Increased fructose-lysine of hair protein in diabetic patients.

Fructose-lysine, which is formed by binding glucose to lysine, is changed by acid hydrolysis into furosine. Furosine derived from fructose-lysine of hair was determined by high-performance liquid chromatography according to the method of Schleicher et al. Furosine values were significantly higher in diabetic patients than in healthy subjects, and significantly correlated with the stable components of hemoglobin A1 (HbA1) values. These results suggest that furosine, like HbA1, may become an indicator of past blood glucose control at any time in diabetic patients and be useful in investigating diabetic complications on the level of tissue.