Use of fructosamine test in diabetic children

OBJECTIVE: The goal of this study was to assess the effect of glucose and the contribution of the aldimine component on the measurement of fructosamine, the relationship of serum fructosamine with glycosylated plasma proteins, as measured by a new high-performance liquid chromatography methodology (Glyc PP-HPLC) and by an affinity chromatography (Glyc PP), and the ability of serum fructosamine to assess acute, short-term (1-2 wk), and long-term (2-3 mo) glycemic control. RESEARCH DESIGN AND METHODS: The measurement of fructosamine was unaltered by the addition of up to 27.5 mM glucose or by the elimination of the aldimine component of serum specimens by dialysis. Fructosamine was generated in vitro by incubating serum aliquots. This generation was dependent on time, glucose concentration, and temperature. RESULTS: Fructosamine (n = 27) correlated well with Glyc PP (r = 0.76, P less than 0.01) and significantly less with Glyc PP-HPLC (r = 0.46, P less than 0.01). Although oral glucose ingestion increased serum glucose acutely by 200%, fructosamine was unchanged at each time interval. Improving glycemic control decreased the mean serum fructosamine concentration from 3.68 (baseline) to 3.28 mM (P less than 0.01) at 1 wk and to 3.13 mM (P less than 0.01) at 2 wk. HbA1c correlated with fructosamine (r = 0.59) and Glyc PP-HPLC (r = 0.47) but correlated best with Glyc PP (r = 0.83). CONCLUSIONS: These results indicate the fructosamine assay is unaltered by serum glucose, solely measures the ketoamine component, correlates well with glycosylated plasma proteins measured by aminophenylboronic acid column chromatography, is unaffected by acute changes of serum glucose, and may be used to monitor changes in glycemic control over a 1-wk interval.