Fructosamine measurement is unreliable in hypoalbuminemia when albumin is at or below what level (in g/dL)?

• A. 2 g/dL or lower
• B. 3 g/dL or lower
• C. 4 g/dL or lower
• D. 5 g/dL or lower

Answer: (B)

Fructosamine testing relies on measuring glycated serum proteins, with albumin providing the major portion of the signal. Under normal conditions, this gives a useful short-term glimpse of average glucose over roughly the past 2–3 weeks. When albumin falls to about 3 g/dL or lower, the amount of glycated albumin becomes too small for the assay to be reliable, and the result can be distorted by the varying contributions of other, less abundant proteins that have different turnover and glycation rates. In short, below 3 g/dL of albumin, fructosamine measurements lose reliability for estimating glycemic control.