Noninvasive tests for nonalcoholic fatty liver disease in a multi-ethnic population: The HELIUS study

Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence and severity globally, prompting noninvasive testing, yet limited data exist on noninvasive liver tests (NITs) including transient elastography (TE) in ethnically diverse populations. Therefore, we studied prevalence and ethnic differences in NAFLD with NITs in the multi-ethnic HEalthy Life In an Urban Setting (HELIUS) cohort. NITs of liver steatosis (Fatty Liver Index [FLI]) and fibrosis (Fibrosis-4 index [FIB-4], and aspartate aminotransferase-to-platelet ratio [APRI]) were assessed in 10,007 participants. A subpopulation of 399 participants, selected on high-risk criteria for NAFLD (obesity, type 2 diabetes mellitus [T2DM], and/or elevated NITs), was examined with TE. FLI was >= 60 in 27.3% of 10,007 participants, indicating steatosis. Most participants (71.8%) had FIB-4 < 1.30, excluding advanced liver fibrosis, and 1.1% (n = 113) had high FIB-4 (FIB-4 >= 2.67), indicating likely advanced liver fibrosis. In the TE subpopulation, 37.8% and 17.3% had steatosis and fibrosis (continuation attenuation parameter [CAP] >= 280 dB/m, liver stiffness measurement [LSM] >= 7.0 kPa, respectively). Turkish participants had highest adjusted odds ratio (OR) for elevated LSM (1.72, 95% confidence interval [CI] 0.59-5.01) and Ghanaians the lowest (0.24, 95% CI 0.09-0.65). Ghanaians had lowest adjusted OR for elevated CAP: 0.18 (95% CI 0.09-0.37). In diabetics, CAP and LSM were 17.6% and 14.6% higher than in nondiabetics, respectively. Correlations of FIB-4 and APRI with LSM were absent and weak. Conclusion: Liver steatosis proxy FLI was elevated in 27.3% of this multi-ethnic population. In Turkish background and in those with T2DM, proxies for steatosis and fibrosis were high, whereas in Ghanaian background, NITs were generally low. Together, this warrants awareness for NAFLD among high-risk populations, taking ethnic background into account. The absence of clear correlation between FIB-4 and APRI with LSM questions the accuracy of these fibrosis NITs to detect advanced fibrosis in the general population.