Fatty Liver

　　Obesity, type 2 diabetes, hyperlipidemia, and other factors alone or in combination can become susceptible factors for non-alcoholic fatty liver disease, while excessive drinking is a susceptible factor for alcoholic fatty liver disease. The pathogenic factors of fatty liver include chemical factors, nutritional factors, endocrine and metabolic factors, biological pathogenic factors, and genetic factors.

　　1. Chemical pathogenic factorsIncluding chemical toxins (yellow phosphorus, arsenic, lead, benzene, carbon tetrachloride, chloroform, etc.), drugs (methotrexate, tetracycline, amiodarone, glucocorticoids, etc.), alcohol, etc., excessive drinking has always been the most common cause of fatty liver and liver cirrhosis in Europe and America.

　　2. High-calorie diet and obesityHigh-calorie diet and obesity are one of the most common factors causing fatty liver in recent years, while protein and calorie deficiency are another important cause of fatty liver.

　　3. Biological factorsIncluding pathogenic microorganisms such as viruses and bacteria, as well as parasites, these pathogenic factors mainly cause liver cell变性坏死 and inflammatory cell infiltration, leading to fatty liver of the liver cells.

　　4. Genetic factorsThrough the mutation of genetic material genes or chromosomal abnormalities, diseases can be caused directly, leading to congenital metabolic liver disease. Among the genetic diseases such as hepatolenticular degeneration, galactosemia, glycogen storage disease, and fructose intolerance, they can cause macrovesicular fatty liver, while congenital defects in urea cycle enzymes and genetic defects in mitochondrial fatty acid oxidation can cause microvesicular fatty liver.

　　Common complications of fatty liver include:

　　Due to vitamin deficiency, anemia, glossitis, peripheral neuritis, and symptoms of the nervous system may be accompanied.

　　Liver enlargement is common, ranging from mild to severe enlargement, but it is also possible to see severe fatty liver without liver enlargement in clinical practice.

　　Severe fatty liver patients may have ascites and lower limb edema, and other symptoms may include spider veins, gynecomastia, testicular atrophy, impotence in men, and amenorrhea, infertility in women, and so on.

　　Mild fatty liver may have no clinical symptoms at all, especially in the elderly due to overeating or high-fat diet, which is clinically known as 'latent fatty liver'. Moderate or severe patients, especially those with a long course of disease, have more obvious symptoms. Common symptoms include fatigue, loss of appetite, right hypochondrial pain, nausea, abdominal distension, and other liver dysfunction symptoms. Abdominal pain may be accompanied, mainly right upper quadrant pain, occasionally middle upper quadrant pain, accompanied by tenderness, and in severe cases, rebound pain and fever, increased white blood cell count, resembling the symptoms of acute abdomen.

　　Non-alcoholic fatty liver disease has an insidious onset, a slow progression, and is often asymptomatic. A few patients may have symptoms such as fatigue, mild discomfort in the upper right abdomen, pain in the liver area, or abdominal distension. Severe fatty hepatitis can cause symptoms such as jaundice, loss of appetite, nausea, vomiting, and so on. Routine physical examinations may reveal liver enlargement in some patients. When it progresses to liver cirrhosis with decompensation, its clinical manifestations are similar to those caused by liver cirrhosis due to other reasons. Alcoholic fatty liver patients generally have good general condition, often have no symptoms or mild symptoms, and may have symptoms such as fatigue, loss of appetite, mild pain or discomfort in the upper right abdomen, and so on.

　　The occurrence of fatty liver is mainly due to an unreasonable diet structure and excessive alcohol consumption, therefore, to prevent the occurrence of this disease, a reasonable and balanced diet structure and a regular diet should be established. Do not drink alcohol excessively, drink light tea regularly. Insist on appropriate physical exercise. Actively treat the primary disease.

　　The three meals a day should be properly balanced, with a combination of coarse and fine grains, and a balanced diet. Staple foods should not be too refined, and some coarse grains such as oatmeal, corn, sweet potatoes, and soy products should be eaten in moderation. These foods contain a high amount of linoleic acid, calcium, selenium, lecithin, vitamin E, and a lot of fiber, which can reduce serum cholesterol and triglycerides, neutralize the excess acid produced in the body due to excessive consumption of meat and eggs, maintain the acid-base balance in the human body, and can also expel excessive fat, sugar, and toxins from the intestines, thereby reducing fat; ensure an adequate supply of vegetables and fruits to meet the needs of vitamins and dietary fiber in the body; fruits contain more sugar, so the amount of consumption should be appropriate.

　　Restrictive diet means controlling high-energy, high-sugar, and high-fat foods. The first step is to control energy intake, aiming to reduce weight to the standard weight, ensuring that energy expenditure is higher than energy intake. Eat more vegetables and limit staple foods, quit smoking and limit alcohol consumption, especially to limit fatty foods; do not eat or eat less sweet foods, fried foods, and broths such as chicken soup, fish soup; do not eat high-cholesterol foods such as animal internal organs and egg yolks, to promote the oxidation and consumption of excess fat in the body, thereby reducing weight.

　　The diagnosis of fatty liver mainly relies on liver ultrasound examination and serological examination to clarify liver function. Common laboratory tests include:
　　1. Serological Examination
　　Serum transaminase and γ-glutamyltransferase levels are normal or slightly to moderately elevated (less than 5 times the upper limit of normal), and usually the increase in alanine aminotransferase (ALT) is predominant.
　　2. Imaging Examination
　　Type B ultrasound is an important and practical means for diagnosing fatty liver disease, with an accuracy rate of about 70% to 80% in diagnosing fatty liver disease. CT scanning shows a general decrease in liver density, and the CT density ratio of liver/spleen ≤1 can clearly diagnose fatty liver disease. The degree of fatty liver disease can be judged according to the CT density ratio of liver/spleen.
　　3. Pathological Examination
　　Liver biopsy is still the main method for diagnosing non-alcoholic fatty liver disease, and it is of great significance in distinguishing focal fatty liver from liver tumors, certain rare diseases such as hemochromatosis, cholesterol ester storage disease, and glycogen storage disease, and it is also the most sensitive and specific method for judging the prognosis.

　　A reasonable diet for patients with fatty liver should be a low-fat diet, choosing high-protein, moderate calories, and low-carbohydrate diet. Obese people should create a negative energy balance state on the basis of ensuring the basic needs of the body's protein and various nutrients. For malnutrition fatty liver, a diet with high protein, sufficient carbohydrates and fats should be followed.

　　Controlling diet is very important for the prevention and treatment of hyperlipidemia. Low-fat diet advocates lightness, basically vegetarian, but it is not advisable to eat only vegetarian food for a long time. It is advisable to limit the intake of high-fat and high-cholesterol foods such as red meat (pork, beef, lamb), animal brains, the skin of poultry, yolks, crab roe, fish roe, chicken liver, butter, etc. Limit the intake of fat to 30-50 grams per day. Healthy people should have less than 300 milligrams of cholesterol intake per day, and patients with coronary heart disease and hyperlipidemia should have less than 200 milligrams of cholesterol intake per day. Sugar-containing foods should also be limited, and sweets and snacks should not be eaten. Eat more vegetables and fruits. Vegetable oils such as soybean oil, peanut oil, rapeseed oil, and sesame oil are recommended. Protein intake should be mainly from white meat, such as poultry and scale fish. Eat moderately, and the amount of food should be enough to feel hungry half an hour before the next meal.

　　1. Low-fat Diet

　　(1) Limit daily fat intake to less than 40g, and avoid fried foods, fatty meats, lard, and snacks with high fat content.

　　(2) Cooking methods such as steaming, braising, boiling, and stewing can be used to improve the color, smell, and taste of food with less or no oil.

　　(3) You can choose skimmed milk or strained meat broth to remove oil, but avoid using oil cakes, cream candies, and nuts.

　　2. Low-cholesterol Diet

　　(1) Limit cholesterol intake to 300mg per day.

　　(2) Mainly consume rice, wheat, vegetables, and fruits, and you can choose low-cholesterol foods such as milk, eggs, lean meat, duck meat, grass carp, crucian carp, bighead carp, sea cucumber, and soy products.

　　(3) Foods containing cholesterol, such as animal organs, yolks, brains, fish roe, sardines, and crab roe, should be used as little as possible.

　　(4) It is not advisable to use animal oil; vegetable oil should be used instead.

　　The main method of Western medicine in the treatment of fatty liver is to control risk factors and prevent the further progression of fatty liver. For severe fatty liver patients, drug treatment can be considered.

　　(1) Treatment for Risk Factors

　　If the causes of non-alcoholic fatty liver disease can be controlled, simple fatty liver disease and fatty hepatitis can be reversed and even completely restored, which is the most important measure for treating non-alcoholic fatty liver disease. Weight loss and exercise can improve insulin resistance, and are the best measures for treating obesity-related non-alcoholic fatty liver disease. Limiting calorie and fat intake can gradually reduce weight, but attention should be paid to the possibility of exacerbating liver damage due to rapid weight loss, and weight and liver function should be monitored during the weight loss process. Adequate exercise and persistence are required. For those with hyperlipidemia, dietary restriction and structural adjustment are the main measures. The use of hypolipidemic drugs should be cautious, as they can drive lipids to concentrate more in the liver for metabolism, often leading to further damage to liver cells. It is generally believed that hypolipidemic drugs are only used for those with significantly elevated blood lipids, and liver function should be closely monitored during the medication process. Diabetic patients should actively control blood sugar levels.

　　(2) Medication

　　Currently, the drugs used in clinical treatment of non-alcoholic fatty liver disease are not certain in efficacy. Phosphatidylcholine, S-adenosylmethionine, and other substances can be tried due to few adverse reactions. Vitamin E has antioxidant effects, can reduce oxidative stress, and is recommended for routine use in the treatment of fatty liver.

　　(3) Abstaining from Alcohol

　　Abstaining from alcohol is the key to treating alcoholic liver disease. For those with only alcoholic fatty liver, after 4-6 weeks of abstinence from alcohol, the progression of fatty liver can stop, and it can eventually return to normal. Complete abstinence from alcohol can gradually alleviate the clinical symptoms, elevated serum transaminase levels, and pathological changes of alcoholic hepatitis, and significantly improve the survival rate of patients with alcoholic hepatitis, fibrosis, and liver cirrhosis.

　　(4) Nutritional Support Therapy

　　Chronic alcoholics, alcohol replaces the calories provided by food, so insufficient intake of protein and vitamins leads to malnutrition. Therefore, patients with alcoholic liver disease require good nutritional support, and a high-calorie, high-protein, low-fat diet should be given on the basis of abstinence from alcohol, and a variety of vitamins (such as vitamin B, C, K, and folic acid) should be supplemented.