An analysis of urinary factors for predicting acute kidney injury in patients with liver cirrhosis

Objective To investigate the predictive factors for acute kidney injury ( AKI) in patients with liver cirrhosis. Methods A total of 105 patients with decompensated liver cirrhosis who visited Beijing YouAn Hospital from May 2017 to April 2018 were enrolled. These patients were divided into AKI group ( n = 49) and non-AKI group ( n = 56) . Their general information and laboratory results were collected, and urine samples were collected on admission to measure urinary angiotensinogen ( AGT) , urinary neutrophil gelatinase-associated lipocalin ( NGAL) , and urinary kidney injury molecule-1 ( KIM-1) , which were corrected for urinary creatinine ( UCr) . The t test was used for comparison of normally distributed continuous data between groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data; the chi-square test was used for comparison of categorical data between groups. A multivariate logistic regression analysis was performed. The receiver operating characteristic ( ROC) curve was plotted to evaluate predictive efficiency. Results Compared with the non-AKI group, the AKI group had significantly higher proportions of patients with upper gastrointestinal bleeding and spontaneous bacterial peritonitis ( χ2= 11. 420 and 8. 083, both P < 0. 05) , significantly higher levels of leukocyte count, total bilirubin, direct bilirubin, urea nitrogen, and serum creatinine ( SCr) ( Z =-3. 401, -2. 082, -2. 207, -5. 872, and-7. 460, all P < 0. 05) , and a significantly lower level of blood sodium ( t =-4. 905, P < 0. 05) . The AKI group had significantly higher urinary NGAL/UCr and urinary KIM-1/UCr than the non-AKI group ( Z =-7. 654 and-2. 395, both P < 0. 05) . The multivariate analysis showed that SCr, blood sodium, and urinary NGAL/UCr were independent predictive factors for AKI in patients with liver cirrhosis ( all P < 0. 05) . The ROC curve analysis showed that at the cut-off value of 88. 1 μmol/L, SCr had a sensitivity of 93%, a specificity of 82%, and an area under the ROC curve ( AUC) of 0. 915 ( 95% confidence interval [CI]: 0. 850-0. 980) in predicting AKI; at the cut-off value of 1. 62 μg/g, urinary NGAL had a sensitivity of 87%, a specificity of 81%, and an AUC of 0. 950 ( 95% CI: 0. 911-0. 989) in predicting AKI; urinary NGAL combined with SCr had an AUC of 0. 964 ( 95% CI: 0. 931-0. 998) . Conclusion Urinary NGAL is an independent risk factor for AKI in patients with liver cirrhosis and can be used for the early diagnosis of AKI in these patients. Urinary AGT and KIM-1 cannot independently predict the development of AKI in liver cirrhosis, and their application value awaits further exploration.