RACIAL DISPARITIES IN NAFLD-FIBROSIS RISK FACTORS IN THE UNITED STATES POPULATION

Background and Aims: Screening tools are needed for early detection of NAFLD-fibrosis. We aimed to identify risk factors for NAFLD-fibrosis in the multiethnic population of the U.S. and thus accelerate development of equitable screening tools.
Methods: National Health and Nutrition Examination Survey (NHANES) 2017-March 2020 datasets were analyzed. The study group included 6,661 adults (age ≥ 20 years) with vibration controlled transient elastography (VCTE) data. NAFLD-fibrosis thresholds were set by optimizing the sensitivity and specificity of the VCTE-CAP score and the stiffness score for differentiating steatosis grade 0 from grades 1-3 and distinguishing fibrosis stages 0-1 from stages 2-4. Logistic regression was used to determine odds ratios (ORs). Independent variables included age, sex, body mass index (BMI), smoking history, alcohol use, poverty, diabetes, and hypertension. Diabetes was defined by self-report, and/or hemoglobin A1c (HbA1c) ≥ 6.5%, and/or fasting plasma glucose ≥ 126 mg/dL. Participants with past and current viral hepatitis and alcohol-associated liver disease were excluded.
Results: NHANES 2017-March 2020 had 372 individuals with NAFLD-fibrosis, defined as VCTE-CAP ≥ 285 dB/m and stiffness ≥ 8.6 kPa. Non-Hispanic Black persons had a lower prevalence of NAFLD-fibrosis than non-Hispanic Whites (Fig.1A). The age-standardized weighted prevalence of NAFLD-fibrosis was about 7-fold higher in those with diabetes in the total population and in non-Hispanic White, Mexican American and Other race, but not in non-Hispanic Black (Fig.1C). The prevalence of NAFLD-fibrosis did not differ significantly between non-Hispanic Black persons with and without diabetes. After adjusting for age, sex, BMI, alcohol use, smoking status, and hypertension in multivariate logistic regression models, diabetes was not significantly associated with NAFLD-fibrosis in non-Hispanic Black persons (OR=1.26, 95%CI: 0.57-2.77), but it was associated in non-Hispanic White (OR=4.46, 95%CI: 2.87-6.91) and Mexican American persons (OR=5.61, 95%CI: 2.61-12.04) (Table 1). Similar results were obtained when NAFLD-fibrosis was defined by liver stiffness ≥8.6 kPa and CAP ≥ 263 dB/m, which had 90% sensitivity for detecting steatosis grade 0 vs.1-3. Of interest, non-Hispanic Black persons had a higher prevalence of diabetes than whites (Fig.1B). Thus, the disconnection between diabetes and NAFLD-fibrosis in non-Hispanic Black persons does not stem from a low prevalence of diabetes.
Conclusions: NHANES provides nationally representative data about the residential population of the U.S. NAFLD-fibrosis was not associated with diabetes in non-Hispanic Black persons, indicating that screening algorithms that rely on diabetes to identify people at high risk for NAFLD-fibrosis may inadvertently disadvantage non-Hispanic Black individuals (Supported in part by Pfizer).