Symptoms & Causes of NAFLD & NASH in Children

What are the symptoms of NAFLD in children?

Usually, nonalcoholic fatty liver disease (NAFLD)—including nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH)—is a silent disease with few or no symptoms. Children may not have symptoms even if they develop cirrhosis due to NASH.

Once symptoms arise, however, a child may already have permanent liver damage. If children do have symptoms from NASH, they may feel tired, become tired easily, or have discomfort over the liver, in the upper right side of the abdomen.

What causes NAFLD in children?

Experts are still studying the causes of NAFLD. Research suggests that certain health problems, genes, and other factors may make some children more likely to develop NAFLD.

Health problems

Children with the following health problems are more likely to develop NAFLD

• overweight or obesity.
• insulin resistance or type 2 diabetes.
• high blood pressure.
• abnormal levels of fats in the blood, which may include
  • high levels of triglycerides.
  • abnormal levels of cholesterol—typically high total cholesterol, high LDL cholesterol, or low HDL cholesterol.
• metabolic syndrome, or one or more traits of metabolic syndrome. Metabolic syndrome is a group of traits and medical conditions linked to overweight and obesity. Doctors typically define metabolic syndrome in children as a combination of three or more of the following features
  • large waist size.
  • high levels of triglycerides in the blood.
  • low levels of HDL cholesterol in the blood.
  • high blood pressure.
  • higher-than-normal blood glucose levels or a diagnosis of type 2 diabetes.

Doctors may not be able to diagnose metabolic syndrome in children younger than age 10. Children in this age group may still have traits of metabolic syndrome.

Experts do not know for sure why some children with NAFLD have NAFL while others have NASH. Research suggests that NASH is more common in children who have both NAFLD and type 2 diabetes.³

Genes

Certain genes may increase a child’s chance of developing NAFLD. These genes may explain why NAFLD is more common in Hispanic and Asian American children than in Black children. Genes may also explain why NAFLD sometimes runs in families.

Experts are still studying the genes that may play a role in NAFLD.

Other factors

Scientists are studying other factors that may play a role in causing or worsening NAFLD in children. These include

• birthweight. Research suggests that children who had a high or low birthweight are more likely to develop NAFLD.
• changes in the microbiome—the bacteria in the digestive tract that help with digestion. Studies have found differences between the microbiomes of children who have NAFLD and those who do not.
• diets high in fructose—a sugar that is part of table sugar and is also commonly added to sweeten drinks and foods. Studies suggest that diets high in fructose may increase the risk of NAFLD.

Is NAFLD the only cause of fatty liver in children?

Fatty liver may have causes other than NAFLD. If medical tests suggest that a child has a buildup of fat in the liver, the doctor may ask questions and order tests for other causes.

Other causes of fatty liver in children include

• disorders, called lipodystrophies, that cause a child’s body to use or store fat improperly
• celiac disease
• rapid weight loss or malnutrition
• some medicines, including those used to treat mental disorders, nervous system disorders, or skin conditions
• exposure to some toxins
• rare genetic diseases, such as Wilson disease and hypobetalipoproteinemia
• alcohol-associated liver disease—damage to the liver and its function due to excessive alcohol consumption

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