African Americans have a distinct clinical and histologic profile with lower prevalence of NASH and advanced fibrosis relative to Caucasians

Abstract

Background and aims: Racial/ethnic disparities have been reported in the prevalence of nonalcoholic fatty liver disease (NAFLD). Thus, we aimed to understand the inter-ethnic clinical, biochemical, and histological differences in a large cohort of Caucasians and African-Americans (AA).

Methods: Laboratory and liver biopsy data of 942 NAFLD patients were retrospectively analyzed. Nine hundred seven patients were included in the analysis: 677 (74.6%) Caucasians and 230 (25.3%) AA.

Results: AA had higher mean BMI compared to Caucasians (42.6 ± 9.5 vs. 39 ± 8.6 kg/m2). The prevalence of nonalcoholic steatohepatitis (NASH), defined by NAFLD activity score (NAS . 5), was higher in the Caucasians (n = 67) compared to AA (n = 7) (9.8% vs. 3%, P = 0.0007). One hundred fifteen patients (12.8%) had advanced fibrosis: 109 (16.2%) Caucasians and six (2.6%) AA. No AA patients had stage 4 fibrosis or cirrhosis. Multivariate logistic regression analysis revealed advanced fibrosis was significantly associated with age at liver biopsy (OR 1.03, 95% CI 1.0.1.1, P = 0.017, lower platelet count (OR 0.99, 95% CI 0.98.0.99, P = <0.0001), AST/ALT ratio (OR 5.19, 95% CI 2.9.9.2, P <0.0001) and Caucasian race (OR 7.49, 95% CI 2.53.22.2, P = 0.0003). Advanced fibrosis in AA was predicted by lower platelet count and AST/ALT ratio. Whereas Advanced fibrosis in Caucasians was predicted by age at biopsy, lower platelet count and AST/ALT ratio.

Conclusion: The AA have a distinct clinical and histologic phenotype. Caucasians have a significantly greater proportion of NASH and are eight times more likely to develop advanced fibrosis than AA.