Fatty Liver Disease

By Francis W. Chan, MD

What is fatty liver disease?

As the name suggests, fatty liver disease is the condition of having fat deposition in the liver. There are two primary types of fatty liver disease – alcoholic fatty liver disease and non-alcoholic fatty liver disease. In alcoholic fatty liver disease, chronic ingestion of alcohol can cause increased fat deposition in the liver. In non-alcoholic fatty liver disease, fat spontaneously deposits into the liver tissue. Just as fat can deposit in many places throughout the body, it can also deposit in the liver.

In most people, fat deposition is harmless. This is called non-alcoholic fatty liver (NAFL). However, in others the presence of fat in the liver triggers an inflammatory response within the liver that, if left untreated, can cause damage to the liver over the course of many years. This is called non-alcoholic steatohepatitis (NASH).

Who develops non-alcoholic fatty liver disease (NAFLD)?

Anyone can develop NAFLD. However, there are certain risk factors that put people at greater risk of developing NAFLD. One of the most significant risk factors is obesity, defined as having a body mass index (BMI) of 30 or greater. There has been an increase in global obesity over the past decade. It is estimated that approximately 35% of the U.S. adult population is obese. The rates of obesity in children and adolescents have also been increasing as well. Due to this global trend of increasing rates of obesity, the rate of NAFLD has also been increasing. Other risk factors for NAFLD include diabetes, high blood pressure, and high cholesterol.

How do I know if I have NAFLD?

Oftentimes, an evaluation for NAFLD is initiated after routine labs ordered by your primary care provider reveal an elevation in liver function tests. Findings of fatty liver can also sometimes be incidentally seen on an abdominal ultrasound or CT scan performed for other reasons. The diagnosis of NAFLD is ultimately made by taking a detailed history and exam, and blood tests to exclude other underlying chronic liver diseases. Less commonly, a liver biopsy can obtained.

Can NAFLD be treated?

The primary goal of treatment is weight loss achieved through targeted lifestyle changes that help promote increased physical activity and dietary modification. Management of blood sugar levels and cholesterol are also important interventions.