Non-Alcoholic Fatty Liver Disease (NAFLD)
Non-alcoholic fatty liver disease (NAFLD), also called fatty liver disease, is a condition in which fat builds up in the liver, not due to heavy alcohol use.
There are two types of NAFLD:
- Simple fatty liver, in which fat builds up in the liver without inflammation or damage to liver tissue
- Non-alcoholic steatohepatitis (NASH), in which fat buildup is accompanied by liver inflammation and damage to liver tissue, which can cause scarring (fibrosis) and can lead to cirrhosis and liver failure
NAFLD is the most common liver disease in children in the U. S., affecting 5 to 8 million children and adolescents.
Causes
Not all the causes of NAFLD are known at this time but the disease is associated with genetics, dietary intake and obesity; dietary intervention and weight loss are currently the most effective treatments in reducing fat build up in the liver.
NAFLD is more common in children and adolescents who have:
- Obesity
- High levels of cholesterol and triglycerides in the blood
- Insulin resistance
- High blood sugar levels (indicating pre-diabetes or type 2 diabetes)
- High blood pressure
- Certain metabolic disorders, including metabolic syndrome and lipodystrophy
NAFLD is more common in Hispanics and less common in African-Americans. Asian-Americans are more likely than other ethnic groups to develop non-alcoholic fatty liver disease when their weight is within a normal range.
Signs and symptoms
NAFLD can be present without symptoms. When symptoms do occur, they may include discomfort or pain in the upper right side of the abdomen.
In cases of advanced liver disease, when the disease causes damage to the liver, symptoms may include:
- Yellowing of the skin and eyes (jaundice)
- Abdominal swelling (ascites)
- Abnormal bruising
- Chronic fatigue
- Extreme skin itching (pruritus)
- Abnormal brain function (encephalopathy)
- Enlarged spleen
- Enlarged blood vessels under the skin
Testing and diagnosis
Because it so often occurs without symptoms, non-alcoholic fatty liver disease is often flagged for possible diagnosis when routine blood tests show high levels of cholesterol and blood sugar, or when blood tests for liver enzyme levels are done for other reasons. The American Academy of Pediatrics (AAP) recommends screening for NAFLD at ages 9 to 11 for children who are obese or who are overweight and have other risk factors, and earlier if there is a family history of NAFLD.
When non-alcoholic fatty liver disease is suspected, the doctor will do a thorough physical exam and will take a history of the patient’s health and symptoms. Tests used to diagnose NAFLD include:
- Blood tests for liver enzymes, especially alanine aminotransferase (ALT) and aspartate aminotransferase (AST); for other indicators of liver disease; and for indicators of other conditions, such as infection, autoimmune disease, metabolic or genetic disorders
- Ultrasound imaging
- Magnetic resonance (MR) elastography
- Liver biopsy
Treatment
The first line of treatment for NAFLD is weight loss through lifestyle changes, focusing on nutrition and physical activity, and sleep. Research on adults with NAFLD has found that a 10 percent reduction in weight is associated with a 90 percent resolution of the liver disease.
Weight loss can be difficult, and results are better when the patient has frequent contact with doctors, dieticians and exercise therapists with weight management expertise. Goal setting, tracking and incentives can all help motivate a child to adhere to the weight loss program.
When behavior change alone does not work to reduce weight and fat buildup in the liver, medication and, if warranted, bariatric surgery may be considered.
No medicines have been approved to treat NAFLD, but studies are investigating the possible effectiveness of treatment with medication.
Outlook
In all but the most advanced cases, weight loss through diet and exercise reverses non-alcoholic fatty liver disease.
In cases of NASH that advance to cirrhosis and liver failure, liver transplant may be needed.
Follow-up care
Health gains through weight loss must be maintained for life to prevent the recurrence of non-alcoholic fatty liver disease. Patients diagnosed with NAFLD require regular monitoring to check weight and the indicators for the disease. Ongoing support to maintain healthy weight may be needed.
Why choose CHOP?
The medical team in the Non-alcoholic Fatty Liver Disease Clinic at Children’s Hospital of Philadelphia (CHOP) is led by a physician with special expertise in NAFLD, and includes a registered dietician, a physical activity specialist, a psychologist, a nurse and a coordinator.
We work with patients to diagnose NAFLD, then, in monthly meetings with different specialists, to make lifestyle changes, mainly in diet and physical activity, to reduce levels of fat in the body with the goal of eliminating excess fat and inflammation in the liver.
Reviewed by Jennifer Panganiban, MD