Fatty liver disease affects 45% of teens, adults in US, Hispanics most
Analysis follows changes in nomenclature with 2023 update
About 45% of teens and adults in the U.S. have some form of fatty liver disease, with Hispanic populations being more affected than other racial and ethnic groups, a study indicates.
The analysis was conducted using the new nomenclature for fatty liver disease and its types that came under a 2023 update.
Risk factors for metabolic dysfunction-associated steatotic liver disease (MASLD), a common form of fatty liver disease that was present in 42% of the participants, included being Hispanic, male, older, and having certain cardiometabolic risk factors. Other forms of fatty liver disease — including that associated with alcohol misuse — were less common, together affecting little more than 2% of people. Researchers believe their frequency could be underestimated, however.
“This study highlights a significant health issue that affects a large portion of the U.S. population, and it shows that certain groups are at a higher risk,” Juan Pablo Arab, MD, the study’s senior author at Virginia Commonwealth University, said in a university news story. “We hope these findings will guide more targeted health interventions to reduce the burden of liver disease, especially in high-risk communities.”
The study, “Disparities in steatosis prevalence in the United States by Race or Ethnicity according to the 2023 criteria,” was published in Communications Medicine.
Fatty liver disease refers to a group of conditions marked by abnormal amounts of fat in the liver. It was traditionally divided into two main types, where alcoholic fatty liver disease (AFLD) occurred in the context of high alcohol consumption and nonalcoholic fatty liver (NAFLD) encompassed any other cases.
Assessing prevalence of fatty liver disease
The nomenclature for fatty liver disease and its types was updated in 2023 with new diagnostic criteria to more accurately reflect the underlying cause of disease and to be less stigmatizing. Fatty liver disease became steatotic liver disease (SLD) and AFLD became alcohol-associated liver disease (ALD). Most cases previously considered NAFLD are now classified as MASLD, where fatty liver occurs in the presence of cardiometabolic risk factors such as type 2 diabetes, obesity, or elevations in blood sugar, blood pressure, or fats in the blood.
While MASLD usually doesn’t cause any overt health problems, left unaddressed it can progress to cause inflammation and tissue scarring (fibrosis) that damage the liver. This severe form, previously called nonalcoholic steatohepatitis (NASH), is now known as metabolic dysfunction-associated steatohepatitis, or MASH.
The new nomenclature also includes an additional type of SLD called metabolic dysfunction and alcohol-associated liver disease (MetALD), where a person meets the criteria for both MASLD and ALD.
Here, the scientists assessed the prevalence of the various forms of SLD under the new nomenclature among 5,532 people in the U.S., ages 15 and older, who participated in the National Health and Nutrition Examination Survey between 2017-2018. The participants (50.9% women) had a mean age of 45.4 and more than 45% of were found to have SLD. As expected, MASLD was the most common type, affecting an estimated 42.4% of the evaluated population. MetALD and ALD affected 1.7% and 0.6% of the participants, respectively.
Risk factors for fatty liver disease
MASLD rates were highest in Hispanic people, affecting 47% of that group. That’s a substantial increase from a 2014 study that found a MASLD prevalence of 29% among Hispanics. Certain genetic factors and higher rates of risk factors such as diabetes and obesity may account for why Hispanics may be more prone to MASLD.
Black people had the lowest risk of developing MASLD relative to other racial/ethnic groups.
Statistical analyses adjusted for potential influencing factors showed that, in addition to Hispanics, men, adults older than 40, people with health insurance, and those with risk factors including a high body mass index (BMI; a ratio between height and weight), diabetes, high blood pressure, or altered fat levels in the blood had a higher risk of MASLD.
Risk factors for MetALD included being male and having a higher BMI, while being Asian appeared to be a protective factor. Having health insurance was significantly associated with a lower risk of ALD.
While MASLD was more prevalent in Hispanics, there were no differences in the rate of advanced liver fibrosis or MASH between racial/ethnic groups.
Metabolic risk factors, including excessive weight, abnormal blood sugar metabolism, and high blood pressure, were significantly associated with an increased risk of advanced fibrosis.
The “results highlight the importance of targeted prevention efforts in people with a higher risk of developing liver disease,” the researchers wrote. “Future public health strategies should focus on reducing risk factors and providing equitable healthcare access.”
Accurately diagnosing MetALD and ALD isn’t always easy, so the conditions may be more prevalent than is estimated, said the researchers, who noted that studies that follow people over time and utilize “precise alcohol use quantification, including standardized assessments and alcohol biomarkers, are necessary to better estimate the burden of MetALD and ALD.”
About the Author
