Evaluation of urinary kidney injury molecule-1 as an early biomarker for diabetic nephropathy in children and adolescents with type 1 diabetes mellitus

Abstract

Type 1 diabetes mellitus (T1DM) is a chronic disorder associated with significant microvascular complications, including diabetic nephropathy (DN), in children and adolescents. Early detection of renal involvement is essential, as traditional markers may not reliably identify early disease. This study aimed to evaluate urinary kidney injury molecule-1 (KIM-1) as an early marker of DN in paediatric patients with T1DM. This cross-sectional study enrolled 60 children with T1DM, who were categorized into three equal groups: a normoalbuminuria group (n = 20), a microalbuminuria group (n = 20), and a macroalbuminuria group (n = 20). All participants underwent detailed history taking, comprehensive clinical examination, and laboratory investigations, including serum urea and creatinine, glycated hemoglobin (HbA1c), and measurement of the urine albumin-to-creatinine ratio (UACR) in early-morning samples to assess albuminuria. Urinary KIM-1 was quantified using a sandwich enzyme immunoassay technique (Elabscience Biotechnology Co., Ltd., USA) according to the manufacturer’s instructions. Children with microalbuminuria and macroalbuminuria had markedly elevated urinary KIM-1/urinary creatinine ratios compared with the normoalbuminuria group. Receiver operating characteristic (ROC) curve analysis showed that the urinary KIM-1/urinary creatinine ratio had excellent discriminatory ability for differentiating macroalbuminuria from normoalbuminuria, with an area under the curve (AUC) of 0.90 and an optimal cut-off value of ≥ 0.2, yielding 90% sensitivity and 80% specificity. For the detection of microalbuminuria, the urinary KIM-1/urinary creatinine ratio showed fair discriminatory ability, with an AUC of 0.70 and an optimal cut-off value of ≥ 0.1, providing 90% sensitivity and 65% specificity. Urinary KIM-1 and the urinary KIM-1/urinary creatinine ratio may serve as noninvasive early biomarkers of DN in children and adolescents with type 1 diabetes. Future prospective cohort studies are needed to establish their diagnostic validity.