Fatty liver is an extremely common condition that affects about 25% of all adults. Fatty liver is usually detected on a routine abdominal ultrasound scan. Sometimes apparently healthy individuals are detected to have mild abnormalities in the blood tests related to the liver and on further evaluation with an ultrasound scan, they are detected to have fatty liver. Fatty liver can affect both people who drink alcohol and those who do not drink. Once excess alcohol consumption is excluded, fatty liver is usually related to a condition called metabolic syndrome wherein an individual usually is overweight and suffers from diabetes, has high blood pressure, cholesterol and triglycerides.
Fatty liver is of two types. The first type is simple fatty liver, also known as NAFL (non-alcoholic fatty liver). NAFL does not usually progress to more advanced forms of liver disease. The second type of fatty liver is known as NASH (non-alcoholic steatohepatitis). NASH is the progressive form of fatty liver and leads to liver fibrosis and eventually to end stage liver disease or cirrhosis. Therefore, it is not enough to diagnose just fatty liver. Once an individual is detected to have fatty liver, it is essential to diagnose whether he has NAFL or NASH. The only way to conclusively differentiate between these two forms of fatty liver is a liver biopsy.
Patients with fatty liver may have normal blood tests or just mild elevations of liver enzymes called AST and ALT. However, the degree of elevation of liver enzymes is not correlated with the severity of fatty liver. It is important to understand that one should not rely on liver enzyme elevation to differentiate between NAFL and NASH. To put is simply, a person with fatty liver cannot feel reassured that his liver is normal if the liver enzymes are normal.
Fibroscan is a technology that can determine the amount of liver damage without actually doing a liver biopsy. An important use of Fibroscan is to detect whether a person suffering from Fatty Liver has the simple form of fatty liver or the progressive form (NASH). Fibroscan is a simple procedure that can be done in the clinic using a special ultrasound machine. Fibroscan actually detects the firmness of the liver. The Fibroscan machine shoots an ultrasound wave into the liver and then estimates the speed at which the wave travels in the liver and is reflected back. Normal livers are soft while diseased livers are firm to hard. The firmer the liver, the more diseased it is. Patients with fatty liver who are detected to have firm livers on Fibroscan need close medical supervision, monitored weight loss, rigorous control of co-morbid factors and specific medications. Several new drugs that have a potential role in reversal of early liver fibrosis are in advanced trials. On the other hand, individuals with a soft liver on Fibroscan can be reassured and other tests including a liver biopsy can be avoided.
Fibroscan is now a standard recommendation in evaluation of patients with fatty liver. It is the only non-invasive test that stratifies risk in these patients. It also helps in following up patients once they are on treatment to assess whether liver is improving or not. Fibroscan can also be done for any other chronic liver disease such as hepatitis B, hepatitis C, or alcoholic liver disease, where it can assess the stage of the liver disease in a non-invasive manner.