Transient Elastography and Serum-based Tests for Diagnosis of Fatty Liver and Advanced Fibrosis in a Community Cohort- a Cross Sectional Analysis

Noninvasive tests (NITs) are necessary for knowing the true prevalence of fatty liver (FL) and advanced fibrosis. NITs for diagnosis of FL and fibrosis were compared.Data were obtained from the National Health and Examination Survey (2017-2018). Participants were excluded with other liver diseases, missing data for NIT calculation, and/or excessive alcohol use. Area under the receiver operating characteristic (AUROC) compared the accuracy of 4 FL NITs (CAP, HSI, FLI, USFLI) among themselves and to CAP value of 285 dB/m and 5 fibrosis NITs (transient elastography, APRI, NFS, FIB-4, HEPAmet) among themselves and to LSM ≥8.7 kPa.Among 2,051 participants (average age 47 (±17.7), 48% males, 62% white, 73% overweight/obese, 39% metabolic syndrome), demographics were similar among NIT groups (CAP = 812; HSI = 1,234; FLI = 935; USFLI-824). FL prevalence by NIT: 39% CAP, 58% HSI, 47% FLI, 37% USFLI. Advanced fibrosis prevalence by test: LSM (≥8.7 kPa) 10-14%; FIB-4 (≥2.67) and APRI (≥0.7) 1.3-2.7%; HEPAmet (>0.47) 14-21%. Compared to CAP ≥285, FLI (AUROC = 0.823) and USFLI (AUROC = 0.833) performed better than HSI (AUROC: 0.798). Compared to LSM ≥8.7 kPa, only NFS (AUROC = 0.722) performed well (FIB-4 AUROC = 0.606; APRI = 0.647; HEPAmet = 0.629). Among the CAP cohort, the strongest FL predictor was obesity (OR: 15.2, 95% CI: 7.97-28.9, p < 0.001); the only fibrosis predictor was elevated AST (OR: 1.06, 95% CI: 1.00-1.12, p = 0.04). The addition of CAP or LSM as a second NIT reduced the number of indeterminate patients especially for FL.Regardless of diagnostic method in 2017-2018, the prevalence of NAFLD was >35%. NITs for FL performed well but not for advanced fibrosis. CAP and LSM as a second NIT reduced those considered indeterminate.