From the Guidelines
An enlarged liver does not always indicate a fatty liver, as various conditions can cause hepatomegaly, including viral hepatitis, alcoholic liver disease, and genetic disorders. According to the American College of Radiology 1, hepatocellular injury can cause the release of ALT and AST in serum, and an increase in ALT is directly linked to hepatocyte injury, which can be caused by conditions other than fatty liver disease, such as acute or chronic viral hepatitis, autoimmune hepatitis, and hemochromatosis.
Some key points to consider when evaluating an enlarged liver include:
- The causes of mild increases in aminotransferases are nonalcoholic fatty liver disease (NAFLD) and alcohol-induced liver disease, but uncommon causes like drug-induced liver injury, hepatitis B, and hereditary hemochromatosis should also be considered 1.
- The AST:ALT ratio can help differentiate between alcohol-induced fatty liver disease and metabolic disease-related fatty liver, with a ratio generally >2 in alcohol-induced fatty liver disease and <1 in metabolic disease-related fatty liver 1.
- NAFLD is a spectrum of fat deposition and hepatic inflammation followed by fibrosis due to metabolic insults, and simple hepatic steatosis can be seen in 70% to 75% of cases without cellular insult 1.
When a healthcare provider detects an enlarged liver, they typically order additional tests to determine the underlying cause, including blood tests to check liver function, imaging studies like ultrasound, CT, or MRI, and sometimes a liver biopsy 1. The treatment approach depends entirely on identifying the specific cause of the enlargement, and addressing the underlying condition often allows the liver to return to normal size and function, particularly if diagnosed and treated early before permanent damage occurs.
From the Research
Definition of Fatty Liver Disease
- Metabolic dysfunction-associated fatty liver disease (MAFLD) is a condition characterized by the accumulation of excess fat in the liver, often associated with metabolic abnormalities such as insulin resistance and obesity 2.
- The diagnosis of MAFLD does not require the exclusion of secondary causes of liver disease or alcohol consumption, which means that MAFLD can coexist with other types of liver diseases, such as viral hepatitis 2.
Enlarged Liver and Fatty Liver Disease
- An enlarged liver, also known as hepatomegaly, can be caused by various conditions, including fatty liver disease, viral hepatitis, and other liver diseases 3, 4.
- However, not all cases of enlarged liver are due to fatty liver disease, as other conditions such as viral hepatitis, alcohol-related liver disease, and other liver diseases can also cause hepatomegaly 4, 5.
Relationship between Fatty Liver Disease and Viral Hepatitis
- Fatty liver disease can coexist with viral hepatitis, and the presence of MAFLD can alter the disease course and management of viral hepatitis 3, 2, 4.
- The interaction between MAFLD and viral hepatitis is complex, and the impact of MAFLD on the progression of liver disease and treatment outcomes in patients with chronic viral hepatitis is still being studied 3, 2, 4.
Diagnosis and Management
- The diagnosis of MAFLD and viral hepatitis requires a comprehensive approach, including laboratory tests, imaging studies, and liver biopsy 2, 4.
- Management of MAFLD and viral hepatitis involves a multidisciplinary approach, including lifestyle modifications, antiviral therapy, and treatment of metabolic abnormalities 3, 2, 5.