What are Metabolic dysfunction-Associated Steatotic Liver diseases?

Fatty Liver Disease

Fatty liver is a condition where fat accumulates in the liver. Under normal circumstances, a healthy liver contains little or no fat. Fatty liver disease is a broad condition that covers a wide range of liver diseases.

TYPES OF FATTY LIVER DISEASE

Alcoholic fatty liver
Metabolic dysfunction-Associated Steatotic Liver Disease

ALCOHOLIC FATTY LIVER DISEASE

Alcoholic Fatty Liver Disease is seen in people who consume alcohol heavily. The condition is reversible if the person stops drinking alcohol. However, if they continue to drink, it can progress to serious conditions like liver cirrhosis and liver failure.

METABOLIC DYSFUNCTION-ASSOCIATED STEATOTIC LIVER DISEASE

Metabolic dysfunction-Associated Steatotic Liver Disease as the name suggests is type of fatty liver disease with fat accumulation in liver that is not associated with significant consumption of alcohol, or other competing reasons for fatty liver and other co –existing liver diseases.

Spectrum of MASLD

Simple Fatty Liver

Simple fatty liver or MASLD is a condition where only fat is accumulated in the liver cells

Metabolic dysfunction-Associated Steatohepatitis

MASH is more severe form of MASLD, where along with fat accumulation there is inflammation and cell death in the liver with considerable scar (fibrous/hard) tissue formation

Why does fat gets accumulated in the liver?

Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) is an indicator of an abnormality in the metabolism (chemical processes) within the liver.

The liver is involved in the metabolism of fat, such as absorbing fat from the food we eat or from the blood and transporting fat to other parts of the body. Overall, the fat in the body is managed or handled by liver cells. In MASLD, the liver’s effective handling of fat is disturbed.

Where does the excess fat accumulated in liver come from?

The fat that is deposited in the liver comes from:

Fat from food
Free fatty acids from blood convert into fat in liver
Fat produced by the liver itself
Reduced transportation of fat from liver
Reduced disposal of fat from liver

What causes the metabolic disturbances in liver?

It is not yet fully established what exactly causes MASLD/MASH but studies have found that both MASLD and MASH are linked to underlying conditions like obesity, insulin resistance, metabolic syndrome, high levels of cholesterol, type 2 diabetes and certain medications.

What are signs and symptoms of MASLD?

There are no symptoms for MASLD and so it is called a silent disease. In majority of the cases it is accidentally identified during blood tests or imaging tests like ultrasonography and fibroscan.

Why is it important to consider MASLD?

It is very important to take MASLD seriously because :

MASLD is a sign of underlying conditions like type 2 diabetes.
MASLD has proven outcomes similar to those of type 2 diabetes, including liver fibrosis, liver cancer, heart diseases, and early death due to liver and heart complications.

MASH – METABOLIC DYSFUNCTION-ASSOCIATED STEATOHEPATITIS

MASH is the most severe form of MASLD characterized by abnormal accumulation of fat in the liver along with inflammation (hepatitis) and liver cell damage or cell death (ballooning). MASH can progress rapidly in many cases to fibrosis, cirrhosis and finally to liver failure or liver cancer.

MASH A SILENT KILLER

MASH generally doesn’t show any symptoms and is considered to be silent killer due to the very reason, but on few occasions some people with more severe fibrosis or cirrhosis may experience

A dull or aching pain over the upper right side of the stomach (lower right side of the ribs)
Extreme tiredness, weakness
Loss of weight and loss of appetite

Outcomes of MASH

The progressive nature of MASH has shown to contribute to the following complications

Metabolic dysfunction-Associated Steatotic Liver Diseases

Liver Fibrosis – accumulation of fat over a long period damages the liver cells, as a result the body reacts to injury by natural healing process with formation of fibrous (scar/hard) tissue replacing the damaged tissue. The scar tissue causes insufficient blood supply to the liver. Studies have shown that 37 – 41% of people with MASH have developed fibrosis of their liver over time

Liver Cirrhosis – Excessive fibrous tissue (scar tissue) over time progresses to cirrhosis of the liver. In cirrhosis a much stronger scar tissue (stage- 4 fibrosis) is formed which puts the patient in a greater danger of loss of liver function (end-stage-liver disease). Studies have also shown that 5% of people with MASH went on to develop cirrhosis of the liver.

Liver Failure – In patients with MASH related cirrhosis the liver may eventually fail to function due to extensive damage of the liver by cirrhosis, thus requiring a liver transplant to survive.

Heart diseases – Both MASLD and MASH can cause heart related diseases and it is shown in a study that 13% of people with MASH had higher chances of death from heart diseases.

Liver Cancer – Both MASLD and MASH are known to cause hepatocellular carcinoma, a type of liver cancer.

Other complications – It is a known fact that type 2 diabetes and metabolic syndrome go hand in hand, so people with MASH may develop type 2 diabetes or metabolic syndrome.

Increased chances of death – People with MASH have higher chances of death from liver and heart complications compared to general population without any liver diseases.

Reference:

Chalasani, N. , Younossi, Z. , Lavine, J. E., Charlton, M. , Cusi, K. , Rinella, M. , Harrison, S. A., Brunt, E. M. and Sanyal, A. J. (2018), The diagnosis and management of nonalcoholic fatty liver disease: Practice guidance from the American Association for the Study of Liver Diseases. Hepatology, 67: 328-357. doi:10.1002/hep.29367
Duseja A et al. (2015). Non-alcoholic Fatty Liver Disease and Metabolic Syndrome, J Clin Exp Hepatol. 2015 Mar;5(1):51-68. doi: 10.1016/j.jceh.2015.02.006. Epub 2015 Mar 6