Metabolic liver disease will affect 1.8 billion people worldwide by 2050, driven by rising obesity and blood sugar levels, a study suggests.
Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is one of the most prevalent and rapidly growing liver conditions globally, according to the research.
There are now 1.3 billion people worldwide living with MASLD, the latest estimates suggest, a 143% increase in just three decades. About one in six people – 16% – are affected.
The findings, from the global burden of diseases, injuries, and risk factors study (GBD), were published in the Lancet Gastroenterology & Hepatology journal.
The condition’s prevalence is projected to climb even higher, primarily driven by global population growth in combination with changes in lifestyle, such as rising obesity and high blood sugar levels.
In 1990, there were about 500 million people living with MASLD, the study found. By 2023, that figure had risen to 1.3 billion. MASLD is projected to affect 1.8 billion people by 2050, a 42% rise from 2023.
The global prevalence rate grew to 14,429 cases per 100,000 people in 2023, representing a 29% increase from 1990.
MASLD was more common in men than women and had the highest prevalence rates in older adults aged between 80 and 84. However, the largest number of people affected were younger – around the ages of 35 to 39 in men and 55 to 59 in women.
High blood sugar was the leading driver of MASLD-related health problems globally, followed by high BMI and smoking, highlighting strong links to type 2 diabetes and obesity.
Some regions, including north Africa and the Middle East, had disproportionately higher rates of MASLD compared with other regions. But there have been sharp increases in numbers of people affected in countries across the world.
In the UK, the prevalence rate increased by a third – 33% – between 1990 and 2023, the biggest rise in western Europe, according to an analysis of the data by the Guardian.
The prevalence rate grew by 30% in Australia and 22% in the United States, the analysis revealed.
The study also found that although more people were developing the disease, the overall impact on health – measured in years lost because of illness or death – was stable.
That suggested that advances in treatment and care were helping people live longer and healthier, and that the increase in the number of cases was mostly happening in the early stages of the disease.
However, the growing number of cases still means that many people are at risk of developing serious complications such as liver cirrhosis or cancer in the future.
MASLD is often linked to being overweight and can usually be treated with lifestyle changes.
It does not usually cause any symptoms, and many people have the condition without realising, according to the NHS in England. It is usually only discovered when a patient has tests for another reason.
Symptoms may include feeling very tired, feeling generally unwell, and liver pain or discomfort, which is felt in the abdomen under the right side of the ribs.
The study was led by the Institute for Health Metrics and Evaluation, a public health research institute at the University of Washington in Seattle.
Its authors said the findings highlighted that MASLD was increasingly affecting younger adults, amid worsening health and lifestyles.
The rise in the number of cases underscored the importance of recognising it as a global health priority and of developing policies, awareness campaigns and interventions to mitigate its growing impact and prevent future complications, they said.
