Also known as steatotic liver disease, fatty liver disease occurs when too much fat accumulates in the liver. In some people, it can lead to long-term liver damage. Steatotic liver disease is also linked with heart disease.
Causes of Steatotic Liver Disease
Experts are unsure what exactly causes steatotic liver disease, but associated factors include obesity, diabetes, high blood pressure and high cholesterol.
"Steatotic liver disease is a major and increasingly prevalent condition that is likely an underlying precursor to many conditions, including those involving the heart," said Susan Cheng, MD, MPH, director of the Institute for Research on Healthy Aging in the Department of Cardiology in the Smidt Heart Institute and lead author of the study. "We are paying even more attention to steatotic liver disease because we are seeing how it tracks closely with established cardiovascular risk factors such as hypertension, high cholesterol and diabetes."
Medical experts recently created new terms to classify the different types of steatotic liver disease:
- metabolic dysfunction-associated steatotic liver disease (MASLD)
- alcohol-related liver disease (ALD)
- metabolic dysfunction-associated and alcohol-related liver disease (MetALD)
Affects Women Differently
Cedars-Sinai investigators sought to learn how these types of steatotic liver disease may affect men and women differently.
The investigators analyzed data from 1988 to 1994 collected through the National Health and Nutrition Examination Survey III. Study participants completed questionnaires and underwent medical exams and laboratory tests, which included providing information on alcohol use, cardiometabolic risk factors, and undergoing imaging scans of the liver.
The investigators identified more than 10,000 people age 21 and older living in the U.S. who had data available from the liver scans and other medical exams.
Increased Risk of Dying
Nearly one-fifth of the whole cohort, totaling 1,971 people, had steatotic liver disease, and more than 75 percent of these adults had MetALD. Although all forms of steatotic liver disease were about twice as common in men than women, the data showed that risk of death was significantly higher in women over a median period of 26.7 years.
For example, having MetALD increased risk of dying 83 percent more in women than in men, when compared with people who did not have liver disease. Even further, women with ALD had a 160 percent greater mortality risk than men with ALD.
"These findings are especially concerning in the context of the COVID-19 pandemic, during which alcohol use and related death, particularly in women, has increased," said Alan Kwan, MD, a research instructor in the Department of Cardiology at Cedars-Sinai who also worked on the study.
Be Cautious About Drinking
Being overweight or obese, having prediabetes or diabetes, high blood pressure, or abnormal cholesterol levels in the blood could be signs of underlying metabolic liver disease. Women with these risk factors should be especially cautious about excess alcohol intake, according to the investigators.
The Centers for Disease Control and Prevention defines moderate drinking for women as one drink or less a day.
The investigators plan to continue to study why the female liver is more affected by alcohol than the male liver and what lifestyle changes, in addition to reducing alcohol intake, might reduce a woman's risk for fatty liver disease.
They also point out that because the study analyzed data collected between 1988 and 1994, more studies are needed to learn how the prevalence of liver disease and alcohol use may have changed over time.
Source: Ji, H, et al. "Sex differences in prevalence and prognosis of steatotic liver disease phenotypes: Biological sex matters." Journal of Hepatology 13 August 2023