Metabolic dysfunction-associated steatotic liver disease (MASLD), a common condition formerly known as NAFLD, is linked to serious health issues and requires careful diagnosis and lifestyle management.

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as nonalcoholic fatty liver disease (NAFLD), is a widespread condition affecting at least one-quarter of the world's population [1]. In the United States, it impacts approximately 80 million adults [3]. MASLD is characterized by fat accumulation in the liver, not primarily due to excessive alcohol consumption, and is closely linked to metabolic health issues [2].

This condition is not merely a liver issue; it significantly increases the risk of developing serious secondary diseases, including cardiovascular diseases (CVDs), type 2 diabetes mellitus, and a type of liver cancer called hepatocellular carcinoma (HCC) [1]. Its more severe, inflammatory form is known as metabolic dysfunction-associated steatohepatitis (MASH) [1].

Who is at Risk for MASLD?

MASLD is strongly associated with various cardiometabolic risk factors and other health conditions. These include:

Obesity, often accompanied by insulin resistance [1]
Dyslipidemia (abnormal cholesterol or triglyceride levels) [1]
High blood pressure (hypertension) [1]
Type 2 diabetes mellitus [1]
Obstructive sleep apnea [1]
Chronic kidney disease (CKD) [1]
Cardiovascular diseases (CVDs) [1]
Atrial fibrillation, a type of irregular heartbeat [5]
Ischemic stroke, particularly in younger adults, where fatty liver can be an underrecognized marker of vascular risk [6]
Hypothyroidism, with a high prevalence (22.4%) in individuals with NAFLD [8]

The frequency of serious secondary diseases, such as CVDs, CKD, HCC, and other cancers, tends to increase with the severity of MASLD [1].

Diagnosing MASLD and Assessing Liver Health

The primary goal in diagnosing MASLD is not just to detect fat in the liver, but to identify individuals who have significant liver scarring, known as fibrosis, which indicates a higher risk of progression and complications [2]. Current recommendations suggest evaluating adults who have type 2 diabetes, obesity or excess body fat with other metabolic risk factors, unexplained elevated liver enzymes, or incidental findings of liver fat on imaging [2].

The diagnostic process typically involves several steps:

Initial Assessment: This includes understanding the patient's metabolic health, assessing alcohol consumption to rule out alcohol-related liver disease, and excluding other potential liver conditions [2].
Fibrosis Risk Stratification: Noninvasive methods are crucial for assessing the risk of liver fibrosis. This often begins with blood tests, such as the FIB-4 score, followed by noninvasive imaging techniques when clinically appropriate [2, 3].
Staging Fibrosis: The stage of liver fibrosis helps guide treatment decisions and determines the need for closer monitoring [3].

Lifestyle Changes: The Cornerstone of Management

Lifestyle modification is considered the most important strategy for managing MASLD [7]. While specific dietary guidelines for MASLD are still evolving, general healthy practices often recommended for conditions like heart failure can be beneficial for overall cardiometabolic health, which is closely linked to MASLD [4]. These recommendations include:

Dietary Adjustments: Adopting a healthy eating pattern, such as the DASH (Dietary Approaches to Stop Hypertension) diet, may offer benefits [4].
Regular Exercise: Physical activity is beneficial, though specific recommendations regarding type and duration may vary [4].
Alcohol Consumption: Avoiding excessive amounts of alcohol is generally advised [4].
Smoking Cessation: Quitting smoking is crucial for overall health [4].
Salt Restriction: A moderate reduction in salt intake is often more effective than severe restriction [4].

Emerging Treatments for MASLD

Beyond lifestyle changes, new pharmacotherapy options for MASLD are emerging, with the goal of reducing liver fat, inflammation, and fibrosis [3]. One example is Resmetirom (MGL-3196), an orally active selective liver thyroid hormone receptor-beta (THR-β) agonist, which has shown promise in reducing liver fat content and improving MASH [8].

Regarding adjunctive therapies, a cross-sectional study found an inverse association between serum vitamin D levels and MASLD severity parameters in individuals with overweight or obesity [7]. However, a subsequent randomized controlled trial did not find that vitamin D3 supplementation, when added to lifestyle modification, significantly influenced these non-invasive parameters of MASLD severity [7]. This suggests that while vitamin D status might be related to MASLD, supplementation as a direct treatment requires further research.

Given the strong links between MASLD and other serious health conditions, early detection and comprehensive management, including lifestyle modifications and potentially emerging pharmacological treatments, are vital for improving long-term health outcomes.

Sources

This article summarises published research for a general audience. It is not medical advice — talk to a qualified clinician about your own situation. Need help finding one? Browse doctors.

Understanding Metabolic Dysfunction-Associated Steatotic Liver Disease

Who is at Risk for MASLD?

Diagnosing MASLD and Assessing Liver Health

Lifestyle Changes: The Cornerstone of Management

Emerging Treatments for MASLD

Sources