Non Alcoholic Steatohepatitis (NASH) is a type of fatty liver disease, characterized by inflammation of the liver with concurrent fat accumulation in liver. Mere deposition of fat in the liver is termed steatosis, and together these constitute fatty liver changes.
There are two main types of fatty liver disease: alcohol-related fatty liver disease and non-alcoholic fatty liver disease (NAFLD). Risk factors for NAFLD include diabetes, obesity and metabolic syndrome. When inflammation is present it is referred to as alcoholic steatohepatitis and nonalcoholic steatohepatitis (NASH). Steatohepatitis of either cause may progress to cirrhosis, and NASH is now believed to be a frequent cause of unexplained cirrhosis (at least in Western societies). NASH is also associated with lysosomal acid lipase deficiency.
This video is fairly technical, but well worth the time to watch. Dr. Stephen Harrison, Hepatologist and international opinion leader in fatty liver disease and NASH, discusses the evolving landscape of fatty liver disease in the United States as well as diagnostic approaches to identify patients at risk for this disease.
With NAFLD, there are usually no symptoms. Some people may develop signs such as tiredness but fatty liver disease is usually a silent killer.
If develop NASH or cirrhosis, you may have symptoms such as:
- Swollen belly
- Enlarged blood vessels underneath your skin’s surface
- Larger than normal breasts in men
- Red palms
- Skin and eyes that appear yellowish, due to a condition called jaundice
Fatty liver is a reversible condition wherein large vacuoles of triglyceride fat accumulate in liver cells via the process of steatosis (i.e., abnormal retention of lipids within a cell). Despite having multiple causes, fatty liver can be considered a single disease that occurs worldwide in those with excessive alcohol intake and the obese (with or without effects of insulin resistance). The condition is also associated with other diseases that influence fat metabolism. When this process of fat metabolism is disrupted, the fat can accumulate in the liver in excessive amounts, thus resulting in a fatty liver. It is difficult to distinguish alcoholic FLD, which is part of alcoholic liver disease, from nonalcoholic FLD (NAFLD), and both show microvesicular and macrovesicular fatty changes at different stages.
The accumulation of fat in alcoholic or non-alcoholic steatosis may also be accompanied by a progressive inflammation of the liver (hepatitis), called steatohepatitis. This more severe condition may be termed either alcoholic steatohepatitis or non-alcoholic steatohepatitis (NASH).
Severe fatty liver is sometimes accompanied by inflammation, a situation referred to as steatohepatitis. Progression to alcoholic steatohepatitis (ASH) or non-alcoholic steatohepatitis (NASH) depends on the persistence or severity of the inciting cause. Pathological lesions in both conditions are similar. However, the extent of inflammatory response varies widely and does not always correlate with degree of fat accumulation. Steatosis (retention of lipid) and onset of steatohepatitis may represent successive stages in FLD progression.
Liver disease with extensive inflammation and a high degree of steatosis often progresses to more severe forms of the disease. Hepatocyte ballooning and necrosis of varying degrees are often present at this stage. Liver cell death and inflammatory responses lead to the activation of hepatic stellate cells, which play a pivotal role in hepatic fibrosis. The extent of fibrosis varies widely. Perisinusoidal fibrosis is most common, especially in adults.
The progression to cirrhosis may be influenced by the amount of fat and degree of steatohepatitis and by a variety of other sensitizing factors. In alcoholic FLD, the transition to cirrhosis related to continued alcohol consumption is well-documented, but the process involved in non-alcoholic FLD is less clear.
Historically fatty liver was viewed as being mostly benign. The theory was that while liver fat might make the organ vulnerable to other problems it was, after all just normal fat. This view naturally led to medicine focusing on other problems where symptoms existed. I thought that view made little sense if only because fat people died younger but the science wasn't there so that remained the story.
Research is now coming out which shows that a fatty liver is an active cause of disease in other organs. Did you ever wonder why people frequently get fat then get type 2 diabetes? Consider all the effort devoted to diabetes in the management of the symptoms and the long term medical needs. German research has now shown that a fatty liver begins to produce different secretions, such as one called fetuin-A, into the blood stream. Those substances enter other organs and trigger reactions there.
This image from IDM shows pancreatic islet cells surrounded by fat cells. The study was reported in Science Daily at this link but I'll summarize it below.Read more
There are many ways to support the efforts of the Fatty Liver Foundation. General purpose donations are welcome from anyone concerned about public health in general or liver disease specifically. At the program level, we invite sponsorship in the following ways:
The Platinum level sponsor has provided a contribution to the Foundation of at least $200,000. Platinum sponsors may fund a mobile screening system or other project of interest and may be featured prominently with logos and other information in all of our media efforts promoting their support for public health.
The Gold level sponsor has provided a contribution to the Foundation of at least $100,000. Gold sponsors have the opportunity to direct their contributions to particular projects in partnership with the Foundation. While the screening project is our most visible patient outreach program but there are many needs within the obesity, fatty liver, and cirrhosis challenged patients that benefit from efforts surrounding the screening events.
The Silver level sponsor is anyone who has provided a contribution to the Foundation of at least $50,000. Silver level sponsors are honored on our sponsorship webpage with their logo and a link to their webpage for more information.
The Bronze level sponsor is anyone who has provided a contribution to the Foundation of at least $10,000. They are honored on our sponsorship webpage with their logo in recognition of their contributions.
Blue ribbon level contributions are all those less than $10,000. They are honored on our sponsorship webpage with their logo in recognition of their contributions.
Whatever level of support you can give is greatly appreciated and will be used to maximize benefit for current and future patients of liver disease and the complications of obesity which is at the heart of most fatty liver disease.