April 14, 2016, Barcelona, Spain: Researchers today demonstrated that a scoring system can predict a person's risk of death from non-alcoholic fatty liver disease (NAFLD), the world's most prevalent liver disease. The study results were presented today at The International Liver CongressTM 2016 in Barcelona, Spain.
It is known that those with severe NAFLD have an increased risk of death, but precisely identifying a patient's risk of mortality has previously proved challenging for clinicians. The SAF score was developed to more accurately predict the severity of NAFLD. SAF, or steatosis (accumulation of fat in the liver cells), activity, and fibrosis (thickening or scarring of connective tissue in the liver as a response to damage) are three measures of liver function and the researchers found that a higher score is associated with increased mortality.1
"We suspected that steatosis, activity and fibrosis were important to overall risk but we wanted to validate their impact on mortality over a long-term follow-up period through a validated and simple scoring system," said Dr Hannes Hagström, fellow of the Department of Gastroenterology and Hepatology at Karolinska University Hospital, Stockholm and lead study author. "This new analysis is vital in showing the link between severe non-alcoholic fatty liver disease and mortality, which is an important measure given that this is the most common liver disease worldwide."
The researchers used data from 139 patients with biopsy-proven NAFLD. All of the biopsies were re-classified according to the SAF scoring system, with the diseases defined as mild, moderate or severe via an index combining activity and fibrosis. Further data on overall mortality was taken from a national population register. A Cox regression model, adjusted to take into account body mass index and the presence of type 2 diabetes, was used to examine the predictive value of the SAF score. Patients were followed up for an average of 26 years (standard deviation 6.1, range 1.7 – 40.8 years).
At baseline, 69 patients had a severe form of the disease and 35 patients had mild or moderate disease. Of the 70 patients who died during follow-up, 59% came from those previously classified as having a severe form of NAFLD.
"This long-term study demonstrates the importance of having sufficient follow-up periods for patients with NAFLD," said Professor Laurent Castera, EASL Secretary General. "This is an important step forward for the medical community in being able to identify the patients who are at most risk of death from the disease."
Non-Alcoholic Fatty Liver Disease
In NAFLD, fat builds up in the liver, in some cases causing inflammation that can lead to permanent scarring (cirrhosis) which impairs liver function. NAFLD can occur in people who drink no alcohol or in moderation, and is closely associated with obesity and diabetes.2 Guidelines published by the World Gastroenterology Organisation suggest that the prevalence of NAFLD has doubled over the last 20 years, and it now affects more than 20% of the worldwide population.1
Cox regression model
The Cox regression model is a statistical technique for exploring the relationship between the survival of a patient and several explanatory variables. The model provides an estimate of the treatment effect on survival after the adjustment of other explanatory variables. The final model will yield an equation for the hazard as a function of several explanatory variables.3
About The International Liver Congress™
This annual congress is the biggest event in the EASL calendar, attracting scientific and medical experts from around the world to learn about the latest in liver research. Attending specialists present, share, debate and conclude on the latest science and research in hepatology, working to enhance the treatment and management of liver disease in clinical practice. This year, the congress is expected to attract approximately 10,000 delegates from all corners of the globe. The International Liver Congress™ takes place from April 13 – 17, 2016, at the Fira Barcelona Gran Via, Barcelona, Spain.
Since EASL's foundation in 1966, this not-for-profit organisation has grown to over 4,000 members from all over the world, including many of the leading hepatologists in Europe and beyond. EASL is the leading liver association in Europe, having evolved into a major European Association with international influence, with an impressive track record in promoting research in liver disease, supporting wider education and promoting changes in European liver policy.
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Onsite location reference
General session 1 and opening, Hall 6.0
Thursday 14 April, 14:00 – 15:30
Presenter: Hannes Hagström, Sweden
Abstract: GS05, SAF Score as a marker for mortality in NAFLD after up to 41 years of follow-up
Author disclosures of interest
1 World Gastroenterology Organisation Global Guidelines. Non-alcoholic Fatty Liver Disease and Non-alcoholic Steatohepatitis. Available from: http://www.worldgastroenterology.org/assets/export/userfiles/2012_NASH%20and%20NAFLD_Final_long.pdf. Last accessed: March 2016.
2 Sattar N, et al. Non-alcoholic fatty liver disease. Available from: http://www.bmj.com/content/349/bmj.g4596. Last accessed: March 2016.
3 University of Oxford Medical Sciences Division. What is a Cox model? Available from: http://www.medicine.ox.ac.uk/bandolier/painres/download/whatis/cox_model.pdf. Last accessed: March 2016.
ILC Press office