Basic Performance of an Enzymatic Method for Glycated Albumin and Reference Range Determination

Background:Glycated albumin (GA) is a medium-term glycemic control marker of diabetes and may be more sensitive to changes in plasma glucose than hemoglobin A1c. We studied where and how many fructosyl groups bind to albumin, and which glycation sites are measured by the enzymatic method for GA. We also studied the basic performance of the enzymatic method for GA.Methods:Glycated albumin was measured using an enzymatic method (Lucica®GA-L, Asahi Kasei Pharma) on a biochemical autoanalyzer. Molecular weights of purified GA and nonglycated albumin were measured by a mass spectrometry system. Two hundred one healthy volunteers with normal results of oral glucose tolerance testing were recruited to determine the reference range in Americans.Results:The present method measured only glycated amino acids from albumin in serum protein. We estimate that the number of glycated amino acids measured by this method was approximately two per molecule of albumin. The general performance (sensitivity, specificity, reprod...