Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)
Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)—formerly known as Nonalcoholic Fatty Liver Disease (NAFLD)—is currently the most common chronic liver disease globally, affecting roughly 30%–38% of the adult population as of 2026.
Key Characteristics and Nomenclature
- Definition: The presence of hepatic steatosis (fat in more than 5% of liver cells) along with at least one cardiometabolic risk factor (e.g., obesity, type 2 diabetes, or hypertension) and minimal to no alcohol intake.
- Former Name: Previously known as Nonalcoholic Fatty Liver Disease (NAFLD). The name was changed in 2023 to reduce stigma and emphasize the metabolic drivers of the disease.
- Spectrum of Severity: MASLD ranges from simple fat accumulation (MASL) to a more severe, inflammatory form called MASH (Metabolic Dysfunction-Associated Steatohepatitis, formerly NASH), which can progress to cirrhosis and liver cancer.
Risk Factors and Diagnosis
- Primary Risks: Obesity (especially central/belly fat), Type 2 diabetes, insulin resistance, high cholesterol, and hypertension.
- "Lean MASLD": Up to 20% of cases occur in people with a normal body mass index (BMI), often due to genetic factors or metabolic unhealthy status.
- Common Symptoms: Often a "silent disease" with no symptoms. When present, symptoms may include fatigue, weakness, or dull pain in the upper right abdomen.
- Diagnostic Tools: Usually detected via routine blood tests (elevated liver enzymes) or abdominal ultrasound. Advanced staging utilizes non-invasive tests like FIB-4 scores and FibroScan (transient elastography).
Management and Treatment
Lifestyle (Cornerstone): Weight loss of 5% to 10% is the primary treatment and can reverse liver fat and inflammation. Recommended approaches include the Mediterranean diet and at least 150 minutes of moderate exercise per week.
Approved Medications:
Lifestyle (Cornerstone): Weight loss of 5% to 10% is the primary treatment and can reverse liver fat and inflammation. Recommended approaches include the Mediterranean diet and at least 150 minutes of moderate exercise per week.
Approved Medications:
- Resmetirom (Rezdiffra): The first drug approved (2024) specifically for adults with non-cirrhotic MASH and moderate-to-advanced liver scarring.
- Semaglutide: Received expanded FDA indication (August 2025) for treating MASH with moderate-to-advanced fibrosis.
- Comorbidity Control: Managing underlying diabetes, high blood pressure, and high cholesterol is essential, as cardiovascular disease is the leading cause of death for those with MASLD.
