Fatty Liver Disease
General information:
• If the amount of triglycerides in hepatocytes is more than 5% of the liver weight, liver fat is mentioned.
• Microscopically, only hepatocytes have lubrication, but if there is no inflammation or necrosis in the parenchyma, it is defined as simple lubrication or hepatosteatosis.
• If there is parenchymal inflammation and/or necrosis with microscopic lubrication, this is called fatty hepatitis or steatohepatitis, and fibrosis may occur in the liver as a result.
• The most important causes of fatty liver are insulin resistance and alcohol.
Etiology:
• Fatty liver disease is examined histologically in two groups according to the size of the fat vesicles (micro or macro) in hepatocytes.
• Macrovesicular adiposity is frequently seen and is mostly associated with insulin resistance or alcohol.
• Acute liver failure may develop in microvesicular steatosis.
Macrovesicular lubrication:
Insulin resistance (obesity, metabolic syndrome, diabetes)
Alcohol
Other pathologies: Protein-calorie malnutrition, total parenteral nutrition, jejunoileal bypass, Hepatitis C, Wilson's disease
Medications: Methotrexate, glucocorticoid, amiodarone, and estrogen
Microvesicular lubrication:
Reye's syndrome
acute fatty liver of pregnancy
Medications: Tetracycline, valproic acid, aspirin, antiretrovirals.
Non-Alcoholic Fatty Liver Diseases
General information:
• Obesity and insulin resistance play a role in its pathogenesis.
• It is a spectrum extending from simple lubrication to cirrhosis and HCC.
Non-alcoholic fatty liver (Non-Alcoholic Fatty-Liver / NAFL): There is only simple adiposity.
Non-alcoholic fatty hepatitis (Non-Alcoholic Steatohepatitis / NASH): In addition to lubrication, there is inflammation and/or necrosis in the parenchyma.
NASH progresses to chronic liver disease (fibrosis), cirrhosis, and HCC.
• Non-alcoholic fatty liver diseases are accepted as liver findings of metabolic syndrome and are often associated with metabolic syndrome (obesity, DM, hyperlipidemia, HT).
• Non-alcoholic fatty liver diseases are the most common chronic liver disease.
Clinic:
• It is usually asymptomatic.
• There may be right upper quadrant pain and fullness due to hepatomegaly.
• Macrovesicular steatosis can progress to chronic hepatitis, cirrhosis and cancer (HCC}, especially if it is due to NASH.
• In NASH, male gender, obesity, diabetes mellitus, age > 50 and high AST increase the possibility of advanced fibrosis and cirrhosis.
Diagnosis:
• The most common laboratory finding is mild to moderate elevation of liver enzymes.
• The most common cause of ALT/AST elevation in the community is non-alcoholic fatty liver disease.
• The first radiological method to be requested in liver imaging is USG.
There is an increase in liver echogenicity on USG.
• The definitive diagnosis of NASH is made by liver biopsy.
Treatment:
• Lifestyle change, diet and exercise are recommended.
• Oral antidiabetics metformin and pioglitazone can be given in the treatment of NASH.
Vitamin E can also be used as an alternative:
• Obesity surgery can regress NASH.