Fructosamine is a glycated serum protein which is formed by the combination of glucose and protein in the blood. Higher the levels of blood glucose, higher will be the concentration of fructosamine. Hence, the blood fructosamine levels reflect the amount of glucose present. Glycation mainly involves albumin which is the principal blood protein. Other protein substance may also combine with glucose. These protein substances have a lifespan of about 2-3 weeks. By measuring the level of fructosamine, you get an idea of the level of blood glucose over the past 2-3 weeks. Fructosamine test is usually performed on a blood sample to measure the level of fructosamine in blood. The test is performed to confirm Diabetes and also useful in estimating the blood sugar trends in the diabetic patient.