抄録
For the determination of glycosylated hemoglobin, we studied a spectrophotometric “Automated-procedure” by using phytic acid. Then, the above procedure was compared with an isoelectric focusing method, a mini-column method and an electrophoretic method.
As anti-coagulants in this procedure, EDTA-2Na and EDTA-2K were used for the determination of hemoglobin A1 concentration but not heparin sodium salt, sodium fluoride, sodium citrate nor potassium oxalate. Variations of intra-assay were good (CV=1.96-2.68%). Variations of inter assay were suitable (CV=5.34-6.34%). The correlation between phytic acid method and the other three methods were shown on the following lines (a, b, c),
(a) isoelectric focusing method (r=0.934, y=1.07X+1.32),
(b) mini-column method (r=0.918, y=1.00X+0.29),
(c) electrophoretic method (r=0.970, y=0.87X-0.41).
Comparison of glycosylated hemoglobin values in normal subjects and diabetics were reviewed as follows;
(a) isolelectric focusing method: normal subjects: 5.04±0.75%HbA1C (mean±SD), n=34 diabetics: 8.81±2.37%HbA1C, n=53
(b) mini-column method: normal subjects: 6.54±0.93%HbA1, n=89 diabetics: 10.28±2.52%HbA1, n=160
(c) electrophoretic method: normal subjects: 7.33±0.80%HbA1, n=37 diabetics: 12.24±3.49%HbA1, n=36
(d) phytic acid method: normal subjects: 6.37±1.03%HbA1, n=74 diabetics: 10.76±2.58%HbA1, n=160 (“n” indicates the number of subjects)
The concentrations of glycosylated hemoglobin (HbA1) by phytic acid method were compared in well controlled, moderately controlled and poorly controlled diabetics. The significant differences (p<0.001) were observed between the poorly controlled (12.26±2.09%) and moderately controlled diabetics (9.69±1.90%) or poorly controlled and well controlled diabetics (9.02±1.65%).
The above findings suggest that this “phytic acid method” is suitable for the routine use of the determination of hemoglobin A1 values in clinical laboratories.