Liver stiffness assessed by transient elastography as a potential indicator of chronic kidney disease in patients with nonalcoholic fatty liver disease.

backgroundThis study was designed to determine the diagnostic value of liver stiffness measured by transient elastography (TE) in identifying chronic kidney disease (CKD) in individuals with ultrasonography-diagnosed NAFLD.

methodsA total of 1439 adult patients with ultrasonography-diagnosed NAFLD between October 2015 and August 2017 in China-Japan union hospital of Jilin university were initially eligible. According to the exclusion criteria, 24 patients were excluded, and eventually, a total of 1415 patients were included in the study. The AST/ALT ratio and FIB-4 score were calculated from blood tests, and liver stiffness was measured using TE.

resultsThe liver stiffness measured by TE, FIB-4 score, ALT/AST ratio were significantly elevated in CKD patients, compared with those without CKD (P < 0.001). The areas under the curve (AUROC) of liver stiffness, FIB-4 score and AST/ALT ratio were 0.694 (0.670-0.718), 0.707 (0.682-0.730), 0.712 (0.688-0.736), showing no statistically significant difference between these three tests. Further, multivariate analysis identified four independent risk factors for CKD: age, diabetes mellitus, serum uric acid, and liver stiffness. Also, the performance of these four independent variables taken together in a logistic regression model for identifying CKD was 0.834 (AUROC; 95%CI: 0.814-0.853), showing a higher diagnostic performance than that of a single application of liver stiffness.

conclusionsLiver stiffness assessed by TE is a potential indicator for CKD in ultrasonography-diagnosed NAFLD patients. Further, a four-variable model (liver stiffness, age, serum uric acid, and diabetes mellitus) could be a useful tool for identifying subjects at high risk for CKD in NAFLD patients.