Introduction to Fatty liver

Steatosis, or fatty liver, is the accumulation of triglycerides and other fats in liver cells. In severe fatty liver, fat constitutes as much as 40% of the liver’s weight (as opposed to 5% in a normal liver); the liver’s weight may increase from 3.3 lb (1.5 kg) to as much as 11 lb (5 kg).
Minimal fatty changes are temporary and asymptomatic; severe or persistent changes may cause liver dysfunction. Fatty liver is usually reversible by simply eliminating the cause. This disorder may result in recurrent infection or sudden death from fat emboli in the lungs.

Causes
The most common cause of fatty liver in the United States and Europe is chronic alcoholism, with the severity of liver disease directly related to the amount of alcohol consumed. Other common, non-alcohol-related causes include acquired immunodeficiency syndrome, drug toxicity, and pregnancy.
Other causes include malnutrition (especially protein deficiency), obesity, diabetes mellitus, jejunoileal bypass surgery, Cushing’s syndrome, Reye’s syndrome, carbon tetrachloride intoxication, prolonged total parenteral nutrition (TPN), and DDT poisoning.
Whatever the cause, fatty infiltration of the liver probably results from mobilization of fatty acids from adipose tissues or from altered fat metabolism.

Signs and symptoms
Clinical features of fatty liver vary with the degree of lipid infiltration, and many patients are asymptomatic. The most typical sign is a large, tender liver (hepatomegaly). Common symptoms include right upper quadrant pain (with massive or rapid infiltration), ascites, edema, jaundice, and fever (all with hepatic necrosis or biliary stasis).
Nausea, vomiting, and anorexia are less common. Splenomegaly usually accompanies cirrhosis. Rarer changes are spider angiomas, varices, transient gynecomastia, and menstrual disorders.

Diagnosis
Typical clinical features—especially in patients with chronic alcoholism, malnutrition, poorly controlled diabetes mellitus, or obesity—suggest fatty liver. A liver biopsy confirms excessive fat in the liver. The following findings on liver function tests support this diagnosis:

• albumin—somewhat low
• globulin—usually elevated
• cholesterol—usually elevated
• bilirubin—elevated
• alkaline phosphatase—elevated
• transaminase—usually low (less than 300 units)
• prothrombin time—possibly prolonged.

Other findings may include anemia, leukocytosis, albuminuria, hyperglycemia or hypoglycemia, and deficiencies of iron, folic acid, and vitamin B12.

Treatment
The treatment for fatty liver is essentially supportive and consists of correcting the underlying condition or eliminating its cause. Fatty liver that results from TPN may be ameliorated or prevented by giving choline.
In alcoholic fatty liver, abstinence from alcohol and a proper diet can begin to correct liver changes within 4 to 8 weeks. This requires comprehensive patient teaching.
Depending on the degree of severity, the patient may need to undergo liver transplantation.

Special considerations

• Assess for malnutrition, especially protein deficiency, in those with chronic illness. Instruct the patient about what constitutes an adequate diet.
• Monitor an obese patient’s progress in losing weight. Provide positive reinforcement for any weight loss.
• Perform comprehensive patient teaching, especially for obese, alcoholic, and diabetic patients.