diabetes—2022. Diabetes Care. 2022;45(Supplement 1):S83–S96. doi:10.2337/dc22-S006 Nansseu JR, Fokom-Domgue J, Noubiap JJ, Balti EV, Sobngwi E, Kengne AP. Fructosamine measurement for diabetes mellitus diagnosis and monitoring: a systematic review and meta-analysis protocol. BMJ Open. 2015;5(5). doi:10.1136/bmjopen-2015-007689 Danese E, Montagnana M, Nouvenne A, Lippi G. Advantages and pitfalls of fructosamine and glycated albumin in the diagnosis and treatment of diabetes. J Diabetes Sci Technol. 2015;9(2):169–176. doi:10.1177/1932296814567227 Mohsin ZA, Paul A, Devendra S. Pitfalls of using HbA1c in the diagnosis and monitoring of diabetes. London Journal of Primary Care. 2015;7(4):66-69. doi:10.1080/17571472.2015.11493437 Welsh KJ, Kirkman MS, Sacks DB. Role of glycated proteins in the diagnosis and management of diabetes: research gaps and future directions. Dia Care. 2016;39(8):1299-1306. doi:10.2337/dc15-2727 Fayyaz B, Rehman HJ, Minn H. Interpretation of hemoglobin A1C in primary care setting. J Community Hosp Intern Med Perspect. 2019 Feb 11;9(1):18-21. doi:10.1080/20009666.2018.1559432. Malmström H, Walldius G, Grill V, Jungner I, Gudbjörnsdottir S, Hammar N. Fructosamine is a useful indicator of hyperglycaemia and glucose control in clinical and epidemiological studies – cross-sectional and longitudinal experience from the amoris cohort. Hribal ML, ed. PLoS ONE. 2014;9(10):e111463. doi:10.1371/journal.pone.0111463 American Diabetes Association Professional Practice Committee. 15. Management of diabetes in pregnancy: Standards of medical care in diabetes—2022. Diabetes Care. 2022;45(Supplement_1):S232-S243. doi:10.2337/dc22-S015 Johns Hopkins Medicine. Alternative markers of glycemia: fructosamine, glycated albumin, 1,5-AG. American Diabetes Association Professional Practice Committee. 2. Classification and diagnosis of diabetes: Standards of medical care in diabetes—2022. Diabetes Care. 2022;45(Supplement_1):S17-S38. doi:10.2337/dc22-S002 Henderson WO, Parker MH, Batch BC. How should you assess glycemic control if the hemoglobin A1c is inaccurate or uninterpretable? Cleve Clin J Med. 2021 Feb 1;88(2):81-85. doi:10.3949/ccjm.88a. American Diabetes Association (ADA). Common Terms. Additional Reading Johns Hopkins Medicine: Johns Hopkins Diabetes Guide. Alternative Markers of Glycemia: Fructosamine, Glycated Albumin, 1,5-AG. By Debra Manzella, RN Debra Manzella, MS, RN, is a corporate clinical educator at Catholic Health System in New York with extensive experience in diabetes care. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit