What is MetALD?

MetALD was first coined by liver experts in 2023 in response to an increasing patient population that had both metabolic risk factors and excessive alcohol use. The disease occurs in people who have liver fat, metabolic risk factors — such has obesity, prediabetes or diabetes, high blood pressure, or high cholesterol — and who have more than 10 alcoholic drinks per week for women or 15 for men.

Since 1990, the share of Americans who meet those criteria has more than doubled, according to some research. Almost one in 10 U.S. adults report overlapping heavy drinking and obesity, according to a recent study published in JAMA Internal Medicine, and national survey data found that young people were especially hit hard by these risk factors. According to the survey, people ages 26 to 34 years old have the most overlapping alcohol use disorder and obesity of any age group.

As a result, MetALD is now almost twice as common as alcohol-associated liver disease.

"If you drink alcohol, you are going to accumulate fat in the liver," said Juan Pablo Arab, a liver researcher, transplant hepatologist, and director of alcohol sciences at the Stravitz-Sanyal Institute for Liver Disease and Metabolic Health at Virginia Commonwealth University. "But what happens if you already have obesity and insulin resistance, and you already have fat in your liver?"

Women are especially at risk, as their higher body fat percentages and smaller reserve of enzymes that digest alcohol mean their bodies absorb more alcohol and take longer to process it than men's do. Women are also more likely to have obesity, which amplifies alcohol's effects and increases the risk of liver damage as well as other conditions, including cancer.

However, despite these risk factors for women, some research has found the prevalence of MetALD being lower in women, though it's unclear whether there's an actual sex difference or if women are just going undiagnosed.

Steven Klein, a physician at Caron Treatment Centers in Pennsylvania and one of the first U.S. doctors to openly prescribe GLP-1s as an addiction medication, said he believes a future where GLP-1s are used to curb addiction is coming quickly. His team has treated 440 addiction patients with GLP-1s in the past year and a half who had an average body mass index of 30, meaning they met the clinical threshold for obesity.

"Just looking at the numbers, the average patient in our program qualifies for an FDA-approved indication" for weight loss, Klein said.

However, experts note that many MetALD patients fall into a gray area where they don't meet the criteria for a diagnosis of obesity, diabetes, or alcohol use disorder. Others could be labeled as having MASLD but underreport their drinking. It's also unclear how much of the progression of MetALD is driven by obesity or diabetes compared to alcohol.

On top of that, experts noted that basic screening and blood tests might not catch early warning signs of MetALD. "There's a good percentage of patients that will have normal liver enzymes," Arab said.

And in any case, many insurers don't cover comprehensive metabolic panels that would detect strange liver enzymes as part of preventive care. The annual wellness visits covered by Medicare typically don't include the tests, though sometimes doctors can skirt around that problem by indicating the patient has a risk factor for chronic liver disease; however, coverage varies by state and payer.

"The larger issue is that many will have normal liver enzymes and not be appropriately screened and diagnosed with liver fibrosis," said Brian Lee, a transplant hepatologist and researcher at the Keck School of Medicine at the University of Southern California.

Researchers are pushing for the wider adoption of noninvasive tests like the FIB-4 index, which are underused and can quickly assess a patient's liver health.

Typically, doctors want to know if someone's liver is stiffer than it should be, which is an indication that scar tissue has built up. A FIB-4 score can estimate the degree of liver scarring using a patient's age, platelet count, and liver enzyme levels. After that, clinicians can decide if the patient needs further testing with an ultrasound or biopsy.

Given the number of patients diagnosed with liver disease at the end stages, Lee said that "where treatment and ability to reverse disease is more limited," physicians should be trying to catch problems early.