Glycosylated hemoglobins and glycosylated plasma proteins in the diagnosis of diabetes mellitus and impaired glucose tolerance.

Total and stable glycosylated hemoglobins and glycosylated plasma proteins were determined on 53 patients referred for a glucose tolerance test. Significant correlations were found with fasting blood glucose (r greater than 0.89), 2-h glucose (r greater than 0.69), and area under the glucose tolerance curve (r greater than 0.75), but the correlations with labile glycosylated proteins were not significant. Thirty-one of the patients were normal, five had impaired glucose tolerance (IGT), and seventeen diabetes mellitus (DM) according to the WHO criteria. Comparison of the glycosylated protein values showed that, in all cases, the values for those with IGT and DM were significantly (P less than 0.001) greater than the values for normals. The range of values of stable glycosylated hemoglobins for those with DM (9.4-24.4%), those with IGT (8.6-10.0%), and normals (5.0-8.5%) shows that there was no overlap between overt diabetic subjects and normal subjects. This was also found for total glycosylated hemoglobins. The results for glycosylated plasma proteins, total and stable, were comparable, but one patient with overt DM and two with IGT had values within the normal range. The measurement of glycosylated hemoglobins and glycosylated plasma proteins by the simple, precise, affinity-chromatography method is potentially a quick, accurate, and simple screening test for patients with DM and IGT and deserves consideration as criteria for their diagnosis.