Metabolic associated fatty liver disease
Metabolic associated fatty liver disease (MAFLD), previously known as non-alcoholic fatty liver disease (NAFLD), refers to liver disease which develops due to obesity and type 2 diabetes mellitus. The pathology and progression is similar as with alcoholic liver disease, but there is no alcohol abuse involved. It progresses similarly as ALD, from steatosis to non-alcoholic steatohepatitis (NASH) to cirrhosis.
In 2020, it was proprosed that NAFLD needs a new name to better describe its pathogenesis, namely metabolic associated fatty liver disease (MAFLD).
It’s a very common condition in the Western world.
Pathomechanism
Insulin resistance results in accumulation of triglycerides in hepatocytes due to these mechanisms:
- Impaired oxidation of fatty acids
- Increased synthesis and uptake of fatty acids
- Decreased hepatic secretion of VLDL cholesterol
The fat-loaded hepatocytes are very sensitive to lipid peroxidation products generated by oxidative stress, which can damage mitochondria and plasma membranes. This leads eventually to apoptosis of the hepatocytes. A consequence of oxidative stress or release from visceral adipose tissue is that the levels of TNF and IL-6 increase, contributing to liver damage and inflammation.