MASLD and Sarcopenia

Comprehensive Summary: MASLD and Sarcopenia

Lecturer: Zobair Younossi, MD

1. Main Clinical Topics Discussed

• Epidemiology, disease stratification, and treatment of Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD, formerly NAFLD/NASH)
• Extra-hepatic manifestations of MASLD
• Sarcopenia: importance, assessment, and treatment in the context of MASLD
• Nomenclature evolution (NAFLD → MASLD; NASH → MASH)

2. Key Learning Points, Guidelines, and Recommendations

Disease Characterization:

• MASLD is defined by hepatic steatosis in the context of metabolic risk factors; MASH (formerly NASH) is a histological diagnosis requiring biopsy confirmation
• Disease progression is non-linear: patients may progress, regress, or remain stable — complicating clinical trial design with fibrosis as a surrogate endpoint
• Two major drivers of disease: Type 2 diabetes (T2D) and visceral/central obesity

HCC Risk Stratification:

• MASLD-related HCC can occur in the absence of cirrhosis, unlike most other chronic liver diseases
• HCC incidence without cirrhosis: 0.1–1.3 per 1,000 patient-years — below standard screening thresholds
• Screening should be considered in higher-risk subgroups: family history of HCC, diabetes, or specific genetic profiles ("case finding" rather than population screening)
• Once cirrhosis is established: HCC risk ~2–3% per year, meeting standard surveillance thresholds

Fibrosis as a Prognostic Marker:

• Stage ≥F2 fibrosis is associated with significantly increased liver-related and all-cause mortality
• Fibrosis regression (observed in ~16% of patients over 48 weeks in cirrhotic trial data) is associated with reduced liver-related clinical events
• FIB-4 is recommended as first-line non-invasive risk stratification tool (originally developed for Hepatitis C, now widely adopted for MASLD)

Liver Transplantation:

• MASH is the #1 indication for liver transplantation for HCC in the United States
• MASH is the #1 indication in women and patients >55 years of age for liver transplantation overall
• For non-HCC decompensated liver disease, MASH is the #2 indication nationally

3. Specific Clinical Data and Study Results Cited

Global Prevalence (Most Recent Meta-analysis):

• Global MASLD prevalence: ~30% overall; ~38% based on most recent studies
• Regional breakdown: North America ~33%, Middle East/North Africa ~36%, Latin America >40%
• MASH prevalence: estimated ~5% globally (higher in Middle East/North Africa and Latin America)

Pediatric MASLD:

• Earlier estimates: 7.6% prevalence in children
• More recent NHANES adolescent data: ~15%; estimated true prevalence 15–20%

MASLD in Type 2 Diabetes:

• 2018 meta-analysis: prevalence ~55%
• Most recent meta-analysis: ~65–69%; Middle East prevalence ~71%

Cirrhosis and Mortality:

• MASLD-related cirrhosis prevalence: ~0.5–1.5% in the general population; ~5% among MASLD patients
• Cirrhosis-related mortality: ~7 per 100 patient-years
• Leading causes of death in MASLD patients: (1) Cardiovascular, (2) Extra-hepatic cancers, (3) Liver disease — together accounting for ~67% of all deaths
• In advanced fibrosis (F3–F4): liver disease becomes the #1 cause of death

Global Burden of Disease (GBD) Data (2010–2019):

• MASLD-related HCC and cirrhosis deaths are increasing in nearly every world region
• Hepatitis B-related cirrhosis