Health

Surprising study reveals what really kills fatty liver disease patients

More than a third of the world's population is affected by metabolic dysfunction-associated steatotic liver disease, or MASLD, the most common chronic liver disease in the world.

MASLD occurs when fat builds up in the liver and is associated with one or more of five conditions: obesity, Type 2 diabetes, high blood pressure, high blood sugar and low HDL cholesterol, known as "good" cholesterol. These conditions are characterized as cardiometabolic risk factors because they affect the heart or metabolism.

MASLD can lead to serious illness, such as advanced liver, heart and kidney disease, but little research has been done to examine if certain cardiometabolic risk factors for those with MASLD are more associated with death than others.

The deadliest cardiometabolic risk factors

Now, a new study from Keck Medicine of USC published in Clinical Gastroenterology and Hepatology reveals that three of the cardiometabolic risk factors carry the greatest risk of death for those with MASLD: high blood pressure, pre-diabetes or Type 2 diabetes, and low HDL, which raise the risk of death by 40%, 25% and 15%, respectively.

These results were independent of how many or which combination of cardiometabolic risk factors patients had, and held steady despite individuals' gender, sex, race or ethnicity.

"MASLD is a complicated disease, and this study sheds new light on where doctors may want to focus their efforts when treating patients," said Norah A. Terrault, MD, a hepatologist with Keck Medicine and a senior author of the study. "Knowing which aspects of MASLD might lead to poorer outcomes can help us offer patients the best possible care."

Researchers were especially surprised to discover that high blood pressure was associated with a higher chance of death than diabetes, said Matthew Dukewich, MD, PharmD, MS, a USC transplant hepatology fellow and lead author of the study. "Until now, it was commonly thought that diabetes was the most pressing health problem for MASLD patients, which is a key insight."

The study also found that obesity, the most common cardiometabolic risk factor of MASLD, can substantially raise the risk of mortality depending on a patient's body mass index (BMI), which is a formula used to estimate body fat percentage based on an individual's height and weight. The higher a patient's BMI, the higher the association with death.

Additionally, the research adds to the growing body of research that patients with more cardiometabolic risk factors have poorer outcomes. The study found that the risk of death in MASLD patients increased by 15% for each additional cardiometabolic risk factor present.

How the study was conducted

Researchers used data from the National Health and Nutrition Examination Survey (NHANES), which collected health information about children and adults in the United States from 1988-2018, the most current year for which data was available for their study. Out of 134,515 participants 20 years or older, some 21,000 patients qualified as having MASLD.

The study authors tracked all-cause mortality rates by individual cardiometabolic risk factors to reach their conclusions.

Looking ahead, the study authors hope to conduct further studies examining patients' genetic background, dietary habits and alcohol use in relation to MASLD outcomes to provide more comprehensive risk profiles. "The more we can understand about the drivers of the disease, the more we can identify those most in need of interventions and prioritize our resources for enhanced outcomes," said Terrault.

Liyun Yuan, MD, a transplant hepatologist with Keck Medicine, is also a study author.

How the government shutdown is hitting the health care system – and what the battle over ACA subsidies means

Major rifts over key health care issues ^[1] are at the heart of the federal government shutdown that began at the stroke of midnight on Oct. 1, 2025 ^[2].

This is not the first time political arguments over health care policy have instigated a government shutdown. In 2013, for example, the government shut down due to disputes over the Affordable Care Act ^[3].

This time around, the ACA continues to play a central role, with...

The invisible chemical in the air that could be raising Parkinson’s risk

Long-term exposure to a common industrial chemical may be linked to a higher risk of Parkinson's disease.
Trichloroethylene (TCE) is a chemical used in metal degreasing and dry cleaning. Even though it has been banned for some uses, it remains in use today as an industrial solvent and lingers in air, soil and water across the U.S.
Researchers estimated long-term TCE exposure for more than 1.1 million older adults by using ZIP+4 codes and air pollution data.
Older adults living in areas with the highest TCE levels in outdoor air had a 10% higher risk of Parkinson's than those in areas with the lowest levels.
The study does not prove TCE causes Parkinson's, but it adds to growing evidence that environmental pollutants may contribute to risk.

Long-term exposure to the industrial solvent trichloroethylene (TCE) outdoors may be linked to an increased risk of Parkinson's disease, according to a large nationwide study published in the October 1, 2025, issue of Neurology, the medical journal of the American Academy of Neurology.

Trichloroethylene is a chemical used in metal degreasing, dry cleaning and other industrial applications. Although TCE has been banned for certain uses, it remains in use today as an industrial solvent and is a persistent environmental pollutant in air, water and soil across the United States. The study does not prove that TCE exposure causes Parkinson's disease, it only shows an association.

"In this nationwide study of older adults, long-term exposure to trichloroethylene in outdoor air was associated with a small but measurable increase in Parkinson's risk," said study author Brittany Krzyzanowski, PhD, of Barrow Neurological Institute in Phoenix. "These findings add to a growing body of evidence that environmental exposures may contribute to Parkinson's disease."

Researchers used Medicare data to identify people over age 67 newly diagnosed with Parkinson's between 2016 and 2018. Each person was compared with five people who did not have the disease. After removing people without home ZIP+4 information, the study included 221,789 people with Parkinson's and over 1.1 million people without the disease.

They mapped exposure to outdoor TCE concentrations using U.S. Environmental Protection Agency data and participants' residential neighborhood based on their ZIP +4 location. Air levels of TCE were estimated by U.S. Census tract, a small area within a county. Each participant's exposure was based on their neighborhood two years prior to diagnosis.

Researchers divided participants into 10 groups based on their estimated TCE exposure. Those in the lowest exposure group experienced levels between 0.005 and 0.01 micrograms per cubic meter (μg/m³), while those in the highest group had exposures ranging from 0.14 to 8.66 μg/m³.

After adjusting for other factors that could affect the risk of Parkinson's, including age, smoking history and exposure to fine particulate air pollution, researchers found people exposed to the highest outdoor TCE levels had a 10% increased risk of Parkinson's disease compared to people exposed to the lowest levels.

The researchers also identified several geographic "hot spots" where outdoor TCE levels were highest, particularly in the Rust Belt region of the U.S. and smaller pockets across the country. They then analyzed Parkinson's risk in the 10 miles surrounding the three top TCE-emitting facilities in the U.S. from 2002. For two of the areas, risk was higher closer to the facilities, and at one of those sites, there was a clear increasing incremental risk the closer people lived to the facility.

"While the increased risk was modest, the sheer number of people exposed to TCE in the environment means the potential public health impact could be substantial," said Krzyzanowski. "This underscores the need for stronger regulations and more monitoring of industrial pollutants."

A limitation of the study is that it focused only on Medicare-aged individuals, so findings may not apply to younger people or those with early-onset Parkinson's disease. In addition, TCE exposure estimates were based on outdoor air levels in 2002 and may not reflect individual lifetime or indoor exposures.

The study was supported by the U.S. Department of Defense, the Kemper and Ethel Marley Foundation, Barrow Neurological Foundation and the Moreno Family Foundation.

As an OB-GYN, I see firsthand how misleading statements on acetaminophen leave expectant parents confused, fearful and lacking in options

When President Donald Trump adamantly proclaimed in a press conference on Sept. 22, 2025, that pregnant women should not take Tylenol, I immediately thought about my own experiences during my second labor. While pushing for nearly three hours, I developed an infection in my uterus called chorioamnionitis ^[1], which occurs when bacteria infect the uterus, placenta and sometimes the baby’s bloodstream. I had a fever, and my...

Sidebar

Magazine menu