More than 15m people in UK, US, Germany and France unknowingly have aggressive fatty liver disease – study
New research has found that fewer than 18 per cent of people with metabolic dysfunction-associated steatohepatitis (MASH) across four major Western countries have been diagnosed—leaving millions unaware they have a serious form of fatty liver disease.
MASH is the most severe form of metabolic dysfunction-associated steatotic liver disease (MASLD)—a condition that occurs in people who drink little or no alcohol and have more than 5 per cent fat in their liver.
It causes liver scarring that can progress to cirrhosis and is linked to higher risks of cardiovascular disease, chronic kidney disease, and liver cancer.
The study looked at data from the US, UK, Germany and France.
It found that just under 3 per cent of people in the UK, France and Germany, and 4 per cent in the US, are living with MASH. Yet most remain undiagnosed.
Researchers estimate that around 20 million people across the four countries have the condition, but only 2.5 million have received a diagnosis—meaning more than three-quarters, or about 16.7 million people, are unaware they have it.
The report calls for diagnosis rates to double from 2022 levels. While MASH was traditionally diagnosed using biopsies, non-invasive tools such as blood tests, ultrasound and MRI scans are now widely available, making screening more accessible.
The researchers recommend screening for everyone with type 2 diabetes, individuals with obesity and at least one additional risk factor, and those with persistently elevated liver enzymes.
Dr Jeffrey Lazarus is lead author of the paper and professor of global health in New York and Barcelona.
The researcher said: “Undiagnosed MASH costs economies billions of pounds in lost productivity and poor health.
“Unless diagnosis rates are doubled, alongside similar increases in treatment and care, direct health costs alone are predicted to triple over the next 20 years.”
The research has also prompted renewed calls for the use of weight loss medications to treat MASH.
Dr Paul Brennan, co-author and hepatologist at NHS Tayside, said: “GLP-1s (including Wegovy and Mounjaro) offer the potential to resynchronise our metabolism, by introducing feelings of satiety – fullness – and delaying the time the stomach takes to empty.
These effects often result in reduced calorie intake, and improvements in how the liver handles nutrients as a result of weight loss, thus reducing scar tissue formation in the liver.”
Professor Emmanouil Tsochatzis, professor of hepatology at University College London and consultant hepatologist at the Royal Free hospital, added: “More than 15 million people across the US and Europe have the deadliest form of fatty liver disease – and don’t know it.
“Without faster diagnosis and access to treatment, the human and economic toll will skyrocket.”
