When you think about metabolic health, you might focus on weight, blood sugar, or heart health. But your liver plays an important role, too. Conditions such as obesity, Type 2 diabetes, high blood pressure, and abnormal cholesterol levels can increase your risk of liver damage.
Steatotic liver disease, once commonly known as fatty liver disease, takes several forms. The most common is metabolic dysfunction-associated steatotic liver disease (MASLD), previously called nonalcoholic fatty liver disease (NAFLD). Some people with MASLD go on to develop liver inflammation and scarring, reflecting a more advanced stage called metabolic dysfunction-associated steatohepatitis (MASH), previously known as nonalcoholic steatohepatitis (NASH).
Because these conditions often develop over years without symptoms, many people don't realize they may be at risk until liver damage has already progressed. To learn more about liver disease risk, early detection, and testing options, we spoke with Dr. Margery Connelly, PhD, MBA, FAHA, strategic director of diagnostics research and development at Labcorp.
What is metabolic dysfunction-associated steatotic liver disease (MASLD)?
MASLD is a spectrum of liver conditions caused by excess fat in the liver. It ranges from mild to more advanced:
- Steatosis, or fatty liver: Excess fat has built up in the liver
- MASH: The liver has excess fat along with inflammation and, in some cases, fibrosis (scarring)
- MASH-related cirrhosis: Liver scarring has progressed to a more advanced stage of liver disease and may no longer function normally
An important stage is at-risk or fibrotic MASH, when liver scarring is present. "People who reach this stage have a greater risk of progressing to cirrhosis," says Dr. Connelly.
How is MASLD connected to metabolic dysfunction?
Excess fat around your organs, called visceral fat, disrupts the signals your organs use to communicate with each other, and your metabolic pathways become impaired. Over time, it can lead to signs of metabolic syndrome, including excess abdominal fat, high blood sugar, high blood pressure, high cholesterol, and high triglycerides.
As fat continues to build up throughout the body, metabolic syndrome can progress into chronic conditions such as Type 2 diabetes, obesity, and heart disease. "A similar process occurs in the liver," says Dr. Connelly, "where excess fat can contribute to MASLD and MASH."
What are the symptoms of MASLD?
Early MASLD and MASH can be difficult to recognize because the liver can continue functioning even while inflammation is present. Symptoms may not appear until the disease becomes more advanced and may include:
- Fatigue
- Low energy
- Mild discomfort in the upper right side of your abdomen (where your liver is)
- Loss of appetite
Symptoms alone aren't a reliable way to catch MASLD early. That's why understanding your risk factors matters just as much.
When should you get tested for MASLD?
While age can play a role in MASLD risk, testing is usually recommended based on a person's overall risk factors. Talk to your provider about getting tested if you have one or more of the following:
- Obesity
- Type 2 diabetes
- High blood pressure
- Dyslipidemia (high cholesterol or triglycerides)
MASH and early-stage liver scarring can be reversible when identified and treated early, which is why screening at the first sign of risk is so important. That includes younger people, such as teens and young adults who are overweight or obese.
How do doctors check for MASLD and MASH?
Standard liver enzyme tests like alanine aminotransferase (ALT) and aspartate aminotransferase (AST) can offer a general picture of liver health, but they aren't always reliable for identifying liver disease, since enzyme levels can remain normal even as inflammation or scarring develops.
A more advanced blood test, such as the NASHnext® Advanced Liver Risk Test (NIS4®), measures four biomarkers in the blood related to inflammation and liver fibrosis. The results are combined into a single score to help estimate your risk for at-risk or fibrotic MASH.
Because the test provides a risk score rather than a diagnosis, your provider can use the results to guide next steps and additional testing. Doctors may also use imaging, such as an ultrasound, magnetic resonance imaging (MRI) and/or elastography (MRE), or even a liver biopsy, for a clearer picture.
How is MASLD treated?
MASLD and MASH can often be reversed, especially if caught before advanced scarring or cirrhosis develops. Lifestyle changes such as healthy eating, physical activity, and weight loss can help reduce liver fat and inflammation. For some people, GLP-1 medications (a type of weight-loss treatment) may also be part of the recommended treatment plan, particularly when obesity or Type 2 diabetes is a factor.
Talk with your healthcare provider about your risk factors and whether liver testing may be right for you.
