Diagnostic Value of Non-invasive Liver Function Tests in Liver Fibrosis and Changes in These Parameters Post-metabolic Surgery

Purpose This study aimed to ascertain the diagnostic accuracy of non-invasive liver function tests in liver fibrosis and assess their changes after metabolic surgery. Materials and Methods 1005 individuals with severe obesity who were referred for metabolic surgery were analysed. All participants had blood samples taken for liver enzymes and lipid profile. In addition, hepatic indexes, including AAR, APRI, NFS and Fibrosis-4 (FIB4), were checked. Furthermore, all participants underwent two-dimensional shear wave elastography (2D-SWE). All investigations were repeated 6–8 months after metabolic surgery. The receiver operating characteristic (ROC) curve and the area under the ROC curve was utilised to determine the optimal cut-off values for baseline study parameters. Logistic regression was applied to predict the relationship between study parameters—as predictors—and change in 2D-SWE. Results AST/ALT (AAR) was the most sensitive (79%) pre-operative non-invasive serological marker for detecting liver fibrosis, whereas NAFLD Fibrosis Score (NFS) was the most specific (84%). AST/upper limit of the normal AST range × 100/platelets (× 10 9 /L) (APRI) showed a positive correlation with 2D-SWE post-metabolic surgery ( p -value = 0.021). Regression analysis from both adjusted and unadjusted models showed that baseline AAR was a predictor of postoperative liver status in terms of hepatic fibrosis. Conclusion AAR has a high sensitivity, whereas NFS exhibits a high specificity in diagnosing liver fibrosis. The authors recommend using both investigations in conjunction with 2D-SWE to increase the likelihood of detecting liver fibrosis. Graphical Abstract