An excess storage of fats and sugars in the cells of the liver as triglycerides.
What is Nonalcoholic Fatty Liver Disease (NAFLD)?
This is a condition characterized by an excess storage of fats and sugars in the cells of the liver as triglycerides. The liver is the largest organ in the body and plays a role in processing everything that you eat, drink, breathe, and absorb through your skin. If triglyceride stores are increased in more than 5% of the liver it is called "fatty liver." NAFLD can become more serious if associated with inflammation known as nonalcoholic steatohepatitis (NASH), which can lead to progressive scarring (fibrosis), liver failure, or liver cancer. Changes seen in liver cells from nonalcoholic fatty liver are similar to those that result from drinking too much alcohol. Both require attention to avoid progression of liver disease.
Those who are considered to be overweight or obese with a BMI of 25 or higher may be at risk for NAFLD. A person’s race or ethnicity may determine when his/her weight becomes a factor in the accumulation of fat in the liver. Some ethnic groups tend to develop fatty liver at a lower BMI. Those who tend to gain weight in their abdomen (belly) instead of their hips are more likely to develop fatty liver. Fatty liver is commonly associated with adult onset diabetes.
What Causes Nonalcoholic Fatty Liver Disease?
There are predisposing factors to NAFLD & NASH that often occur in order:
- A person is overweight or obese
- Extra weight leads to insulin resistance--cells of the body do not allow insulin to transport sugar inside the cell.
- Fats and sugars are deposited in the liver as triglycerides.
- The increased levels of triglycerides trigger inflammation in about 20-25% of people with NAFLD. This is called nonalcoholic steatohepatitis or NASH.
- NASH can lead to fibrosis (scarring) of the liver.
Fatty liver does NOT always cause inflammation in the liver. However, those with fatty liver who abuse alcohol or have other conditions that affect the liver are at increased risk.
Nonalcoholic steatohepatitis (NASH) is inflammation in the liver triggered by the Fatty Liver. Inflammation in the cells can lead to scarring (fibrosis). The most certain way to tell the difference between NASH and fatty liver is by biopsy.
Liver cirrhosis is extensive scarring in the liver. Risk factors for the development of cirrhosis are diabetes, obesity, and alcohol abuse.
Liver failure: liver related symptoms that result from progressive fibrosis and damage of the liver. Both cirrhosis and liver failure are life-threatening conditions. People with cirrhosis are also at an increased risk for liver cancer.
What Are the Symptoms of Nonalcoholic Fatty Liver Disease?
Most people with fatty liver disease do not have symptoms. Some people may describe being tired or having right sided abdominal pressure or discomfort. Those who develop cirrhosis often do not have symptoms in the early stages. As liver failure progresses, symptoms may develop such as:
- Yellowing of the skin or eyes (jaundice)
- Fluid collection in the abdomen (ascites)
- Bleeding in the esophagus, stomach, or intestines
- Mental confusion (encephalopathy)
How is Nonalcoholic Fatty Liver Disease Diagnosed?
There is not one specific test for diagnosis. It is often found during routine testing as most people do not have symptoms of fatty liver disease. The following tests may be obtained to make the diagnosis:
- Liver enzyme blood tests: ALT and AST may be elevated in people with fatty liver
- Ultrasound: imaging used to look at the size, shape, texture, and blood supply to the liver
- CT (computed tomography) and MRI (magnetic resonance imaging) scan
- Liver biopsy: Liver biopsy is performed with ultrasound and a needle to sample a small piece of the liver tissue. The results may show fat in the liver, inflammation caused by the fat, or scarring. Liver biopsy is the most definitive way to tell the difference between nonalcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH).
- Other causes of liver disease must also be evaluated
How is Nonalcoholic Fatty Liver Disease Treated?
Your healthcare provider will work to treat the underlying conditions that are contributing to your liver disease. Your healthcare provider may recommend weight loss and physical activity and could also prescribe medications to control cholesterol and blood sugar. These interventions may reduce the amount of fat and inflammation in the liver preventing progression to more serious liver disease.
Dietary recommendations include: avoiding high sugar foods and drinks such as pop, limiting carbohydrates in generally placing more emphasis on some protein in each meal, do not skip meals, generally restrict calories with intention of slowly losing weight over time.
- Fresh fruits and vegetables
- Whole grains
- Lean meats such as chicken, turkey, lean pork, and fish
- Low fat dairy options
- May help to reduce abdominal fat
- May help control type 2 diabetes and high cholesterol
When to seek immediate medical advice:
If symptoms of liver failure including yellowing of skin/eyes/urine, black stool or bloody stool, fluid collection in the abdomen, or confusion develop, contact your healthcare provider.