Non-alcoholic fatty liver disease (NAFLD) is a condition of the liver that is characterized by fat accumulation (also known as steatosis) in the liver, occurring in individuals who consume little or no alcohol (equal to or less than two drinks per day in men and one drink per day in women). NAFLD is currently thought to be the most common type of liver disease in both adults and adolescents in the U.S. with rates of up to 25-30% of the U.S. population.
Categories of Non-Alcoholic Fatty Liver Disease
NAFLD can be separated into two categories:
- NAFLD or Simple steatosis: The presence of fat in the liver with no or little inflammation or scarring (fibrosis).
- Non-alcoholic steatohepatitis (NASH): Fat along with inflammation and varying amounts of scarring (fibrosis).
NASH is a progressive form of NAFLD where inflammation causes liver damage and scarring (fibrosis). Fibrosis can get worse over time and lead to extensive scarring of the liver (cirrhosis). Patients who develop cirrhosis are at risk for complications including liver failure and liver cancer (hepatocellular carcinoma). In addition to liver-related complications, patients with NAFLD and NASH are also at higher-than-usual risk for cardiovascular disease. In fact, heart disease is the number one cause of death for patients with NAFLD.
What are Risk Factors for NAFLD/NASH?
Patients with NAFLD/NASH tend to also have one or more features of the metabolic syndrome. Because of similar lifestyles and genetics, those with a family history of NAFLD may be at higher risk for developing the disease.
Metabolic Syndrome: Defined as having 3 or more of the following features
- Low HDL cholesterol (low levels of good cholesterol)
- High lipids called triglycerides
- High blood pressure
What are Symptoms of NAFLD/NASH?
Patients with NAFLD/NASH typically have no symptoms or specific findings on physical exam. Occasionally, patients will report vague discomfort in their right upper abdomen or fatigue.
How is NAFLD/NASH Diagnosed?
Diagnosis is not always simple because patients usually have no symptoms and liver tests can be completely normal. Diagnosis is typically made if testing for other causes of liver disease is negative and there are findings of fat deposition on imaging tests (like ultrasound, CAT scan or MRI).
Liver biopsy is the only way to accurately differentiate between NAFLD and NASH. Biopsy can also determine the extent of the damage and measure the degree of fibrosis (scar tissue). Noninvasive tests, like Fibroscan (transient elastography) and newer MRI imaging can also estimate the amount of fat and scar tissue in the liver
How is NAFLD/NASH Treated?
Active research is ongoing, but for now there are no FDA approved medications specifically for the treatment of NAFLD/NASH. However, studies have shown that both fat, inflammation and scar tissue can leave your liver. This means that NAFLD and NASH can be reversible.
Improving liver fat and inflammation is possible when people lose weight and/or modify their lifestyle. This is the first line treatment for NAFLD/NASH.
- Lifestyle modification includes adopting a healthy diet as well as increasing physical activity.
- Losing 10% of your total current body weight increases the likelihood that the amount of liver fat and inflammation will improve. Weight loss should be gradual (a goal of 1-3 pounds per week), as rapid weight loss can actually worsen liver disease.
Medications: Vitamin E
Patients with NASH diagnosed with a liver biopsy and who do not have diabetes, significant heart disease or cirrhosis will sometimes be asked to start Vitamin E as this is thought to help reduce liver inflammation.
Managing other Diseases
- Improving other metabolic diseases such as diabetes, high blood pressure and high cholesterol/lipids can also help NAFLD.
Moderate or heavy alcohol use can cause additional damage and fat accumulation in the liver in people with NAFLD. Therefore, patients with NAFLD should avoid alcohol entirely if possible. If you do not think you can completely stop drinking alcohol, it is important to minimize alcohol intake (less than 2 drinks per day for men and 1 drink per day for women).
Other Information About Digestive and Liver Health
To see related medical services we offer, visit our Digestive and Liver Health overview page.
Make an Appointment
At the University of Michigan Fatty Liver Disease Clinic, we provide the latest diagnostic and treatment options to patients with NAFLD/NASH, as well as access to cutting edge research trials that include new therapies under study. For more information about our NAFLD clinic, visit our NAFLD Clinic website or call to schedule an appointment toll-free at 844-233-0433.