A new colorimetric method based on the phenol-sulfuric acid reaction is described for the estimation of serum glycated proteins by the differential reduction of free glucose and hexose bound nonenzymatically with 2.0 and 20 mg of NaBH4 in 0.02 ml of serum, respectively, at room temperature for 15 min. The values (μg hexose/mg protein) in control subjects (n = 60) and diabetics (n = 90) were estimated to be 5.60 ± 0.85 and 10.8 ± 1.6, respectively. The increase was highly significant (P < 0.001) in diabetics. The serum glycated protein levels correlate well with fasting blood sugar values (r = 0.77, P < 0.001, n = 25). There was also a highly significant correlation between glycated protein level and glycated albumin value in individual serum samples (r = 0.85, P < 0.001, n = 25). Values of borohydride reducible glyco-groups bound to serum proteins also correlated well with serum glycated protein levels (r = 0.96, p < 0.001, n = 20) determined by the thiobarbituric acid assay method. The method is found to be simple and rapid, with a coefficient of variations of ±3.8%.
All Science Journal Classification (ASJC) codes
- Endocrinology, Diabetes and Metabolism