Glycohemoglobin measured by automated affinity HPLC correlates with both short-term and long-term antecedent glycemia.

We evaluated glycohemoglobin (GHb) and glycated plasma protein (GPP) by automated affinity HPLC for their ability to monitor both short-term and long-term antecedent glycemia in 70 diabetic subjects. We placed 30 subjects on an intervention protocol in which insulin and (or) dietary changes were made twice weekly to acutely decrease glycemia. We monitored 40 subjects at 6-week intervals; changes in the clinical regimen were made at that time only. Despite weekly changes in mean blood glucose in the subjects who received more intensive intervention. GHb concentrations correlated significantly with the weekly (r = 0.66, P < 0.001), 2-week (r = 0.70, P < 0.001), 3-week (r = 0.72, P < 0.001), and 6-week (r = 0.83, P < 0.001) mean glucose concentrations. GPP correlated significantly with measured glycated albumin determined by boronate affinity columns (r = 0.83, P < .001) and correlated best with the 1-week (r = 0.66, P < 0.001), 2-week (r = 0.64, P < .001) and 3-week (r = 0.60, P < 0.001) mean antecedent glucose concentration. Thus, GHb, traditionally considered a marker for only long-term diabetic control, correlated significantly with both short-term and long-term antecedent glycemia.

Clinical validation of a second-generation fructosamine assay.

The serum fructosamine assay, used to monitor short-term clinical glycemic control, reportedly has several technical drawbacks. However, technical improvements have resulted in a new second-generation assay of fructosamine. We evaluated this second-generation assay (from Roche Diagnostics) in 529 nondiabetic and diabetic patients and found a highly significant correlation with results of the first-generation assay (r = 0.91, P less than 0.001). Use of the second-generation assay with samples from patients classified on the basis of glycemic control according to their glycohemoglobin (GHb) values, enabled us to discriminate between the nondiabetics, diabetics with "good/moderate" control (i.e., GHb less than 10%), and diabetics with "poor" control (GHb greater than or equal to 10%). We evaluated the validity of the second-generation assay to assess short-term glycemic control in 23 non-insulin-dependent diabetic patients who participated for 10 weeks in an intensive intervention program designed to rapidly normalize the clinical glycemic profile. Results correlated significantly with the one-week average capillary blood glucose concentration (CBG) and with the three-week average CBG in all 23 patients. In addition, the second-generation fructosamine assay results demonstrated a significant decrease at each week of study, as did the average CBG. Results of the first- and second-generation assays correlated significantly at each week of study. GHb correlated significantly with both the second- (r = 0.78, P less than 0.001) and first-generation fructosamine assay results (r = 0.77, P less than 0.001) for the baseline blood samples of the intervention study, but this correlation decreased (to r = 0.35, P = 0.09 and r = 0.34, P = 0.09, respectively) by the conclusion of the study.