Indole Lactic Acid in Plasma and Urine: A Potential Biomarker for Chronic Kidney Disease and Inflammatory

Hao Hong,1,&ast; Junyao Zheng,2,&ast; Haimin Shi,2 Suya Zhou,3 Yue Chen,4 Ming Li2 1Intensive Care Unit, the First Affiliated Hospital of Soochow University, Soochow, People’s Republic of China; 2Laboratory Nephrology, the First Affiliated Hospital of Soochow University, Soochow, People’s Republic of China; 3Laboratory Nephrology, Jinshan Hospital of Fudan University, Shanghai, People’s Republic of China; 4Laboratory Nephrology, the First People’s Hospital of Kunshan, Soochow, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Ming Li, Email 1925924373@qq.comPurpose: We aimed to explore changes in plasma and urine indole lactic acid (ILA) levels and the relationship between inflammation and ILA in chronic kidney disease (CKD) patients and healthy people.Patients and Methods: Forty-seven CKD patients and 30 healthy individuals were included in this study. One-way ANOVA was used for variables with normal distribution and homogeneous variance. A rank-sum test was performed for non-normally distributed variables. Correlation analyses were performed using Pearson’s or Spearman correlation analyses. Independent relationship between patients and CKD was analyzed using ordinal and binary logistic regressions. Receiver operating characteristic (ROC) curve was used.Results: Plasma and urine ILA levels were positively correlated (r = 0.51, P < 0.01). Plasma ILA was positively correlated with BMI, age, creatinine, BUN, triglycerides, and uric acid and negatively correlated with hemoglobin levels. Urine ILA levels were positively correlated with age, creatinine, BUN, and uric acid and negatively correlated with hemoglobin and albumin levels. Ordered logistic regression analysis showed that CKD was significantly correlated with plasma ILA (OR=4.49, P