[A colorimetric method of determining non-enzymatically glycosylated albumin and hemoglobin]

A method for measuring non-enzymatically glycosylated albumin and hemoglobin in a single blood sample is described. It is advisable that these proteins be assayed separately, because albumin metabolism rate is higher than that of hemoglobin and therefore glycosylated hemoglobin may be regarded as a criterion for diagnosing diabetes mellitus and the level of glycosylated albumin as an indicator of diabetes mellitus compensation and a characteristic that permits monitoring the course of treatment. The method consists in preparation of the blood erythrocytic mass and plasma, followed by trichloracetic acid hydrolysis of glycosylated hemoglobin and glycosylated albumin during heating and assay of the resultant fructose forming a colored complex with thiobarbituric acid. Twenty-nine normal subjects were examined with the use of this method; the mean arithmetic (means +/- m) has made up 3.68 +/- 0.21 mumols of fructose glycine per g of hemoglobin for glycosylated hemoglobin and 27.0 +/- 1.78 mumols of fructose glycine per g of albumin for glycosylated albumin. In diabetics these values were several times higher and the mean arithmetic value of glycosylated hemoglobin was 20.5 +/- 0.45 mumols of fructose glycine per g of hemoglobin and that of glycosylated albumin 63.8 +/- 1.7 mumols of fructose glycine per g of albumin (n = 42), the significance of differences being p less than 0.001.