A comparative study of three methods of glycosylated haemoglobin measurements

This report summarizes our experience with 3 methods of glycosylated haemoglobin (HbA1) determinations. Glycosylated haemoglobin levels were determined using microcolumn chromatography (Boehringer Mannheim), agar gel electrophoresis (Corning GlytracTM) and colorimetry. The HbA1 values for 40 normal controls using chromatography, electrophoresis and colorimetry were 7.31 +/- 0.67 (+/- 1 S.D.), 7.98 +/- 0.81 and 8.54 +/- 1.09% respectively. The intra-assay coefficients of variation were 3.3, 4.5 and 2.0% respectively. There were also good correlations among the 3 methods of HbA1 measurements: electrophoresis vs chromatography, r = 0.91 (p less than 0.001) and electrophoresis vs colorimetry, r = 0.84 (p less than 0.001). Similarly, all 3 methods correlated well with the fasting and mean grouped blood glucose values (p less than 0.001). The chromatographic method is precise and well suited for small sample analysis. The colorimetric method, although the least expensive is labour intensive, suitable only for large batch analysis and in situations where results are not required immediately. The electrophoresis method is also precise, the least labour intensive and well suited for small and large volume laboratories. This study showed that since all 3 methods demonstrated similar precision and good correlation with fasting and grouped blood glucose values, the method of choice will depend on the requirements and support facilities of the individual laboratories.