NON-INVASIVE TESTS USED TO PREDICT ADVANCED FIBROSIS IN NON-ALCOHOLIC FATTY LIVER DISEASE PERFORM DIFFERENTLY AMONGST PATIENTS OF DIFFERENT ETHNICITIES

Background: Current non-invasive tests (NITs) utilized to screen and predict liver fibrosis were developed in predominantly Caucasian populations, and their performance in non-Caucasians is not well known. The purpose of this study is to evaluate the performance of NITs compared to Transient Elastography (TE) across different ethnic groups from a large diverse national dataset.

Methods: Data were derived from the National Health and Nutrition Examination Surveys (NHANES) 2017-2020, which included a total of 7,767 adults with valid TE measurements. Participants with excessive alcohol consumption, alternative etiologies of liver disease, and/or steatogenic medications were excluded. Patients of multiracial origin or without ethnic information were also excluded. Liver stiffness measurements ≥12 kPa were used to define presence of advanced fibrosis. Performance of the Fibrosis-4 (FIB-4) Index, NAFLD Fibrosis Score (NFS) and the AST to Platelet Ratio Index (APRI) were assessed by calculating the area under the receiver operator characteristic curves (AUROC).

Results: A total of 6,294 adults were included. Participant demographics are shown in Table 1. The prevalence of advanced fibrosis was 3.0% in the overall population based on TE. Prevalence of advanced fibrosis was higher in Caucasian and Mexican-American participants compared to non-Hispanic Black and Asian participants (3.9% vs. 3.5% vs. 2.1% vs. 1.7%, respectively, p=0.003). The FIB-4 and APRI performed significantly worse in non-Hispanic Blacks compared to other ethnicities (Table 2). FIB-4 performed significantly better in Mexican-American and Asian participants and APRI had the highest AUROC among Asian participants. The NFS performed similarly across all ethnicities (Table 2) but tended to overestimate fibrosis in all groups compared to TE. Further analysis revealed that among participants with advanced fibrosis, non-Hispanic Black participants had significantly lower plasma AST and ALT compared to all other ethnic groups. No differences were observed in age, platelets, or albumin in non-Hispanic Black participants with advanced fibrosis compared to other ethnic groups.

Discussion: In a large diverse national dataset, the performance of laboratory based NITs compared to TE showed significant differences across ethnic groups, with significant worse performance in non-Hispanic Blacks. Our findings suggest this may be related to non-Hispanic Blacks with advanced fibrosis having lower AST and ALT levels compared to other ethnic groups. Given that NITs are now widely recommended for use in screening patients for advanced fibrosis, it is imperative that the scores are equitable across ethnic groups. Prospective studies to validate these findings against liver biopsy are warranted.