Urinary kidney injury molecule-1 as an early indicator to predict contrast-induced acute kidney injury in patients with diabetes mellitus undergoing percutaneous coronary intervention.

With the improvement of the skill level of coronary intervention, contrast agents are used more widely. As a result, contrast-induced acute kidney injury (CI-AKI) is currently the third leading cause of hospital-acquired AKI. Traditionally, AKI is defined by measuring an increase of the serum creatinine concentration (Scr). CI-AKI indicates impairment in renal function, which is diagnosed as an elevation in the SCr levels following intravascular injection of the contrast media. However, Scr is an insensitive indicator for detecting CI-AKI. The present study was designed to investigate whether human urinary kidney injury molecule-1 (KIM-1) is an early marker to predict CI-AKI in patients with diabetes mellitus undergoing percutaneous coronary intervention (PCI). The present study includes the general clinical data of 145 patients with diabetes mellitus who underwent PCI between March 1, 2013 and December 31, 2013. A non-ionic, low osmolarity contrast agent was used during the present study. The Scr levels and estimated glomerular filtration rate were measured prior to and within 24 and 48 h after the injection of contrast agents. Urinary samples were collected prior to and within 2, 6, 12, 24 and 48 h after the coronary interventional procedure. Simultaneously, the urinary KIM-1 values were measured using an ELISA kit. CI-AKI was diagnosed as an increase of ≥0.5 mg/dl or ≥25% in Scr concentration over baseline, 24-48 h after the procedure. In total, 19 of 145 (13.1%) patients exhibited CI-AKI. There was a significant difference (P<0.05) between the urinary KIM-1 levels measured 2, 6, 12, 24 and 48 h after the procedure and those prior to the procedure in the CI-AKI group. There was no significant difference between the Scr values measured 24 h after the procedure and those prior to the procedure. Evidently, using KIM-1 values to predict CI-AKI was <24 h earlier compared to using Scr values. The area under the receiver operating characteristic curve of KIM-1 24 h after the procedure was 0.856 and the 95% confidence interval of the corresponding area was 0.782-0.929. When the pivotal point of CI-AKI diagnosis was 6,327.755 pg/ml, the specificity was 85.7% and the sensitivity was 73.7%. Univariate analysis showed that the Scr concentration was positively correlated with the urinary KIM-1 level during the time prior to the procedure and 24 and 48 h after the procedure. In conclusion, the urinary KIM-1 may be a potential indicator for the early diagnosis of CI-AKI.