Non-alcoholic Fatty Liver Disease (NAFLD): Causes, Symptoms, Treatment and Prevention
Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder that occurs due to the excess fat buildup in the liver cells. People who consume alcohol mostly are affected with liver diseases, but NAFLD is due to other reasons, such as obesity and insulin resistance. NAFLD leads to enlargement of the liver and upper abdominal pain, and the most common complication is cirrhosis (scarring).
It occurs in every age, but most commonly affects people above 40 or 50 years of age. Approximately 9 to 36.9% of the population is affected with NAFLD in different parts of the world.
- What is Non-alcoholic Fatty Liver Disease (NAFLD)?
- What are the Causes of Non-alcoholic Fatty Liver Disease (NAFLD)?
- What are the Signs and Symptoms of Non-alcoholic Fatty Liver Disease (NAFLD)?
- What are the Risk Factors for Non-alcoholic Fatty Liver Disease (NAFLD)?
- What are the Complications of Non-alcoholic Fatty Liver Disease (NAFLD)?
- How to Diagnose Non-alcoholic Fatty Liver Disease (NAFLD)?
- What is the Treatment for Non-alcoholic Fatty Liver Disease (NAFLD)?
- What are the Preventive methods that Reduce the Risk of Non-alcoholic Fatty Liver Disease (NAFLD)?
What is Non-alcoholic Fatty Liver Disease (NAFLD)?
Non-alcoholic fatty liver disease is a single term used for various liver conditions that is caused by fat accumulation in the liver. NAFLD affects people who are not addicted to alcohol or rarely drinks alcohol. It occurs due to an abnormality of the fat metabolism in the liver.
The liver helps in the metabolism of fat and exports it to other body parts. In NAFLD the function of liver gets disturbed that leads to the accumulation of fat in the hepatocytes (liver cells).
What are the Causes of Non-alcoholic Fatty Liver Disease (NAFLD)?
The exact cause of NAFLD is not completely understood. However, this might occur due to the following factors:
Obesity and overweight people can accumulate fat in the body. This stored fat in the liver becomes metabolically active and affects the liver cells causing inflammation.
Insulin resistance is another factor in which the body fails to respond to insulin appropriately. Insulin is the hormone produced by the pancreas that helps in the uptake of glucose from the blood by the cells. In case of insulin resistance, the antilypolytic effect of insulin is compromised leading to increased number of free fatty acids. This in turn leads to dysfunction of the mitochondria causing lipotoxicity (liver toxicity).
It results in NAFLD and other severe forms, such as non-alcoholic steatohepatitis (NASH).
What are the Signs and Symptoms of Non-alcoholic Fatty Liver Disease (NAFLD)?
NAFLD usually has no signs and symptoms. In chronic cases, the signs and symptoms may include:
- Enlarged liver (hepatomegaly)
- Fatigue (lethargy)
- Pain in the upper abdomen on the right side
Some signs and symptoms, when NAFLD progresses to NASH and cirrhosis are:
- Belly swelling (ascites)
- Enlarged blood vessels under the skin surface
- Enlarged breast in men
- Red palms
What are the Risk Factors for Non-alcoholic Fatty Liver Disease (NAFLD)?
Many factors can increase the risk of NAFLD, which include:
- High cholesterol
- High levels of triglycerides in the blood
- High blood pressure
- People aged above 50 years
- Metabolic syndrome
- Sleep apnea
- Type 2 diabetes
- Use of corticosteroids
- Certain medications for cancer, such as Tamoxifen for breast cancer
What are the Complications of Non-alcoholic Fatty Liver Disease (NAFLD)?
Cirrhosis: It is the main complication of NAFLD that causes scarring (fibrosis) of the liver. Cirrhosis may develop due to liver injury and inflammation during NASH. As inflammation continues to occur, fibrosis also spreads to the liver rapidly. It can further lead to the following complications, such as:
- Ascites (fluid buildup within the abdomen)
- Esophageal varices (the veins in the esophagus swell that can rupture and bleed)
- Hepatic encephalopathy (decline in brain function due to liver failure)
- Liver cancer
- Liver failure
How to Diagnose Non-alcoholic Fatty Liver Disease (NAFLD)?
NAFLD usually causes no symptoms. The diagnosis can be done by doing blood tests and imaging tests.
Blood tests for NAFLD called as liver function tests, which measures the level of liver enzymes in the blood that indicates the underlying liver diseases and to rule out other conditions.
Different Blood Tests that are Performed for the Diagnosis of NAFLD Include:
- Complete blood count (CBC)
- Liver function test (liver enzyme test)
- Tests for chronic hepatitis (hepatitis A, C and others)
- Screening test for celiac disease
- Fasting blood sugar test
- Hemoglobin A1C test (to know the stability of blood sugar)
- Lipid profile test (for measuring cholesterol and triglycerides in the blood)
Imaging tests are performed to locate the disease and to know the internal damage. It includes different tests:
Ultrasound: It is done to know the excessive amount of fat present in the liver. In this procedure, sound waves are used to take the images of the inner side of the liver.
CT scan or MRI: These are the other imaging methods that use radiations like X-rays to locate the problem and the extent of damage caused inside the particular organ.
Transient elastography: An advanced form of ultrasound that helps in measuring the stiffness of the liver. The stiffness in the liver indicates the presence of conditions like scarring or fibrosis.
Magnetic resonance elastography: This technique in combination with MRI gives information of the liver stiffness and the diseases associated with the liver (scarring or fibrosis).
Liver biopsy: A small tissue sample of the liver is extracted using a needle, which is examined in the lab for any traces of inflammation and scarring.
What is the Treatment for Non-alcoholic Fatty Liver Disease (NAFLD)?
There are no specific medications currently available for NAFLD, but by maintaining a healthy lifestyle the other associated conditions (high blood pressure, diabetes and cholesterol) can be treated.
Healthy Lifestyle Changes Include:
- Losing weight in case of obesity or overweight (first line of treatment for NAFLD)
- Eating a healthy and a nutritious diet that includes fruits, green leafy vegetables and whole grains
- Exercising regularly for 30 minutes daily
- Controlling the blood glucose and cholesterol levels
- Avoiding alcohol consumption
- Avoiding smoking
The doctor may suggest weight-loss surgery for those who are overweight and tend to lose more weight without following regular exercise and diet. Vaccinations are given in case of hepatitis A and B to protect the liver from further damage due to hepatitis virus. Liver transplantation is done in severe cases, such as cirrhosis and liver failure that occurs due to non-alcoholic steatohepatitis.
What are the Preventive methods that Reduce the Risk of Non-alcoholic Fatty Liver Disease (NAFLD)?
The risk of Non-alcoholic fatty liver disease can be reduced by the following methods, which include:
- Maintaining a healthy diet is the key to prevent NAFLD, as obese and overweight people accumulate more amount of fat in the body that alters the liver function and it is the primary cause of NAFLD.
- A well-balanced diet containing all the vital nutrients will keep a person healthy, and keeps blood pressure, cholesterol, sugar, triglycerides levels normal in the body.
- Regular exercise can maintain a healthy weight, which reduces the risk of NAFLD.