Fructosamine is a glycated protein that reflects average blood glucose levels over a 2-3 week period, providing a shorter-term assessment of diabetic control than hemoglobin A1c. This test measures the amount of glucose that has attached to serum proteins, primarily albumin, through a non-enzymatic process called glycation. Fructosamine levels are particularly valuable for monitoring diabetic control in patients with abnormal hemoglobins (such as sickle cell disease or thalassemia) where A1c testing may be unreliable. It's also useful for evaluating recent changes in diabetes management, monitoring pregnant women with diabetes, and assessing control in children with type 1 diabetes. The test provides a more immediate picture of glycemic control and can help guide treatment adjustments more quickly than A1c testing.