CHROMATOGRAPHIC AND COLORIMETRIC DETECTION OF GLYCOSYLATED HEMOGLOBINS - COMPARATIVE ANALYSIS OF 2 DIFFERENT METHODS

The measurement of glycosylated hemoglobins in diabetic patients represents a new approach to the problem of the long-term glycemie control. Chromatographic procedures are usually employed to separate the glycosylated components of hemoglobin; we performed a comparative analysis of two different methods: Chromatographic and colorimetric. Chromatographic separation on small ion-exchange resin columns gives high precision (coefficient of variation = 1.7%) over the whole range of normal and diabetic values of percentage of glycosylated hemoglobin (3.2-15.9%). An alternative technique is the measurement of 5-hydroxymethylfurfural released by oxalic acid hydrolysis of the hexoses bound to hemoglobin, as proposed by Fluckiger and Winterhalter (Fluckiger, R. and Winterhalter, K.H. (1976) FEES Lett. 71, 356-360). Normal values, expressed as 5-hydroxymethylfurfural absorbance per 10 g of total hemoglobin, range from 133 to 235, with mean ± S.D. = 189 ± 26; while diabetic patients show a range from 220 to 443 and mean ± S.D. = 318 ± 65. This last method gives satisfactory precision over the entire range of values examined (coefficient of variation = 4.2%) and has proved simple and inexpensive. The correlation between the two methods is very high (n = 20; r = 0.98; p < 0.001) with a regression line, y = 25. Ix + 40.3. The storage of the hemolysates at -20°C for up to 70 days for the colorimetric method and up to 260 for the Chromatographic procedure does not decrease the precision of either technique. © 1979.