Metabolic dysfunction-associated steatotic liver disease (MASLD) affects about 100 million people in the United States.
Here, Jaideep Behari, MD, director of the UPMC Liver Steatosis and Metabolic Wellness Program, answers your questions about MASLD. Read on to discover the causes and symptoms of MASLD, along with treatment options for this disease.
What Is MASLD?
MASLD stands for metabolic dysfunction-associated steatotic liver disease. Once called nonalcoholic fatty liver disease (NAFLD), the name changed in 2023 to reflect its close association with common metabolic disorders.
With MASLD, there are excessive amounts of fat in the liver. This can lead to scarring of the liver, called cirrhosis, and liver failure.
The term “metabolic dysfunction-associated” refers to excessive fat in the liver. But this isn’t a result of alcohol use, but from the presence of other metabolic or metabolism-related dysfunction in your body.
A MALSD diagnosis requires evidence of increased fat in the liver (usually found by imaging studies of the abdomen or by a liver biopsy), absence of excessive alcohol use, and at least one of the following metabolic disorders:
- High body weight or obesity.
- Hypertension (high blood pressure).
- Low level of HDL-cholesterol or high triglyceride.
- Type 2 diabetes or prediabetes.
How Common Is MASLD?
Roughly one in three people in the United States has MASLD, according to current estimates. But not every person develops advanced liver disease.
The real challenge is telling apart the people who have advanced disease from those who have mild disease. Because in most cases, this condition has no associated symptoms.
For someone who has type 2 diabetes, there’s about a 70% chance that they have MASLD. For someone who has obesity, the chances of having MASLD also go up. And for anyone with a body mass index (BMI) of 40 kg/m2 or greater, the prevalence of MASLD is more than 90%.
So, this is a surprisingly common condition.
Who Is at Risk for MASLD?
Some subgroups of people are at increased risk of scarring of the liver and development of cirrhosis. These subgroups include:
- People who have severe obesity, which we define as individuals who have a body mass index of more than 40 kg/m2.
- People who have type 2 diabetes.
- People who have multiple components of THE metabolic syndrome.
Metabolic syndrome refers to a group of metabolic problems that tend to occur together, such as:
- High blood pressure.
- High cholesterol.
- Insulin resistance.
- Obesity.
- Type 2 diabetes.
The more metabolic syndrome components a person has, the greater their risk of developing MASLD and MASLD-related liver scarring and, ultimately, developing cirrhosis.
How Does MASLD Affect the Liver?
MASLD can affect the liver in many ways.
The presence of excessive fat in the liver can affect the functioning of liver cells (hepatocytes). Once hepatocytes fill with fat, it affects their ability to metabolize, or absorb, nutrients, and handle carbohydrates, fat, and protein that must pass through the liver.
Once the liver develops excessive fat, it becomes resistant to the effects of insulin. Known as insulin resistance, this can increase the risk of developing type 2 diabetes.
The liver can also become inflamed. An inflamed liver produces proteins that alert the rest of the body to inflammation — that damage and injury are taking place. These changes can then start affecting the function of other organs.
It’s important to understand the relationship between MASLD and the risk of developing cirrhosis.
In someone who has increasing scarring of the liver and repeated cycles of injury in the liver, followed by regeneration and then additional scarring, MASLD can progress to very extensive scarring called cirrhosis.
Even if someone has cirrhosis, it doesn’t mean that the liver will shut down the next day. If they change their lifestyle and receive appropriate treatment, they can live for a long time. They may even outlive their liver disease.
What Are the Stages of MASLD?
There are many stages of MASLD. Staging typically depends on the amount of scarring of the liver. Most people are in the earliest stage of the disease.
Studies show that people with very little liver scarring are generally not at very high risk of developing cirrhosis, liver cancer, or liver failure. So, people who have stage 0 or stage 1 scarring are generally considered to be at low risk.
But someone who has stage 2 or 3 scarring, meaning a moderate or severe amount of scarring throughout the liver, is at increased risk. By treating their fat, liver inflammation, and scarring in the liver, we can decrease their risk of developing cirrhosis in the future.
The highest risk group includes people with stage 4 scarring, called cirrhosis. They can develop complications, liver failure, and liver cancer.
How Is MALSD Diagnosed?
The first step of screening for MASLD is a test called the Fibrosis-4 index. This simple test, which any doctor can perform in their office, relies on three blood tests and the individual’s age. Once we put these factors into a formula, we can quickly decide whether the person is at high risk of developing liver disease.
The good news is that the vast majority of people will never need to see a liver specialist or a gastroenterology specialist. That’s because they’ll be in the lower risk category and can be safely monitored long-term by their PCPs.
Some people who fall into high-risk subgroups see their primary care doctors for testing to see where they are in this process of scarring of the liver. We call this a noninvasive liver fibrosis assessment, which we perform through a variety of tests. Most commonly, a clinic-based quick and safe test called Fibroscan.
How Is MASLD Treated?
Treatment of MASLD depends on:
- How advanced the disease is.
- Other problems the individual has.
- The effort it would take for them to improve their lifestyle.
So, one way to think about this is to classify treatment based on the severity of the disease.
The majority of people will have low-risk MASLD. These individuals have only stage 0 or stage 1 scarring of the liver.
Anyone in the early stages can safely stay with their PCP. They should see a dietitian or nutritionist as appropriate and make other appropriate lifestyle changes. This may include minimizing or avoiding alcohol consumption and increasing physical activity to decrease the risk of progression of MASLD.
Someone with stage 2 or 3 fibrosis should see a gastroenterologist or a liver specialist, especially those who have:
- Multiple components of metabolic syndrome.
- Persistently elevated liver enzymes, which suggest an ongoing process of inflammation in the liver.
- Severe obesity.
- Type 2 diabetes.
Someone who has cirrhosis should absolutely seek a referral to a specialist center, where they can be closely monitored and treated.
What Are the Most Common Misconceptions About MASLD?
A common misconception about MASLD is that it’s always associated with high body mass index or obesity.
It’s quite common for us to see people who are thin. We call this condition “lean MASLD.” So, it’s important to realize that diet and lifestyle can affect individuals who are thin, those who don’t have obesity, and people who aren’t overweight.
It’s also important to realize that an absence of symptoms doesn’t mean that someone may not have advanced liver disease. Many people have MASLD without symptoms.
Another common misconception is that we can’t do anything about it. There’s a lot that someone can do about MASLD once it’s diagnosed.
Changes every person can make include:
- Drinking less alcohol.
- Improving their diet.
- Increasing physical activity.
- Stopping smoking and using tobacco.
- Treating their dyslipidemia, blood pressure, and diabetes to decrease the risk of MASLD-associated heart disease.
These changes can go a long way in helping minimize the effects of MASLD.
Why Does Your Liver Health Matter?
The liver is very important to our overall health, especially our metabolic health.
An inflamed or fatty liver that has developed MASLD can increase the risk of developing problems outside the liver. This may include developing problems in other organs, such as the heart, pancreas, and kidneys.
There are several things that people interested in keeping their livers healthy for their whole lifetime should keep in mind.
Everything that we eat filters through the liver. Our blood flow is set up so that everything we consume by mouth, whether it’s food, liquids, or medications, goes into our stomach. Then our intestines absorb it, and that blood flow then goes through the liver.
The liver then extracts all the nutrients it needs. It puts back all of the products, proteins, fat, and carbohydrates it produces for the rest of the body to use.
The liver has more than 500 known metabolic functions, and I suspect many more unknown functions that we’ve yet to discover. So, it’s a critical organ for overall health. A liver that’s starting to look unhealthy through the diagnosis of MASLD is an early sign of future problems throughout the body.
Why Should I Care About MASLD?
There are several reasons why you should care about a diagnosis of MASLD.
First and most important, from a purely liver-related perspective, is that for some people, the disease can progress to cirrhosis and liver failure. This can be life-threatening. In many cases, we must consider liver transplantation for them.
A second reason is that having excessive amounts of fat in the liver can increase your long-term risk of developing type 2 diabetes, heart disease, and other chronic conditions. This even applies to someone who’s young and otherwise healthy.
A liver that has excessive amounts of fat in it becomes insulin-resistant. Once the liver becomes insulin-resistant and inflamed, it affects the functioning of the entire body. With our whole body connected, the liver plays an important role in metabolic regulation.
Having MASLD is like a canary in a metabolic coal mine. You may have years or sometimes decades before other complications, like type 2 diabetes or cardiovascular disease, develop.
For someone diagnosed with MASLD, either at an early stage or young age, it’s important for them to make the necessary changes in their lifestyle so they can avoid:
- Decrease the risk of developing cirrhosis and its complications.
- Developing other complications outside the liver.
- Having to take medications.
Why Choose UPMC for MASLD Care?
At UPMC, we’ve worked hard for many years to develop a comprehensive program for the care of people who have MASLD.
The UPMC Liver Steatosis and Metabolic Wellness Program, located at UPMC Presbyterian, cares for people with MASLD and other complex metabolic conditions.
We have a network of doctors, including PCPs and liver specialists, who work closely with us. Together, we help people get the appropriate treatment at the appropriate time.
For those who come to us at very advanced stages of a disease and need a liver transplant, we work with our transplant program.
To learn more about our program, visit our website.