Plasma Protein GlycationAs Measured by

The fructosamine test for assessing control of glucose in bloodhas been extensively evaluated, but some questions remain regarding its validity. From the analytical and clinical evaluation we present here, we conclude that: (a) the test is sensitive to variations in the composition of the sample protein; (b) the fructosamine reaction isalmost completely unaffectedby labilefractions;(C) the concentrationsof fructo-samine correlate well with the degree of glycationof total serum proteins, especially with glycated albumins and glycat-ed immunoglobulins, as determined by affinity chromatogra-phy; ( the correlation with glycated hemoglobin (Hb A,), measured as the stable fraction, is very poor, in diabetics treated with insulin (r = 0.373), or with oral hypoglycemic agents (r = 0.390); and (e) fructosamineand Hb A1 are, in fact, expressionsof differentperiodsof metaboliccontrolan