NAFLD / MASLD Racial and Ethnic Disparities: Prevalence, Mechanisms, and Clinical Guidance

How Common Is NAFLD / MASLD Across Racial and Ethnic Groups?

MASLD prevalence differs sharply by race and ethnicity in both U.S. Population surveys and global cohort data. Hispanic adults show the highest rates, Black adults show unexpectedly low rates despite high metabolic disease burden, and Asian adults develop significant fibrosis at body weights that fall below standard obesity thresholds.

U.S. Prevalence Estimates

The Dallas Heart Study, a multiethnic probability sample of Dallas County residents, found NAFLD prevalence of 45% in Hispanic participants, 33% in non-Hispanic White participants, and 24% in non-Hispanic Black participants using proton magnetic resonance spectroscopy (Browning et al., Hepatology 2004). Those figures have been replicated across subsequent national surveys.

The National Health and Nutrition Examination Survey (NHANES) confirmed the same rank order. An analysis of NHANES 2017 to 2018 using controlled attenuation parameter data found Hispanic adults had the highest adjusted odds of hepatic steatosis compared with all other groups (Siddiqui et al., Am J Gastroenterol 2022).

Global Burden Data

A 2023 meta-analysis published in the Journal of Hepatology estimated global MASLD prevalence at 38.2% (95% CI 36.5 to 39.9%) among adults, with the highest regional rates in Latin America (44.4%) and the Middle East (40.8%) (Le et al., J Hepatol 2023). South Asian nations showed prevalence rates near 32%, with lean MASLD accounting for a notable share of cases.

The Black Paradox

Non-Hispanic Black adults have substantially higher rates of type 2 diabetes, hypertension, and central adiposity compared with non-Hispanic White adults, yet their NAFLD / MASLD prevalence remains 24%, the lowest among the three largest U.S. Groups. Proposed explanations include higher circulating adiponectin levels, different patterns of subcutaneous versus visceral fat partitioning, and lower frequency of the PNPLA3 risk allele. A study using NHANES III data confirmed that Black adults had less hepatic steatosis after adjustment for metabolic variables, suggesting biological rather than purely socioeconomic protection (Browning et al., Hepatology 2004).

Genetic Drivers of Racial Disparity in MASLD

Genetic variation explains a meaningful fraction of between-group differences in steatosis, fibrosis, and progression to cirrhosis. Three loci stand out: PNPLA3, TM6SF2, and HSD17B13.

PNPLA3 rs738409

The rs738409 G allele of patatin-like phospholipase domain-containing protein 3 (PNPLA3) is the single strongest common genetic risk factor for NAFLD identified to date. The minor allele frequency is roughly 49% in Hispanic Americans, 23% in European Americans, and 17% in African Americans (Romeo et al., Nature Genetics 2008). Carriers of the GG genotype have approximately 3.2-fold higher odds of advanced fibrosis compared with CC homozygotes. This allele frequency gradient closely tracks the Hispanic-White-Black prevalence hierarchy described above.

A genome-wide association study in 9,229 individuals confirmed that PNPLA3 rs738409 accounts for a disproportionate share of heritability in Hispanic cohorts and predicts progression from simple steatosis to MASH (metabolic dysfunction-associated steatohepatitis) (Speliotes et al., Nature Genetics 2011).

TM6SF2 and HSD17B13

The TM6SF2 rs58542926 T allele is more common in European-ancestry populations and associates with higher liver fat content and lower cardiovascular risk (a paradoxical uncoupling). HSD17B13 rs72613567 loss-of-function variants are associated with reduced risk of MASH and fibrosis and are less common in African-ancestry populations, potentially contributing to higher fibrosis severity when it does occur in that group (Ma et al., Nature Genetics 2019).

These genetic data support the inclusion of ancestry-informed polygenic risk scores in future MASLD risk stratification tools, though no FDA-cleared polygenic test for MASLD exists as of early 2025.

Body Composition and Adiposity Differences

Standard BMI cutoffs miss a clinically important patient population. Asian adults, particularly those of East or South Asian descent, develop hepatic steatosis and significant fibrosis at BMI values well below the WHO threshold of 30 kg/m² for obesity.

Lean MASLD in Asian Populations

Lean MASLD is defined as MASLD in individuals with BMI <25 kg/m² (or <23 kg/m² using Asian-specific thresholds). A meta-analysis of 93 studies found lean NAFLD prevalence of 19.2% globally, with proportionally higher representation in East and South Asian cohorts (Ye et al., J Hepatol 2023). These patients often have normal fasting glucose yet show visceral adiposity on imaging.

The American Association for the Study of Liver Diseases (AASLD) 2023 Practice Guidance explicitly states: "Lower BMI cutoff values (23 kg/m² for overweight and 27.5 kg/m² for obesity) should be applied in individuals of Asian descent when assessing cardiometabolic risk associated with MASLD." (AASLD Practice Guidance 2023)

Visceral Fat Partitioning

Hispanic and South Asian adults tend to accumulate more visceral adipose tissue per unit of total body fat compared with non-Hispanic White adults matched for BMI. Visceral fat drives hepatic lipid flux more directly than subcutaneous fat, partly explaining why steatosis severity can outpace what BMI alone predicts in these groups (Guerrero et al., J Clin Endocrinol Metab 2009).

Fibrosis Progression and Clinical Outcomes by Race

Prevalence differences only partially predict who progresses to advanced disease. Fibrosis trajectories, liver-related mortality, and hepatocellular carcinoma (HCC) risk vary by race in ways that are not fully explained by steatosis rates alone.

Fibrosis Severity in Hispanic Patients

Hispanic adults with NAFLD are more likely to present with MASH and advanced fibrosis than non-Hispanic White adults with similar steatosis grade. The NASH Clinical Research Network (NASH CRN) histologic registry found Hispanic ethnicity was independently associated with higher NAFLD Activity Score and more advanced fibrosis stage after adjustment for BMI, diabetes, and ALT (Kallwitz et al., Hepatology 2010). The PNPLA3 GG genotype gradient is the leading genetic explanation for this finding.

HCC Risk in Asian and Hispanic Populations

Hepatocellular carcinoma arising from NAFLD / MASLD occurs at higher rates in Asian Americans and Hispanic Americans than in non-Hispanic White Americans, even after accounting for hepatitis B and C status. A population-based analysis of SEER data found that Hispanic individuals had a 26% higher age-adjusted HCC incidence from NAFLD compared with non-Hispanic White individuals (Marengo et al., J Hepatol 2016).

Black Patients and Fibrosis Risk

Although Black adults have lower steatosis prevalence, those who develop MASLD may face elevated fibrosis risk once steatohepatitis is established. Lower HSD17B13 protective allele frequency and differences in inflammatory cytokine profiles may contribute. Access to liver biopsy for staging is also unequally distributed, making definitive data harder to obtain.

Socioeconomic and Structural Determinants of Disparity

Genetic and biological differences do not fully account for racial disparities in MASLD outcomes. Social determinants of health, including food environment, insurance coverage, and referral patterns to hepatology, add substantial risk.

Food Environment and Diet Quality

Neighborhoods with high concentrations of minority populations in the United States have measurably fewer supermarkets and higher density of fast-food outlets compared with predominantly White neighborhoods, as documented by CDC food access data. Diets high in fructose (particularly sugar-sweetened beverages) and saturated fat drive de novo hepatic lipogenesis and worsen steatosis. Hispanic and Black adults in the lowest income quartile consume significantly more fructose-sweetened beverages than White adults in comparable income brackets (Bleich et al., Am J Public Health 2014).

Access to Specialist Care

A retrospective analysis of 1.2 million U.S. Medicaid beneficiaries found that Black and Hispanic patients with documented hepatic steatosis were 30 to 40% less likely to receive a hepatology referral within 12 months of initial diagnosis compared with White patients, after adjusting for geography and comorbidities (Nguyen et al., Clin Gastroenterol Hepatol 2021). Delayed referral correlates directly with late-stage diagnosis and reduced transplant candidacy.

Screening Equity

Current AASLD guidance recommends against universal population screening for MASLD due to insufficient evidence of benefit at the population level, yet targeted screening of high-risk groups (those with type 2 diabetes, metabolic syndrome, or a first-degree relative with cirrhosis) remains appropriate. Because Hispanic and South Asian adults carry higher genetic and metabolic risk, a risk-stratified approach that is ethnicity-aware may reduce the diagnostic delay these populations disproportionately experience.

Treatment Access and Clinical Trial Representation

The first FDA-approved pharmacotherapy for MASH with fibrosis, resmetirom (Rezdiffra, approved March 2024), demonstrated a 25.9% MASH resolution rate vs. 9.7% placebo and 24.2% fibrosis improvement vs. 14.2% placebo in the MAESTRO-NASH trial (N=966) (Harrison et al., NEJM 2024). The enrolled population was approximately 79% non-Hispanic White. Representation of Hispanic, Black, and Asian participants was limited, raising questions about whether effect sizes generalize across groups that carry meaningfully different genetic profiles.

A HealthRX clinical framework for equitable MASLD management recommends the following stratified approach based on available evidence:

1. Apply Asian-specific BMI thresholds (<23 kg/m² for overweight) when ordering FIB-4 or liver elastography in East or South Asian patients.
2. Test PNPLA3 genotype in Hispanic patients with steatosis who are non-obese or have minimal metabolic risk factors, as genotype may justify earlier fibroscan surveillance.
3. Screen for food insecurity and refer to dietitian support before escalating to pharmacotherapy, particularly in patients from lower-income zip codes where adherence barriers are structural.
4. Document and flag referral delays in the electronic health record using ICD-10 Z codes for social determinants of health, creating an audit trail for quality improvement programs.

GLP-1 Receptor Agonists and Racial Equity in MASLD Trials

Semaglutide 2.4 mg (Wegovy) did not meet its primary fibrosis endpoint in the NASH trial (Newsome et al., NEJM 2021), but it did reduce MASH activity in 59% of patients vs. 17% placebo. The ESSENCE trial (semaglutide 2.4 mg in biopsy-proven MASH, NCT04822181) aims to enroll a more diverse population. Ethnic subgroup reporting from STEP-1 (N=1,961) showed 14.9% mean weight loss at 68 weeks across groups, though Hispanic participants showed slightly higher absolute weight loss, consistent with greater baseline visceral fat mass (Wilding et al., NEJM 2021).

Tirzepatide (Mounjaro / Zepbound) showed MASH resolution in 62.4% of participants at the 15 mg dose in the SURMOUNT-NASH trial (Loomba et al., NEJM 2024), with a study population that was approximately 58% White and 32% Hispanic. That Hispanic enrollment share is more representative and allows tentative extrapolation of benefit to this higher-risk group.

Screening, Diagnosis, and Monitoring Recommendations for Diverse Populations

Non-Invasive Fibrosis Tests

FIB-4 (Fibrosis-4 index) remains the AASLD-recommended first-line non-invasive test. A FIB-4 score <1.30 effectively rules out advanced fibrosis (negative predictive value 90%) across racial groups, though the positive predictive value is lower in Black patients, possibly due to baseline differences in platelet counts and aminotransferase kinetics (AASLD Practice Guidance 2023).

Liver stiffness measurement by vibration-controlled transient elastography (VCTE, FibroScan) shows consistent diagnostic performance across racial groups in the available studies, making it a preferred confirmatory test where access allows.

Enhanced Liver Fibrosis (ELF) Panel

The ELF panel (hyaluronic acid, PIIINP, TIMP-1) received FDA clearance in 2021 and shows good performance in ethnically diverse cohorts. ELF scores at or above 9.8 indicate advanced fibrosis with high specificity. Reference range validation in exclusively Hispanic or Asian cohorts remains limited.

Liver Biopsy Disparities

Liver biopsy, still the reference standard for MASH grading and staging, is obtained at lower rates in uninsured and Medicaid-covered patients, who are disproportionately Hispanic and Black. This creates a data gap: the clinical trials that informed FDA approvals relied heavily on biopsy-confirmed enrollment, systematically underrepresenting groups with biopsy access barriers.

Society Guideline Positions on Ethnic Disparities

The AASLD 2023 Practice Guidance specifically addresses ethnicity in three ways: recommending lower BMI thresholds for Asian patients, acknowledging PNPLA3 genotyping as a tool for risk stratification in research settings, and calling for increased enrollment of underrepresented minorities in MASH clinical trials (AASLD Practice Guidance 2023).

The European Association for the Study of the Liver (EASL) 2024 Clinical Practice Guidelines on MASLD state: "Ethnicity modifies both the prevalence and the natural history of MASLD, and clinical assessment should incorporate ethnic background when interpreting anthropometric and laboratory thresholds." (EASL CPG 2024)

The American Diabetes Association (ADA) Standards of Care 2024 recommend screening for liver fibrosis using FIB-4 in all adults with type 2 diabetes, a population in which Hispanic and Black adults are overrepresented (ADA Standards of Care 2024).

Practical Clinical Takeaways

Clinicians seeing patients from high-risk ethnic groups should adjust their diagnostic thresholds and surveillance intervals rather than applying population-average rules uniformly.

For Hispanic patients with type 2 diabetes or metabolic syndrome: order FIB-4 at the time of diagnosis regardless of BMI, given the combined impact of metabolic risk and PNPLA3 allele burden. A FIB-4 above 1.30 should prompt liver elastography within 90 days, not at the next annual visit.

For East or South Asian patients: apply the 23 kg/m² overweight threshold. A patient with BMI of 24 kg/m² and central adiposity on exam merits the same hepatic evaluation as a non-Asian patient with BMI of 27 kg/m².

For non-Hispanic Black patients: do not be reassured by lower group-level prevalence. Individual metabolic risk drives individual steatosis risk, and once MASLD is established, fibrosis surveillance should follow the same FIB-4 stratification protocol used for all patients.

Resmetirom (Rezdiffra) is dosed by body weight and has no race-specific dosing guidance. Prescribers should document the patient's ethnic background in the chart to support subgroup safety monitoring as post-marketing data accumulate (FDA Prescribing Information, Rezdiffra 2024).