Fatty liver

The fatty liver ( steatosis ) is a common disease of the liver with usually reversible storage of fat (mainly triglycerides ) in the liver cell ( hepatocyte) in the form of fat vacuoles, eg by nutrition ( hyperalimentation ), alcohol abuse, drugs and toxins, diabetes mellitus, pregnancy, protein deficiency, liver congestion, liver partial removal or bypass operations, turn off the parts of the small intestine.

Let next to the fat deposition also demonstrate signs of inflammation, we speak of a fatty liver hepatitis ( steatohepatitis = ).

Pathophysiology

The fatty liver is due to a disturbance of fatty acid and Triglyceridstoffwechsels the liver cell and therefore can have different causes. The majority of fatty liver disease is due to an imbalance between caloric intake ( through food ) and calories burned ( physical activity) in which ( a calorie surplus ) leads to a positive energy balance.

Alcohol is a caloric value of 7.1 kcal / g very energetic and has a harmful effect on the liver cell. By metabolism by the enzyme alcohol dehydrogenase (ADH ) is formed acetaldehyde. This is metabolized by acetaldehyde dehydrogenase ( ALDH ) to acetic acid. In the degradation of alcohol by ADH NADH is produced in excess, so that the NADH / NAD ratio is increased. This means that acetyl-CoA formed can not be removed and is used for the formation of fatty acid mainly in the liver. Since too much fatty acid is present in the liver, it can not be removed sufficiently above the pre- β - lipoproteins in the adipocytes. The triglycerides remain in the liver, and there is a fatty liver.

Fatty liver can also occur as a result of chronic malnutrition (hunger and thirst), in that even with anorexia. From carbohydrates ( reducing units of carbohydrates → monosaccharides such as glucose ) glycogen is formed normally in the liver and stored. This provides energy through glycogenolysis ready quickly. Are the carbohydrate stores empty, uses the gluconeogenesis. While glucose is synthesized in the liver and kidneys from non- carbohydrate precursor such as glukoplastischen amino acids, which are obtained mainly in starvation of degraded muscle protein. If as a result of malnutrition or hunger is not fed (daily 0.8 g / kg body weight) enough protein, it comes to disruption of gluconeogenesis because the required energy to burn fat from muscle and connective tissue is not sufficiently available. It comes to the deposition of the non- metabolized fats at (triglycerides ) and in the vicinity of the liver.

By an increase of SHBG protein, there is a increase in the risk of age diabetes.

Classification

When inflammation of the liver ( steatohepatitis ) is demonstrated, the disease can progress to liver cirrhosis ( in about 10 % of cases).

Fatty liver is a common condition. Approx. 25 % of the adult western population have a fatty liver. The cause of fatty liver is probably due to unhealthy lifestyles. It is associated with obesity, diabetes and lack of physical activity. Probably the fatty liver is an early sign of the metabolic syndrome, the prediabetes.

Diagnostics

A fatty liver usually falls on a sonography enlargement and increased echogenicity compared with the kidney as well as a crude form or in a magnetic resonance imaging. If for other reasons, a biopsy of the liver is performed, time assuring histological fatty liver. Laboratory tests can result in no positive proof, but often fall to a slightly elevated transaminases and elevated γ - GT. The severity can be determined by special magnetic resonance imaging or elastography methods.

Therapy

A fatty liver (without signs of liver inflammation) has little clinical significance. However, since it can turn into a steatohepatitis and it can be an early sign of the metabolic syndrome, the following recommendations can be given:

• Reduction in caloric intake
• Increase the calorie consumption
• Alcohol abstinence

Tissue

Histologically, the distinction is großtropfige ( makrovesikuläre ) form with displacement of the nucleus to the edge and the kleintropfige ( microvesicular ) Leberzellverfettung and transitional forms. The großtropfige form is for example at the ASH before, the kleintropfige example in the fatty liver of pregnancy.