What Is Non-Alcoholic Fatty Liver Disease?

Non-alcoholic fatty liver disease (NAFLD) refers to a clinicopathological syndrome that is characterized primarily by excessive deposition of intracellular fat in liver cells caused by alcohol and other well-defined liver damage factors. It is an acquisition closely related to insulin resistance and genetic susceptibility. Metabolic Stress Liver Injury. Including simple fatty liver (SFL), non-alcoholic steatohepatitis (NASH) and related liver cirrhosis. With the epidemic trend of globalization of obesity and its related metabolic syndrome, non-alcoholic fatty liver disease has become an important cause of chronic liver disease in developed countries such as Europe and the United States and in rich areas in China. The prevalence of NAFLD in ordinary adults is 10% to 30%. Among them, 10% to 20% are NASH, and the incidence of cirrhosis in the latter is as high as 25% within 10 years.

Basic Information

Western Medicine Name: Nonalcoholic fatty liver disease
English name: nonalcoholic fatty liver disease, NAFLD
Affiliated Department: Internal Medicine-Gastroenterology
Disease site: liver

The main symptoms: No conscious symptoms, mild fatigue, loss of appetite, bloating, belching, fullness of liver area, etc.
Contagious: Non-contagious
Whether to enter health insurance: no

Causes of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is divided into two categories, primary and secondary. The former is related to insulin resistance and genetic susceptibility, while the latter is caused by some special reasons. Overweight caused by excessive nutrition and overweight, fatty liver related to metabolic syndrome such as obesity, diabetes, hyperlipidemia, and cryptogenic fatty liver belong to the category of primary non-alcoholic fatty liver disease; and nutrition Fatty liver caused by poor, total parenteral nutrition, sharp weight loss after bariatric surgery, drug / environment, and industrial poisoning are among the categories of secondary non-alcoholic fatty liver disease.

Pathology of nonalcoholic fatty liver disease

According to the degree of pathological changes and whether the diseased liver tissue is accompanied by inflammation and fibrosis, non-alcoholic fatty liver disease can be divided into: simple fatty liver, NASH, NASH-related cirrhosis.

Simple fatty liver

According to the extent of hepatocyte steatosis occupying the range of liver tissue specimens obtained, it is divided into 4 degrees (F0 ~ 4): F0 <5% hepatocyte steatosis; F1 5% ~ 30% hepatocyte steatosis; F2 30% ~ 50 % Liver cell steatosis; F3 50% to 75% liver cell steatosis; F4 more than 75% liver cell steatosis.

2. Non-alcoholic steatohepatitis

It refers to hepatocyte inflammation that occurs on the basis of hepatocyte steatosis. The degree of fatty liver is divided into 4 degrees (F0 ~ 4); the degree of inflammation is divided into 3 grades (G0 ~ 3)

3. Non-alcoholic steatohepatitis-related cirrhosis

The structure of the hepatic lobules was completely destroyed, replaced by pseudolobular formation and extensive fibrosis, and generally nodular cirrhosis. According to the presence of interfacial hepatitis with fibrous septum, it can be divided into active and resting.

Clinical manifestations of non-alcoholic fatty liver disease

1. Most patients with fatty liver have no conscious symptoms. Some patients may have nonspecific symptoms and signs such as fatigue, indigestion, dull pain in the liver area, and hepatosplenomegaly.

2. May have overweight and / or visceral obesity, increased fasting blood glucose, dyslipidemia, hypertension and other metabolic syndrome related symptoms.

Nonalcoholic fatty liver disease examination

1.B ultrasound diagnosis

(1) The near-field echo in the liver area is diffusely enhanced (stronger than the kidney and spleen), and the far-field echo is gradually attenuated.

(2) The structure of intrahepatic ducts is not clear.

(3) Mild to moderate swelling of the liver with rounded corners.

(4) Color Doppler blood flow imaging indicates that the intrahepatic blood flow signal is reduced or difficult to display, but the intrahepatic blood vessels are normal.

(5) The envelope of the right lobe of the liver and the diaphragm's echo are unclear or incomplete.

Those with one of the above items 1 and 2 to 4 are mild fatty liver; those with two of the above items 1 and 2 to 4 are moderate fatty liver; those with the above items 1 and 2 Two of 4 and 5 are severe fatty liver.

2.CT diagnosis

Diffuse liver density decreases, liver / spleen CT ratio 1.0 but greater than 0.7 is mild; liver / spleen CT ratio 0.7 but large stem 0.5 is moderate; liver / spleen CT ratio 0.5 is severe.

3. Liver aspiration biopsy of liver.

Diagnosis of non-alcoholic fatty liver disease

The diagnosis of non-alcoholic fatty liver disease requires the following three conditions:

1. No drinking history or alcohol content less than 140g per week (women <70g).

2. Excludes viral hepatitis, drug-induced liver disease, total parenteral nutrition, hepatolenticular degeneration and other specific diseases that can lead to fatty liver.

3. Histological changes of liver biopsy meet the pathological diagnostic criteria of fatty liver disease.

Differential diagnosis of non-alcoholic fatty liver disease

Need to exclude alcoholic liver disease, chronic hepatitis C, autoimmune liver disease, hepatolenticular degeneration, and other specific diseases that can cause fatty liver; and exclude drugs (tamoxifen, amiodarone, methotrexate, sugar Corticosteroids), total parenteral nutrition, inflammatory bowel disease, hypothyroidism, Cushing's syndrome, beta lipoproteinemia, and fatty liver associated with congenital insulin resistance syndrome.

Treatment of non-alcoholic fatty liver disease

Basic treatment

Develop reasonable energy intake and dietary adjustments, moderate aerobic exercise, and correct poor lifestyle and behavior.

2. Avoid aggravating liver damage

Prevent sharp weight loss, drug abuse, and other factors that may cause worsening liver disease.

3. Lose weight

All patients with overweight, visceral obesity, and non-alcoholic fatty liver disease who gain weight rapidly in the short term need to change their lifestyle to control their weight and reduce their waist circumference.

4. Insulin sensitizer

Patients with type 2 diabetes, impaired glucose tolerance, increased fasting blood glucose, and visceral obesity may consider the use of metformin and thiazolidinediones to improve insulin resistance and control blood sugar.

5. Hypolipidemic drugs

Dyslipidemia After basic treatment and application of weight-loss and hypoglycemic drugs for more than 3 to 6 months, those who still have mixed hyperlipidemia or hyperlipidemia combined with more than 2 risk factors need to consider adding fibrates, statins or Blood lipid-lowering drugs such as probucol.

6. Drugs for liver disease

Nonalcoholic fatty liver disease with liver dysfunction, metabolic syndrome, 3 to 6 months after basic treatment is still ineffective, and liver biopsy confirmed that NASH and chronic progress of the course can be treated with drugs for liver disease For treatment, anti-oxidation, anti-inflammatory, anti-fibrosis, related drugs such as polyene phosphatidylcholine, vitamin E, silymarin, and ursodeoxycholic acid can be reasonably selected according to drug performance, disease activity and disease stage, but not at the same time. Application of multiple drugs.

Prognosis of non-alcoholic fatty liver disease

Most non-alcoholic fatty liver diseases have a good prognosis, and the liver histology progresses slowly or even at rest, and the prognosis is relatively good. Even if some patients have been complicated with steatohepatitis and liver fibrosis, if they can be diagnosed and treated in time, liver histological changes can still be reversed. Rare fat cysts rupture with fat embolism and die. A small number of patients with steatohepatitis progress to cirrhosis, and once cirrhosis occurs, the prognosis is poor. For most patients with fatty liver, sometimes the goal of controlling weight and blood sugar, lowering blood lipids, and promoting liver histological reversal can be achieved through non-drug treatments such as a moderate diet and adherence to moderate aerobic exercise.