What is a fatty liver?
Fatty liver (steatosis hepatis) is a common disease of the liver usually reversible storage of fat (predominantly triglycerides) in the liver cell (hepatocyte) in the form of fat vacuoles, eg., By overeating (hyperalimentation), alcohol abuse, drugs, , off toxins and other poisons, diabetes mellitus, pregnancy, protein deficiency, liver congestion, liver partial resection or bypass surgery, the parts of the small intestine. Get next to the fat deposition also demonstrate signs of inflammation, we speak of a fatty liver hepatitis.
Fatty liver Pathophysiology
The fatty liver is due to a disorder of fatty acid and Triglyceridstoffwechsels the liver cell and therefore can have different causes. Most of the fatty liver disease based on an imbalance between caloric intake (through food) and calories burned, which (a calorie surplus) leads to a positive energy balance.
Alcohol is a calorific value of 7.1 kcal / g very energetic and has a harmful effect on liver cells. By metabolism by the enzyme alcohol dehydrogenase (ADH) is formed acetaldehyde. This is metabolized by acetaldehyde dehydrogenase (ALDH) to acetic acid. In the breakdown of alcohol by ADH NADH is produced in excess, so that the NADH / NAD ratio is increased. This means that formed acetyl-CoA can not be broken down and used for fatty acid formation 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 adipose tissue cells. The fatty acids are esterified to triglycerides (fat). These remain in the liver, and it creates a fatty liver. The triglyceride concentration in healthy humans in the liver is about 5% in the fatty liver can be up to 50%. This fatty liver is initially completely reversible and leads only to the time irreparable damage.
Fatty liver can also be as a result of chronic malnutrition (for example, malnutrition) may occur, so far even with anorexia. From carbohydrates (decomposition 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. In this case, glucose is synthesized in the liver and kidneys from non-carbohydrate precursors, such as amino acids glukoplastischen obtained especially in starvation of degraded muscle protein. If as a result of malnutrition or hunger not fed (daily 0.8 g / kg body weight) enough protein, it is the 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 the protein leads to an increase of SHBG in the risk of age diabetes.
Diagnostics
A fatty liver usually falls into a ultrasonography enlargement and increased echogenicity compared with the kidney as well as a crude form or in a magnetic resonance imaging. If for any other reason, a biopsy of the liver is performed, can also be ensured histologically fatty liver. Laboratory tests can result in no positive proof, however, often fall on slightly elevated transaminases and elevated γ-GT. The severity can be determined by special Kernspintomographie- or elastography methods.
Therapy
A fatty liver (without signs of liver inflammation) has little clinical significance. However, since they can go in a steatohepatitis and it may be an early sign of metabolic syndrome, especially nutritional therapeutic measures should be taken. This often is enough alcohol abstinence and a balanced, healthy diet in order to completely rückzubilden the fat deposits. In the presence of a strong excess weight (obesity) a reduced-calorie diet should be considered prophylactically.