[Diagnosis of the diabetic metabolic status using fructosamine (and HbA1c) determination. The glycation quotient Glyc-Q, the glycation nomogram]

Abstract

The determination of fructosamine in serum is an accepted tool for the metabolic monitoring of diabetic patients. It provides an estimation of the glycemia state during the preceding 10 to 20 days. The turn-over of serum proteins is in general faster than that of hemoglobin. Therefore, fructosamine is faster responding than HbA1c to recompensation or fluctuations in glycemic control as observed in labile metabolic situations. On the other hand, under conditions of stable metabolic control fructosamine values correlate closely to HbA1c. The relation between the two parameters can be visualized in a nomogram of HbA1c, fructosamine and glucose or be expressed by a quotient (Glyc-Q = Fructosamine*2.2/HbA1c). A deviation from the stable metabolic situation (Glyc-Q = 100) reflects a trend in the recent development of glycemia: a Glyc-Q of greater than 120 is obtained in the state of decompensation, whereas in recompensation the Glyc-Q decreases significantly to values below 80. We propose to use the Glyc-Q in situations where a fast assessment of the glycemic state or an estimation of the development of glycemia within short intervals of observation are required.