Short-term variations in glucose levels have a large impact on inflammatory cytokine levels, cause oxidative stress, and impair host defence against infection.
Fructosamine reflects the level of glycated serum proteins (mostly albumin) with a half-life of two to three weeks, thus representing a shorter period of preceding blood glucose levels, and a quicker response to treatment compared with HbA1c. It reflects rapid fluctuations of glucose and short-term spikes in glucose levels, thereby providing an early indication of poor glucose control.
These authors used a prospective multi-institutional study to assess the utility of fructosamine compared with glycated haemoglobin (HbA1c) in predicting early complications following TKA, and to determine the threshold above which the risk of complications increased markedly.
Patients (both diabetics and non-diabetics) were assessed using fructosamine and HbA1c levels within 30 days of surgery. Complications were assessed for 12 weeks from surgery and included prosthetic joint infection (PJI), wound complication, re-admission, re-operation, and death.
1119 patients (441 men, 678 women) were included in the study. A fructosamine level of 293 μmol/l was identified as the optimal cut-off associated with complications. Patients with high fructosamine (> 293 μmol/l) were 11.2 times more likely to develop PJI compared with patients with low fructosamine (p = 0.001). Re-admission and re-operation rates were 4.2 and 4.5 times higher in patients with fructosamine above the threshold (p = 0.005 and p = 0.019, respectively). These complications remained statistically significant in multiple regression analysis.
The incidence of each type of complication in patients with fructosamine < 293 μmol/l (high; n = 1059) compared with patients with fructosamine ≥ 293 μmol/l (low; n = 60) is shown in the chart below.
Unlike fructosamine, all three cut-offs for HbA1c failed to show a significant association with complications.
