Assay of glycated fibrinogen in plasma as an indicator of blood glucose control

A method of assay for glycated fibrinogen (C-Fbg) in plasma has been developed. This method is based on the measurement of 1-deoxy-1-morpholino-D-fructose (DMF) in the fibrinogen (Fbg) solution separated from plasma and redissolved. Twenty five NIH units of thrombin was added to 600 microliters of plasma. After incubation, the fibrin clot was separated and washed. The fibrin clot was redissolved with Owren's veronal buffer contained urokinase. After incubation, DMF was measured using a Fructosamine Kit. G-Fbg measured by this method correlated significantly with the amount of furosine that was a specific product by hydrolysis of glycated lysine residue. In this method, the CV for intraday assay ranged from 2.0 to 3.6% and that for interday assay was 3.9%. The average of G-Fbg values in 78 diabetic patients (23.8 +/- 10.7 mumol DMF/g Fbg) was significantly higher than in 26 normal subjects (9.2 +/- 3.8 mumol DMF/g Fbg). The G-Fbg value correlated with blood glucose at the same time or one day earlier than 1-2 weeks or 1 month earlier. These results suggest that assay of G-Fbg by this method may be useful in monitoring short-term control of blood glucose in diabetic patients.