Technical and clinical evaluation of fructosamine determination in serum

We evaluated a serum fructosamine (glycated serum proteins) assay for efficacy in the diagnosis and follow-up of diabetic patients. A Roche reagent kit, based on nitroblue tetrazolium reduction in alkaline medium, was used in COBAS FARA centrifugal analyzer. We demonstrated that this method is precise, linear and unaffected by serum hemolysis. However, bilirubin affected the test positively and lipemia negatively. Fructosamine (F) correlated positively with total protein (P) (r = 0.809) and albumin (r = 0.746) in a group of 48 non-diabetic individuals. A good correlation was observed between F and glycated hemoglobin from the sera of 514 patients (r = 0.794). A better correlation (r = 0.838) was obtained when F was corrected for P concentration (F/P). Different F and F/P means were calculated only in patients with overt diabetes, compared to normals. Gestational diabetes was associated with a highly significant F increase. However, its low sensitivity (21%) precludes the use of F as an effective screening test for that condition. Nevertheless, because of its simplicity, low cost and rapidity in reflecting changes in the metabolic control of diabetes, F should be considered a valuable test to assess glycemic control in diabetic patients.