Children's Hospital Colorado

Non-Alcoholic Fatty Liver Disease (NAFLD)

What is a non-alcoholic fatty liver disease (NAFLD)?

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in the United States. Sometimes referred to as "fatty liver disease," it is actually a range of diseases that all begin when excess fat gets deposited in the liver.

As the disease becomes more severe, inflammation or irritation of the liver occurs and then scar tissue (fibrosis) develops. The disease is then referred to as NASH (non-alcoholic steatohepatitis).

If the scar tissue is extensive, cirrhosis develops and the liver may function poorly.

The exact cause(s) of NAFLD is currently unknown. It is likely a combination of several factors, including a genetic background that puts children at higher risk of the disease combined with environmental triggers that can cause insulin resistance and pre-diabetes and the accumulation of specific fats in the liver.

Once the process begins, activation of the immune system and oxidative likely cause ongoing damage.

Who gets non-alcoholic fatty liver disease?

NAFLD affects approximately 30 million people, 8.6 million of whom have the more severe form of the disease, NASH. NAFLD affects almost 10% of all children in the United States.

Approximately 1% of 2 to 4 year olds and 17% of 15 to 19 year olds have NAFLD. In addition, 38% of obese children have NAFLD. Among adults, NAFLD has become a leading cause for liver transplant. Children, who will live the longest time with the disease, are at particular risk of complications and poor prognosis, including the need for liver transplant in adulthood.

Most children with NAFLD are in their early adolescent years. NAFLD, however, is being increasingly observed in young children. Males are affected twice as often as females and Hispanics are more likely to develop NAFLD than non-Hispanics, whites or Blacks. Obese children are at the greatest risk for developing NAFLD. In addition, having type 2 diabetes or pre-diabetes, the metabolic syndrome, or high blood lipids increases the risk of developing NAFLD.