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What is NASH?
By Deborah Ng
Non-Alcoholic Fatty Liver Disease, or NAFLD, occurs when excess fat builds up in the liver, unrelated to alcohol consumption. When fat buildup causes inflammation or damage to cells, it’s called Non-Alcoholic Steatohepatitis, or NASH. NASH is a more serious form of NAFLD and if not treated, it can lead to liver damage.1
What is NASH?
When the body takes in or generates more fat than it should, the liver cells, called hepatocytes, cannot break fat down fast enough to eliminate it. As a result, some of the excess fat is stored in the liver, resulting in NAFLD.2 When NAFLD progresses to its most advanced stage, it becomes NASH.
With NASH, excess fat in the liver can act as a toxin, causing inflammation and cell injury. This can cause scarring, which leads to more serious liver conditions such as cirrhosis, liver cancer, or even liver failure.3 Though the liver can regenerate, long-term damage associated with NASH cannot be reversed.
Who gets NASH and how?
Researchers face many unknowns as to why NASH occurs in some people and not others with a similar medical history. There are, however, common risk factors among those who have this condition.1
NASH can occur at any age and in any gender. People who are obese or have insulin resistance are at a higher risk of having NASH. Due to the growing number of children with obesity, NASH is the most common liver ailment for children between the ages of 2 and 19.4
Other risk factors include high cholesterol, hypothyroidism, a poor diet and metabolic syndrome. Type 2 diabetes may also be related to NASH.5
NASH may be hereditary. If a person has family members who have or had NASH or NAFLD, they are at risk.1
What are the symptoms of NASH?
NASH is considered a “silent” disease, because many people experience few or no visible or obvious symptoms. The most common indicators associated with NASH are fatigue and pain on the upper right side of the abdomen. Other signs may include loss of appetite, weakness, nausea, swelling in the legs or abdomen, and jaundice.1
How is NASH diagnosed?
There is no simple way to determine if a patient has NASH. A physical examination can be used to determine a patient’s Body Mass Index (BMI) and physicians may look for symptoms associated with NASH, including jaundice, darkened skin patches that can indicate insulin resistance, and an enlarged liver.
A blood test can determine if there are increased levels of liver enzymes caused by fatty deposits. Additionally, ultrasounds can be used to determine the liver’s condition. The gold standard to effectively diagnose NASH is through a liver biopsy, an expensive and cumbersome procedure.1
How is NASH treated?
There are no U.S. Food and Drug Administration or European Medicines Agency approved medicines for NASH, but numerous therapies under clinical investigation.
Currently, those who have NASH are encouraged to commit to lifestyle changes, including altering their diet to remove fatty, cholesterol-laden foods and replace them with lean protein, healthy fruits, vegetables, and low-fat dairy products. In addition to a healthier diet, those with NASH are encouraged to exercise regularly to reduce fat and maintain a healthy weight.1
1 National Institute of Diabetes and Digestive and Kidney Diseases, Definition and Facts of NAFLD and NASH. Updated November 2016. Accessed November 3, 2017.
2 World J Gastroenterol. 2014 Sep 28; 20(36): 12956–12980.; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4177476/pdf/WJG-20-12956.pdf
3 Diehl, Anna and Day, Christopher M.D Cause, “Pathogenesis, and Treatment of Nonalcoholic Steatohepatitis.” N Engl J Med 2017; 377:2063-2072
4 Nierengarten, MA Mary Beth. “Pediatric Nonalcoholic Fatty Liver Disease.” Contemporary Pediatrics, 1 Sept. 2013, http://contemporarypediatrics.modernmedicine.com/contemporary-pediatrics/content/tags/biomarker/pediatric-nonalcoholic-fatty-liver-disease
5 Margariti E, Deutsch M, Manolakopoulos S, et al. Nonalcoholic fatty liver disease may develop in individuals with normal body mass index. Ann Gastroenterol. 2012