Fatty liver disease (MASLD)

Many people first hear the words "fatty liver" after a routine blood test shows high liver enzymes, or an ultrasound done for something else mentions it. It can be confusing, especially when you feel fine. The good news is that fatty liver disease often improves, and sometimes reverses, with steady changes in daily habits. The key questions are how much the liver has been affected and what plan fits your life. Dr. Pimienta, who is triple board-certified, including in gastroenterology and obesity medicine, sees adults from across Los Angeles County for fatty liver disease, in English or Spanish.

What are MASLD and MASH?

Fatty liver disease means extra fat has built up in the liver. In 2023, liver experts gave it a new name to describe it more accurately: MASLD, which stands for metabolic dysfunction-associated steatotic liver disease. You may also see the older name, nonalcoholic fatty liver disease (NAFLD). "Steatotic" simply means fatty, and "metabolic" means it is linked to things like weight, blood sugar, blood pressure and cholesterol.

There are two main forms:

• Fat only, without much inflammation. This is the most common form. It usually does not harm the liver much on its own, but it is a signal to pay attention to your metabolic health.
• MASH (metabolic dysfunction-associated steatohepatitis), formerly called NASH. Here the fat comes with inflammation and liver cell injury. Over years, MASH can lead to scarring (fibrosis), and in some people to cirrhosis, which is severe scarring that can cause liver failure or liver cancer.

Experts estimate about 1 in 4 adults in the United States have fatty liver disease, and a much smaller share have MASH. The amount of scarring, more than the amount of fat, is what best predicts how the liver will do over time.

Does fatty liver cause symptoms?

Usually not, at least not for many years. Some people feel tired or have a dull ache in the upper right side of the belly, but most feel completely well. That is why fatty liver is most often found on tests: a high ALT or AST (liver enzymes) on routine blood work, or a "bright" or "fatty" liver on an ultrasound or CT scan. Our article on what your liver tests mean walks through those numbers. Normal liver enzymes do not rule out fatty liver or scarring.

Who is more likely to have fatty liver disease?

Fatty liver disease is closely tied to metabolic health. It is more common in people who have:

• Overweight or obesity, especially extra weight around the waist
• Type 2 diabetes or prediabetes
• High triglycerides or low HDL ("good") cholesterol
• High blood pressure
• Sleep apnea, or a family member with fatty liver or cirrhosis

It also differs by background. In the United States, the NIH reports that fatty liver disease is most common among Hispanic adults, likely because of a mix of genes and higher rates of diabetes. Asian Americans can develop it at a lower body weight. This matters for many families in Los Angeles, and it is a reason to ask about your liver if diabetes or fatty liver runs in your family. It is not a reason for blame: genes play a real part.

Alcohol also matters. Drinking adds to the damage, and when someone with metabolic risk factors also drinks more than a moderate amount, doctors call it MetALD.

How does Dr. Pimienta check the liver?

He begins by listening: your health history, medicines and supplements, alcohol use, family history and past test results. Then he examines you and orders only the tests that fit.

1. Rule out other causes

   Blood tests check for other liver conditions that can look similar, such as hepatitis B or C, iron overload or autoimmune liver disease, along with blood sugar and cholesterol.

2. Estimate scarring with a blood score

   The FIB-4 score uses your age, two liver enzymes and your platelet count to estimate the chance of significant scarring. A low score is reassuring for most people.

3. Measure liver stiffness if needed

   If the score is not low, a painless scan called elastography may be arranged. The best known is FibroScan (transient elastography), which uses a gentle pulse and ultrasound to measure how stiff the liver is. Stiffer usually means more scarring. Other options include a specialized blood test or MRI elastography.

4. Put it together

   With these results, Dr. Pimienta explains your stage of liver health in plain words and how often to recheck it. A liver biopsy is rarely needed.

What helps fatty liver disease?

Steady lifestyle change is the foundation of treatment, and it works. National liver guidance describes the benefit of weight loss in steps:

About 5% of body weight

Less fat in the liver

About 7 to 10%

Less inflammation in many people

10% or more

Scarring can improve

150 minutes a week

Moderate activity helps, even before the scale moves

• Gradual weight loss. For someone who weighs 200 pounds, 5 to 10 percent is 10 to 20 pounds. Slow and steady is safer for the liver than crash dieting. When weight has been hard to change, Dr. Pimienta also offers medical weight management.
• A Mediterranean-style eating pattern. Vegetables, beans, whole grains, fish, nuts and olive oil, with fewer sugary drinks, sweets, white flour and ultra-processed foods. Cutting out soda and juice is one of the most useful single steps.
• Regular activity. Brisk walking, swimming or cycling count. Activity helps the liver even without weight loss.
• Less alcohol, or none. Alcohol adds to liver injury, so less is better. People with significant scarring should avoid it completely.
• Diabetes, cholesterol and blood pressure care. Heart disease is a leading cause of illness in people with fatty liver, so these matter as much as the liver itself. Some diabetes and weight medicines, such as GLP-1 medicines, may also benefit the liver.
• Vaccines for hepatitis A and B if you are not already protected.

For adults with MASH and moderate to advanced scarring who do not have cirrhosis, the FDA has recently approved the first medicines made for this condition, used together with diet and exercise. They are not right for everyone. Your plan depends on your health; Dr. Pimienta will talk with you about what fits you, and you decide together. Our article on GLP-1 medicines and your digestion covers one group of these medicines.

People who already have cirrhosis need extra care, including regular checks for liver cancer, usually with an ultrasound every 6 months.

When is liver disease an emergency?

Make a regular appointment if you have high liver enzymes on more than one test, a scan that mentions fatty liver, diabetes with any sign of liver trouble, or a family member with cirrhosis.

Getting seen in Los Angeles

Dr. Pimienta sees patients in person on Wilshire Boulevard, near the Miracle Mile and Beverly Hills, and by secure video for patients in California. He accepts Medicare; other patients are seen as self-pay, with pricing explained before anything is booked. Bring recent blood tests and any liver imaging reports. Request an appointment or call (424) 281-7392.

Questions patients ask

References

1. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Definition and Facts of NAFLD and NASH.
2. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Symptoms and Causes of NAFLD and NASH.
3. American Association for the Study of Liver Diseases (AASLD). Clinical Assessment and Management of Metabolic Dysfunction-Associated Steatotic Liver Disease. 2023.