They are young, hardly touch alcohol, and are neither obese nor diabetic, but still diagnosed with fatty liver disease. What is happening?

 

Non-alcoholic fatty liver disease has lately become a cause for concern in the medical community here because of the rising incidence and changing demographics.

 

In the last decade, the incidence has risen to almost 50 per cent of the adult population. Those diagnosed with fatty liver disease do not fit the usual profile of patients who have known risk factors – heavy alcohol drinkers, or those who are obese or diabetic.

 

New data shows that people without these conditions are now developing the disease. Some are in their 20s and of average weight and appearance, and have one common characteristic – they either drink very little alcohol or none at all. “It’s difficult to know who has this disease without scanning their liver,” said Professor Pierce Chow, Senior Consultant, Division of Surgical Oncology, National Cancer Centre Singapore (NCCS), who has been leading research on the disease and its relationship to liver cancer.

 

 

Fatty liver is defined as a liver with at least 5 per cent fat in its cell content, which can be detected through a biopsy or by MRI , CT or ultrasound scan. However, an ultrasound scan can only pick up a fatty liver when the liver has at least 30 per cent fat.

 

If caught early, and before the inflamed liver has developed scarring or cirrhosis, the disease can be reversed. But once it becomes cirrhotic, the disease is irreversible because liver cells have been replaced by scar tissue, making the organ progressively dysfunctional. Cirrhosis of the liver also puts a person at risk of developing liver cancer.

 

Another concern is that the simple form of the disease can progress to non-alcoholic steatohepatitis, a more severe and complicated form of fatty liver.

 

An even more troubling trend has emerged, said Prof Chow. Patients with non-alcoholic fatty liver disease are increasingly observed to bypass this non-alcoholic steatohepatitis stage and cirrhosis, and develop liver cancer.

 

 

“This has been noted by a number of international centres, including NCCS, and we are increasingly concerned about it. Global statistics project that in the next 10 to 15 years, non-alcoholic fatty liver disease will be the main cause of liver cancer around the world, surpassing even Hepatitis B and C, which are currently the number one causes,” he said.

 

The rising incidence of non-alcoholic fatty liver disease in Singapore is consistent with the rest of the developed world. In the US, non-alcoholic steatohepatitis is the second cause of patients needing a liver transplant. “The epidemiological data is strong but the mechanisms are unclear,” said Prof Chow.

 

The high incidence rate here was detected by one of Prof Chow’s medical students, Mr Kevin Khaw from Duke-NUS Graduate Medical School.

 

“While attached to the ward and clinic, he noticed from looking at scans that a significant number of patients admitted for gallbladder surgery had non-alcoholic fatty liver disease. He realised that the incidence was higher than expected, so he did a comparison study,” said Prof Chow. The results (which won Mr Khaw a prize at a scientific conference) were staggering. Between 2000 and 2003, only 30 per cent of patients with gallstone disease had concomitant fatty liver disease. A decade later, between 2010 and 2013, the figure was 50 per cent.

 

“These are patients who came to consult me for gallstone disease, not liver disease, but our routine scans showed they also had fatty liver,” said Prof Chow.