Evaluation of urinary haptoglobin level as a biomarker of diabetic nephropathy in children with type 1 diabetes.

Abstract

Type 1 diabetes mellitus (T1DM) is a common endocrine disease in children. Early recognition of complications of T1DM is important for preventing long-term morbidity and mortality. We aimed to investigate whether urinary haptoglobin level is a biomarker of diabetic nephropathy in children with T1DM. Ninety T1DM patients, aged between 2-18years, and 60 healthy age-matched children were included in the study. Glycosylated hemoglobin (HbA1c), spot urine creatinine, microalbumin, protein and haptoglobin levels of all cases were measured and compared. Correlations between HbA1c level, duration of diabetes, spot urine microalbumin/creatinine (uACR), protein/creatinine (uPCR), and haptoglobin/creatinine (uHCR) ratios in the T1DM group were evaluated. T1DM and control groups were homogeneous in terms of age, sex, and anthropometric measurements. uACR was higher in the T1DM group than in the control group (14mg/g vs. 6mg/g) while uHCR was not elevated in T1DM patients. Nevertheless, uHCR was higher in the microalbuminuria group when compared to the normoalbuminuria group. In the T1DM group, moderate positive correlations between uPCR with uACR and uHCR, and weak correlation between uACR and uHCR were found (r = 0.60, p < 0.001; r = 0.55, p < 0.001; r = 0.24, p = 0.03, respectively). No significant relationship was found between diabetes duration, HbA1c levels and uACR, uPCR, and uHCR. Although uHCR in the T1DM group was similar to the control group, uHCR was higher in the microalbuminuria group than in the normoalbuminuria group. These results show that the uHg level could be a biomarker of diabetic nephropathy, but not earlier than albuminuria in the disease course. A higher resolution version of the Graphical abstract is available as Supplementary information.