Non-Alcoholic Fatty Liver Disease (NAFLD)
NAFLD is an increasingly common chronic disease of the liver. This condition occurs in patients who have developed fat in their liver (steatosis) and in patients who have developed a chronic inflammation or scarring of the liver (fibrosis). The presence of both fat and fibrosis in the liver is called nonalcoholic steatohepatitis (NASH). NAFLD has been reported to be present in around 45% of the U.S. population, while NASH is seen in 5%. NAFLD is especially more common in patients who also have been diagnosed with diabetes, obesity and high cholesterol. NAFLD does not present with any typical symptoms as it’s usually discovered incidentally in patients with elevated liver function tests or through imaging tests done for other reasons. The most common imaging test is an abdominal ultrasound, while an MRI is the most accurate imaging test to detect NAFLD. Until recently, the only way to both diagnose and assess the severity of liver fibrosis was through a liver biopsy. However, there is a new type of ultrasound called a liver elastrography that uses sound waves against the liver to accurately determine the extent of liver fibrosis. In addition, there are blood tests such as the Fibrosure test that can accurately calculate a fibrosis score.
The diagnosis of NASH is important because if untreated it can lead to major complications including hepatocellular carcinoma, liver cirrhosis and possible death. The main lifestyle modifications to treat NASH include aggressive weight loss and avoiding both alcohol and medications that can be toxic to the liver (such as excessive amounts of Tylenol). The main option in terms of medical treatment is vitamin E which works to decrease the inflammation caused by the presence of fat in the liver. For patients with both diabetes and NASH, the treatment of choice is a class of diabetes drugs called thiazolidinediones. Excess weight loss remains far superior to medications in treating NASH. In fact, many patients are cured from NASH after having weight loss surgery such as a gastric bypass. Since obesity is likely to become even more common in the future, there is no doubt that NASH and its complications will become increasingly problematic as well.