Metabolic Risk Profiles for Hepatic Steatosis Differ by Race/Ethnicity: An Elastography-Based Study of US Adults

Abstract

Background and aims: Most population-based studies of risk profiles for liver steatosis have relied upon serum markers (e.g., ALT or FIB-4) or ultrasound steatosis index to define cases. We sought to examine racial/ethnic differences in metabolic risk factors associated with liver steatosis and fibrosis at the population level using elastography-based measures.

Methods: In total, 4509 adults completed vibration-controlled transient elastography (VCTE) with controlled attenuated parameter (CAP) examinations in the 2017-2018 National Health and Nutrition Examinations Survey. Race/ethnicity was self-identified; metabolic parameters included waist circumference, obesity, diabetes, hypertension, and hyperlipidemia. Primary outcome was steatosis defined by CAP score ≥ 280 decibels per meter and secondary outcome significant fibrosis by VCTE median stiffness ≥ 8 kilopascals. Race-specific logistic regression models were performed to assess the relationship between metabolic parameters and hepatic steatosis and fibrosis.

Results: Prevalence of elastography-based hepatic steatosis was > 30% for all race/ethnicities. Steatosis was associated with increasing waist circumference for all race/ethnicities (OR ranging 1.7-2.3, p < 0.01). Steatosis was associated with diabetes for Whites (OR 2.4, 95% CI 1.2-4.7), Asians (OR 3.0, 1.4-6.3), and Hispanics (OR 2.2, 1.3-3.6), but not Blacks (OR 1.3, 0.8-2.2); hypertension for Whites (OR 1.7, 1.3-4.7) and Asians (OR 2.1, 1.1-3.8); and hyperlipidemia for Blacks only (OR 2.2, 1.3-3.7). Of metabolic risk factors, higher odds of fibrosis were demonstrated with higher waist circumference per 10 cm increase (OR 2.1, 1.8-2.4) and diabetes (OR 2.5, 1.6-3.7), but the effect of diabetes was present in all racial/ethnic groups except Blacks (p-interaction < 0.05).

Conclusion: Blacks have a distinct metabolic phenotype for steatosis, while Asians, Whites, and Hispanics are more similar. Racial/ethnic differences in risk profiles are important to consider in prevention, screening strategies, and interventions for fatty liver disease.

Keywords: Nonalcoholic fatty liver disease; Population studies; Racial/ethnic differences; Ultrasound elastography.