Hyperlipoproteinemia type II
Introduction
Introduction to hyperlipoproteinemia type II Hyperlipoproteinemia type II is classified into hyperlipoproteinemia type IIa and hyperlipoproteinemia type IIb. Hyperlipoproteinemia type IIa: also known as familial hypercholesterolemia, hyperlipoproteinemia and the like. It is an inherited metabolic disorder characterized by high-fat -proteinemia, and due to -lipoprotein (LDL) receptor deficiency or insufficiency, resulting in decreased intracellular cholesterol metabolism, familial, autosomal Sexual inheritance, pure zygote serum cholesterol level is greater than 400mg / L. Hyperlipoproteinemia type IIb: also known as high -lipoproteinemia and high pre-beta-lipoproteinemia, hyperlipidemia and hypercholesterolemia, hypertriglyceridemia and hypercholesterolemia Symptoms, which are characterized by a significant increase in - and pre-beta-lipoproteins. Many patients do not have a clear family history. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: hyperuricemia
Cause
Hyperlipoproteinemia type II etiology
High cholesterol in diet (25%):
Generally, people in western countries consume 400 mg/d of cholesterol, while those with low cholesterol have an intake of 200 mg/d. Cholesterol intake increased from 200 mg/d to 400 mg/d, which increased blood cholesterol by 0.13 mmol/l (5 mg/dl). The mechanism may be related to increased cholesterol in the liver and decreased synthesis of ldl receptors.
High dietary saturated fatty acids (20%):
One of the main causes of elevated cholesterol is higher dietary intake of saturated fatty acids. A typical Westerner consumes about 14% of the total calories per day, and the ideal amount should be 7%. It is generally believed that saturated fatty acid intake accounts for 14% of total calories (ie, 7% more), which can cause blood cholesterol to increase by about 0.52 mmol/l (20 mg/dl), most of which is ldl-c. There is data indicating that saturated fatty acids inhibit the activity of the ldl receptor. Although the exact mechanism is not clear, it may be related to the following five aspects: 1 inhibition of cholesterol ester synthesis in the liver; 2 promotion of inactive non-esterified cholesterol into the active pool; 3 promotion of regulatory oxidative steroid formation; 4 Decrease the cell surface ldl receptor activity; 5 reduce the affinity of ldl to the ldl receptor.
Defects in metabolic disorders (20%):
Hyperlipoproteinemia Type IIa: Defects in metabolic disorders such as LDL receptor defects, as evidenced by fibroblast culture.
Hyperlipoproteinemia type IIb: It is still unclear.
Pathogenesis
Hyperlipoproteinemia type IIa: The metabolic rate of serum LDL in healthy people is about 45% per day, while homozygous patients lack active LDL receptors, only 17%, and heterozygous about 30%, because LDLS cannot enter cells, so it cannot be performed. Intracellular metabolism, LDLS accumulates a large number of aged LDLS in the plasma to induce macular tumors, nodular xanthoma and atherosclerosis (coronary arteriosclerosis and peripheral arteriosclerosis).
Hyperlipoproteinemia type IIb: It is still unclear.
Prevention
Hyperlipoproteinemia type II prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease. Extensive and repeated health education through a variety of ways, promoting scientific diet, balanced diet, regular physical exercise, prevention of obesity, smoking cessation, alcohol restriction, and health education and publicity education on prevention and treatment of chronic diseases such as cardiovascular disease, obesity and diabetes Combine to keep the blood lipids in the crowd at an appropriate level. In addition, regular health checks can also help early detection of abnormal bleeding and should be treated promptly.
Complication
Hyperlipoproteinemia type II complications Complications hyperuricemia
In the case where the supply of exogenous triglyceride is reduced, it is converted to type IV. Increased endogenous triglyceride synthesis in the liver, as well as exogenous chylomicronemia, decreased lipase levels in some patients. The skin manifests as rash xanthomas. The incidence of arteriosclerosis is unclear. There may be hepatosplenomegaly, abdominal cramps, hyperuricemia and hyperglycemia. Triglycerides exceeding 1000 mg/dl can cause acute pancreatitis. Patients who do not receive treatment can develop coronary sclerosing heart disease, recurrent pancreatitis.
Symptom
Hyperlipoproteinemia type II symptoms common symptoms nodular sclerosis coronary embolism atherosclerosis
Hyperlipoproteinemia Type IIa: Pure zygotes develop symptoms in early childhood, and heterozygous zygotes often occur between the ages of 20 and 50. Typical symptoms include jaundice, nodular xanthoma, jaundice, and atherosclerosis. Arteriosclerosis mainly occurs in the coronary arteries, serum is transparent, cholesterol and -lipoprotein are significantly increased, apo- and LDL cholesterol are elevated, and triglycerides are normal.
Hyperlipoproteinemia type IIb: clinical manifestations similar to hyperlipoproteinemia type IIa, patients often obese, rash xanthomas can occur, serum from clear or turbid, cholesterol, triglycerides, LDL and pre-- Both lipoprotein (VLDLS) were elevated, Apo-B and apo-CIII were elevated, and only by serum electrophoresis analysis and ultracentrifugation were identified with hyperlipoproteinemia type III.
Examine
Hyperlipoproteinemia type II examination
Hyperlipoproteinemia type IIa, serum clear, cholesterol and -lipoprotein are significantly increased, apo- and LDL cholesterol are elevated, triglycerides are normal, hyperlipoproteinemia type IIb, serum is clear or turbid, cholesterol, Triglycerides, LDL and pre--lipoprotein (VLDLS) were elevated, Apo-B and apo-CIII were elevated, and only differentiated by hyperlipoproteinemia type III by serum electrophoresis analysis and ultracentrifugation.
Diagnosis
Type II diagnosis and identification of hyperlipoproteinemia
diagnosis
According to the clinical manifestations, the characteristics of skin lesions, serum electrophoresis analysis and ultracentrifugation can be diagnosed.
Differential diagnosis
Identification with type III hyperlipoproteinemia.
