Pediatric Non-alcoholic Fatty Liver Disease (NAFLD)

What Is Non-Alcoholic Fatty Liver Disease?

Non-alcoholic fatty liver disease (NAFLD) is when excess fat accumulates in the liver. It is the most common cause of liver disease in children in the United States. Though a mild condition with less visible symptoms, it can progress to a more severe form of liver disease that causes scarring of the liver tissue (cirrhosis) or liver cancer in adulthood if left untreated. The more severe form of the disease is called non-alcoholic steatohepatitis (NASH).

How Common Is NAFLD in Children?

NAFLD is the most common form of liver disease affecting about ten percent of children in the United States.It is the second most common cause of liver transplantation in the pediatric population. It has affected about 30 million children, of whom around 8.6 million have a more severe form of the disease, NASH.

Who Is at an Increased Risk of Developing NAFLD?

Risk factors for developing NAFLD include the following:

• Boys have twice the risk of developing NAFLD when compared to girls.

• Children of Hispanic origin followed by Caucasian descent.

• Children who are obese.

What Are the Causes of Non-Alcoholic Fatty Liver Disease (NAFLD)?

The exact cause of NAFLD is not known. Genetic factors also influence NAFLD, one gene, in particular, is the PNPLA3. However, researchers have reported that the following conditions can be the probable cause of NAFLD:

• Obesity.

• Prediabetes (a condition that develops before type 2 diabetes when the blood sugars are high without any other noticeable symptoms).

• Type 2 diabetes.

• Insulin resistance.

• Hyperlipidemia (a condition in which all types of fats are high in the body).

• Rapid weight loss.

• Hepatitis C (a viral infection that causes inflammation of the liver).

Initially, steatosis progresses to steatohepatitis to fibrosis and finally to cirrhosis.

What Are the Risk Factors for Non-Alcoholic Fatty Liver Disease (NAFLD)?

The following are the risk factors for developing NAFLD:

1. High cholesterol.

2. High triglyceride levels.

3. Sleep apnea (a condition in which there is an interruption to breathing during sleep).

4. Metabolic disorders are a group of disorders that lead to increased heart problems and related issues.

What Are the Symptoms of Pediatric Non-Alcoholic Fatty Liver Disease (NAFLD)?

In most cases, NAFLD does not present any visible symptoms. On examination, the doctors may notice an enlargement of the liver or obesity, more predominantly in the waist area. Acanthosis nigricans, a condition in which there is discoloration of the neck and armpits, indicating insulin resistance, is also a symptom of NAFLD.

Routine check-ups of the child may show abnormal blood test readings. In some cases, the child may show symptoms like pain in the abdomen, tiredness, constipation, weakness, and weight loss.

What Are the Complications of Pediatric Non-Alcoholic Fatty Liver Disease (NAFLD)?

NAFLD being a chronic condition, requires regular medical care for the child’s entire life. The liver tissue begins to scar when NAFLD progresses to NASH (non-alcoholic steatohepatitis). The soft and healthy liver tissue gets scarred, causing cirrhosis which prevents the liver from functioning properly. If left untreated, cirrhosis can lead to complications like portal hypertension (a serious complication in which there is pressure build-up in the blood vessels supplying the liver), liver failure, or cancer of the liver. These complications may require liver transplantation. Though serious, the complications can be prevented if the fat build-up in the liver cells can be slowed down or stopped. Extrahepatic manifestationslike cardiovascular disease, low bone mineral density, and type II diabetes can also be presented.

How Is Pediatric Non-Alcoholic Fatty Liver Disease (NAFLD) Diagnosed?

The doctor diagnoses NAFLD based on a combination of medical history, physical examination, signs and symptoms, and blood tests. The following tests may be ordered by the health care worker to confirm the diagnosis:

• Blood Tests: Kids with obesity and whose blood tests show higher than normal values of certain liver enzymes like aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT) have more chances of having NAFLD.

• Ultrasound Scan: An ultrasound scan of the liver helps assess the structure of the liver. An ultrasound scan is a painless, non-invasive technique that uses high-frequency sound waves to create images of body parts.

• Transient Elastography (Fibro Scan): Transient elastography is a non-invasive technique used to assess liver fibrosis by measuring liver stiffness. This technique also determines the amount of liver fat. It is done in patients with long-standing (chronic) liver disease.

• Liver Biopsy: Liver biopsy, in which a needle is inserted through the skin to collect a small amount of liver tissue that is sent to the laboratory to be examined under a microscope. A biopsy helps detect the build-up of fat in the liver cells and scarring of the liver tissue. Liver biopsy is used to differentiate between non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) in children.

Children diagnosed with NAFLD require periodic monitoring to check the levels of the following:

• Blood tests to check for the levels of liver enzymes.

• Ultrasound scan of the abdomen.

• Transient elastography.

• Regular physical examination.

A check for prediabetes and high cholesterol levels is done. The doctors may also order tests to rule out other liver disorders like:

• Autoimmune hepatitis (the body's immune system destroys liver cells, causing liver inflammation).

• Viral hepatitis (inflammation of the liver caused due to viral infections).

• Wilson’s disease (a genetic condition that causes copper accumulation in cells of the liver, brain, and other organs).

How Is Pediatric Non-Alcoholic Fatty Liver Disease (NAFLD) Treated?

• There is no medicine or cure for NAFLD in particular. However, eating healthy, getting regular exercise, and managing weight are the key points that help prevent the progression of NAFLD into a more severe condition.

• A team of doctors that includes GI (gastrointestinal) specialists for children, a dietician, and psychologists together can help in the better management of the condition.

• Healthy eating is encouraged in children to help them lose weight. Foods rich in fiber and whole grains are emphasized, along with teaching the child to resist cravings for sugar-loaded foods. A weight loss of ten percent has been shown to improve the liver condition. Regular physical activity at least three to five times a week for 30 minutes each time is necessary.

• Studies suggest the benefits of taking vitamin E and antioxidants. However, they are not a replacement for healthy eating, physical activity, and weight loss.

Conclusion:

Pediatric non-alcoholic fatty liver disease is the most common form of liver disease in children in the United States. The most common reason is obesity. Early identification and necessary lifestyle changes, as suggested by the doctor, help prevent the condition from proceeding into a more severe form that may cause complications or a need for a liver transplant. Mindful eating, regular exercise, and an active lifestyle, along with keeping a check on weight gain, can give a positive outlook on the condition.