Evaluation of Fructosamine and Fructosamine-Albumin Ratio in Reflecting Fasting Glucose in Type 2 Diabetic Patients with Chronic Kidney Disease: A Case-Control Study

Abstract

Background Glycated haemoglobin (HbA1c) may not correctly reflect chronic glycaemic control in type 2 diabetes mellitus (T2DM) patients with chronic renal disease (CKD) due to anaemia. Growing evidence reports that fructosamine in reflecting glycaemic control is unaffected by anaemia in in these patients. However, the role of fructosamine remains unclear. Thus, this study aimed to evaluate the acceptance of HbA1c and determine whether fructosamine levels or fructosamine-albumin ratios might be promising biomarkers of glycaemic control in T2DM patients with or without CKD. Methods HbA1c and fructosamine levels were measured in 50 T2DM patients with CKD and 50 T2DM patients without CKD, together with 30 healthy subjects. The area under the curve and receiver operating characteristic curves were used to compare HbA1c, fructosamine levels, and fructosamine-albumin ratio in reflecting glycaemic control. Youden’s index was applied to identify the cut-off points for those parameters. The cut-off point for HbA1c was 6.0%, which was used as the standard method to determine the values of fructosamine and fructosamine-albumin ratio predictors for complications. Results HbA1c levels correlated strongly with fasting blood glucose in T2DM patients without CKD (r = 0.758, p < 0.01) and moderately (r = 0.575, p < 0.01) in those with CKD. However, fructosamine levels and the fructosamine-albumin ratios showed a moderate correlation with fasting blood glucose in those without CKD (r = 0.466, p < 0.01 and r = 0.436, p < 0.01, respectively). Estimated blood glucose levels calculated by HbA1c were similar to actual fasting blood glucose in T2DM patients with different levels of eGFR. However, for fructosamine levels and fructosamine-albumin ratios, the estimated blood glucose levels were similar to actual fasting blood glucose in groups of T2DM patients with eGFR levels lower than 45 and 30 mL/min/1.73 m2, respectively. The fructosamine-albumin ratio was a strong predictor of glycaemic control in T2DM patients with CKD (AUC = 0.923), comparable with HbA1c (AUC = 0.966). A fructosamine level of 270 µmol/L was identified as the optimal cut-off point for monitoring the response to T2DM treatment. Conclusion The fructosamine concentration or fructosamine-albumin ratio effectively reflected blood glucose levels in T2DM Vietnamese patients with CKD (eGFR levels lower than 45 and 30 mL/min/1.73 m2, respectively).