Dealing with fatty liver
FATTY livers in geese are prized, but in humans, they can cause serious health complications.
A whopping 30% of the AsiaPacific population is affected by non-alcoholic fatty liver disease (NAFLD) and the numbers are only getting bigger, according to a 2012 study published in Hepatology International.
The same study reported an NAFLD prevalence in Malaysia of 22.7% among individuals attending a health check at a suburban medical facility and observed an inordinately high prevalence of NAFLD among Malays and Indians compared to that of other races.
Most people with fatty liver have simple steatosis or simple fatty liver in which case the fat does not cause inflammation in the liver. People with NAFLD do not consume significant amounts of alcohol.
However, up to 25% of people with NAFLD experience nonalcoholic steatohepatitis (NASH), characterised by inflammation that can lead to fibrosis (scarring), cirrhosis (severely scarred, hardened and shrunken liver), and eventual liver failure, whose only mode of treatment is liver transplantation.
“There is an increasing number of patients with NAFLD who develop liver cancer or require liver transplants. In fact, NASH is now the second most common cause for liver transplants in the United States and will likely overtake hepatitis as the number one cause for liver transplantation in the future, as more hepatitis C patients today are being treated with curative antiviral drugs,” says Dr Ganesalingam Kanagasabai, consultant gastroenterologist at Subang Jaya Medical Centre.
Only a small percentage of NAFLD cases progress to cirrhosis, but it still makes a significant impact on the regional disease burden.
A subtle disease
NAFLD across the board is typically asymptomatic. In rare cases, patients complain of discomfort, but by the time symptoms are noticeable, it is usually too late and the liver has begun failing.
Tangible symptoms include swollen ankles due to fluid retention, jaundice, confusion and internal bleeding.
“The most common way that people find out they have fatty liver is when they undergo an ultrasound scan of the liver or routine blood test that reveals an abnormal reading of liver enzymes,” says Dr Ganesalingam.
According to him, most people with fatty liver have metabolic syndrome – a cluster of conditions that includes hypertension, obesity, diabetes and elevated cholesterol levels.
The danger zone
“People with fatty liver don’t often die from liver disease. The majority instead succumb to cardiovascular complications or stroke caused by metabolic syndrome, which is associated with fatty liver,” says Dr Ganesalingam.
“Cancer-related deaths are among the top three causes of death in people with NAFLD.”
He states that for the average person, liver disease is the 12th most likely cause of death. For someone with fatty liver, however, the likelihood of liver disease killing him goes up to third place.
Detecting the culprit
A fatty liver is any liver with more than 5% fat. Currently, only livers with a significant amount of fat can be picked up through ultrasounds.
The drawback with ultrasounds is that if the scarring is not severe, the radiologist will be unable to tell if the liver is damaged.
“The difficult part is detecting which patient with fatty liver has NASH with ongoing inflammation and scarring in the liver. A patient can have normal liver test results yet have significant inflammation and scarring,” says Dr Ganesalingam.
According to him, the most accurate way to test for NASH is to do a liver biopsy – an invasive procedure with potential risks.
The diagnostic timeline
“When a patient is diagnosed with NAFLD, the next course of action is to examine his risk potential and determine contributing factors such as diabetes, high blood pressure, obesity, high cholesterol, smoking and lack of exercise. After that, we have to assess whether the fat is causing the liver harm,” says Dr Ganesalingam.
A non-invasive, quick and simple way of assessing whether or not the fatty liver is harmful is with a transient elastography of the liver that can determine the degree of fibrosis and the amount of fat in the liver. A transient elastography is performed with a Fibroscan machine.
“The Fibroscan uses shear waves that are projected at the liver. The rate at which they travel through the liver is measured.
“If there is significant scarring within the liver due to fat-induced inflammation, the waves travel faster through the denser tissue and results in a higher reading,” says Dr Ganesalingam.
A Fibroscan is useful in assessing the seriousness of fatty liver cases, but is unfortunately not widely available in Malaysia.
A low transient elastography reading indicates simple fatty liver with no scarring. A high reading is cause for concern as these patients probably have NASH and an increased risk of cirrhosis, liver failure or liver cancer.
Patients with high readings need to be monitored for potential complications due to their fatty liver. It is believed today that patients previously thought to have cirrhosis of unknown cause (called cryptogenic cirrhosis) probably had NASH.
Treatment and prevention
Lifestyle intervention consisting of diet adjustments, exercise and weight loss is the cornerstone of treatment for fatty livers. It is advisable to aim for at least 5% weight loss, but the recommended rate is around 7% to 10%.
According to Dr Ganesalingam, it is generally believed that a 10% weight loss leads to as much as 80% reduction of liver fat, which in turn reduces inflammation and can reverse scarring in the liver.
If a patient loses more than 5% of his total weight, a significant amount of fat, inflammation and scarring in the liver is reduced. Equal emphasis should be given to proper control of diabetes, blood pressure and cholesterol levels.
Other strategies involve drug treatment. Non-diabetic NASH patients with significant liver scarring are prescribed vitamin E, while diabetic NASH patients are prescribed pioglitazone.
More new drugs emerge every day, but even promising ones such as the glucagon-like peptide-1 receptor agonist are still in testing or trial stages, which means the only treatment for NAFLD is still lifestyle intervention. In patients who are morbidly obese where lifestyle intervention has failed, bariatric surgery is an option.
“A medical consultation for NAFLD should emphasise lifestyle intervention consisting of diet change, exercise and weight loss. It is important to remember that most patients with NAFLD die from heart disease and stroke, not liver disease.
“It is futile to take a liver supplement diligently without watching your diet, exercising and quitting smoking. Liver supplements should not be used as the cure-all for NAFLD,” adds Dr Ganesalingam.
A transient elastography is used to diagnose liver trouble.