Hyperlipidemia
Introduction
Introduction to hyperlipidemia Hyperlipidemia refers to high blood lipid levels, which can directly cause diseases that seriously endanger human health, such as atherosclerosis, coronary heart disease, and pancreatitis. Due to fat metabolism or abnormal operation, one or more lipids in plasma are higher than normal called hyperlipidemia. Lipid insoluble or slightly soluble in water must be combined with protein to exist in the form of lipoprotein. Therefore, hyperlipidemia often occurs. It is hyperlipoproteinemia, which is characterized by hypercholesterolemia and hypertriglyceridemia. basic knowledge The proportion of sickness: 0.46% Susceptible people: good for middle-aged and elderly Mode of infection: non-infectious Complications: coronary heart disease, diabetes, fatty liver
Cause
Hyperlipidemia
Secondary elevated levels of serum lipoproteins (30%):
Blood lipids mainly include cholesterol (or total cholesterol TC) and triglycerides, which exist in a non-free state in the blood circulation, and protein transports into a macromolecular transport such as lipoproteins. The main lipoprotein classification - chylomicrons, very low Density (pre-beta) lipoprotein (VLDL), low density (-) lipoprotein (LDL), and high density (a-) lipoprotein (HDL) -- these proteins are closely related, and often In terms of physicochemical properties (such as electrophoretic mobility and density after ultracentrifugation), the major lipoproteins in the blood are transported to triglycerides, which are the largest lipoprotein carriers, and exogenous triglycerides From the thoracic duct to the venous system, in fat capillaries and muscle tissue, 90% of the chylomicron is transported through a specific set of esterases, and the chylomicrons are hydrolyzed into fatty acids and glycerol into the fat cells and muscle cells. Utilization or storage, this lipase rapidly degrades endogenous triglycerides in VLDL, causing loss of triglyceride and apoprotein in medium density lipoprotein (IDL), and separation of IDL by 2 to 6 hours. Triglyceride and further degrade into LD The half-life of L, LDL in plasma is 2 to 3 days, and VLDL is the main source of plasma LDL.
Hyperlipidemia (40%):
Excessive or clearing disorder caused by VLDL and excessive conversion of VLDL into LDL. Obesity, diabetes, alcohol overdose, nephrotic syndrome or genetic defects can cause excessive production of VLDL in the liver, and LDL and TC are also often associated with high blood triglycerides. Ester-associated, LDL clearance disorder is associated with structural defects in apoB. In addition, clearance disorders may also be due to decreased LDL receptor number or dysfunction (reduced viability), which may be due to genetic or dietary factors, LDL receptor protein structure Molecular defects are a common genetic cause of LDL receptor dysfunction - a common mechanism of gene defects is described below.
Prevention
Hyperlipidemia prevention
To avoid the harm of hyperlipidemia, there are two main prevention and treatment principles.
First, establish good living habits, quit smoking, stop drinking, strengthen physical exercise, choose light and moderate sports activities suitable for me, combine work and rest, relieve all kinds of ideological concerns, feel comfortable, and maintain health.
The second is to use diet therapy to limit the excessive intake of high-cholesterol foods, such as animal fat, animal brain, internal organs, cream, soft body, shellfish intake, diet structure should be rationally allocated, the proportion of protein is 15%, 20% fat, 65% carbohydrates (sugar), supplemented with high-quality protein, eat fresh vegetables and eat appropriate fruits, eat more eggplant, onions, hawthorn, tomatoes, soy products, soybeans, corn, walnuts and Milk and so on.
Complication
Hyperlipidemia complications Complications, coronary heart disease, diabetic fatty liver
If the blood lipids are too much, it is easy to cause "blood thickening", deposit on the blood vessel wall, and gradually form small plaques (which we often call "atherosclerosis"). These "plaques" increase, enlarge, and gradually block blood vessels. Slow blood flow, severe blood flow is interrupted, if this happens in the heart, it will cause coronary heart disease; in the brain, there will be a stroke; if the blood vessels in the fundus are blocked, it will lead to decreased vision and blindness; if it occurs In the kidney, it will cause renal arteriosclerosis, renal failure; in the lower limbs, limb necrosis, ulceration, etc., in addition, hyperlipidemia can cause high blood pressure, induce gallstones, pancreatitis, aggravate hepatitis, leading to male sexual dysfunction Diseases such as Alzheimer's disease, the latest research suggests that hyperlipidemia may be related to the onset of cancer.
Blood lipids and coronary heart disease
Rejection statistics, the mortality rate of cardiovascular and cerebrovascular diseases has exceeded 1/2 of the total mortality rate of the population. Coronary heart disease is also called coronary atherosclerotic heart disease. The coronary artery is an artery that supplies blood to the heart. Due to excessive fat deposition, Causes arteriosclerosis, obstructs blood flow, causes cardiac ischemia, and a series of symptoms, namely coronary heart disease, causes risk factors for coronary heart disease: hyperlipidemia, smoking, diabetes, obesity, high blood pressure, lack of physical activity, excessive mental stress, Family history of coronary heart disease, oral contraceptives, etc. Among them, hyperlipidemia is one of the important risk factors for coronary heart disease. Regulating blood lipids is the most basic treatment for coronary heart disease: serum total cholesterol level drops by 1%, the incidence of coronary heart disease decreases. 2%, as long as there is coronary heart disease, whether your blood lipids are high or not high, you should take long-term lipid-lowering drugs, because long-term lipid-lowering treatment can reduce the incidence of coronary heart disease angina, myocardial infarction and mortality.
Relationship between blood lipids and cerebral infarction
When the blood cholesterol is increased, it is easy to form atherosclerotic plaques. These plaques accumulate in the arterial wall, narrowing the arterial cavity, blocking the flow of blood into the corresponding parts, causing kinetic energy defects, which cause cerebral infarction when it occurs in the cerebral blood vessels. Medical proof Long-term lipid-lowering treatment can not only treat cerebral infarction, but also prevent cerebral infarction, lipid-lowering therapy and stroke: There are many reasons for stroke, such as high blood pressure, high blood fat, smoking, drinking, obesity, advanced age, diabetes, blood diseases, etc. Among them, hyperlipidemia and cerebral atherosclerosis are important risk factors for cerebral infarction. Many studies have shown that long-term lipid-lowering treatment can significantly reduce the incidence and disability of stroke, so clinicians treat hyperlipemia. More and more attention.
Symptom
Hyperlipidemia Symptoms Common symptoms Obesity hand cramps severe obesity serum HDL-C... Acute lower extremity ischemic angiography abnormal atherosclerosis Diabetes hyperuricemia
First, medical history, symptoms:
Primary people are seen in children, secondary cases are more likely to develop after the age of 20, most people are asymptomatic only found during physical examination, but also early coronary heart disease and other atherosclerotic diseases such as stroke, peripheral vascular disease, often With obesity, impaired glucose tolerance (or diabetes), hyperinsulinemia, hyperuricemia, acute pancreatitis can occur, often appear in the upper, lower eyelid or sacral xanthoma in the extensor tendon of the limb, such as the olecranon , heel, heel, with pain and tenderness when accompanied by tendonitis.
Second, physical examination found:
There may be signs of obesity, peripheral neuritis or atherosclerotic disease, diabetes and the like.
Examine
Hyperlipidemia test
1, the determination of blood lipid profile
Fasting TC, TG, LDL-C, HDL-C.
2, to determine the presence or absence of chylomicrons in plasma
An easy method is to place the plasma in a refrigerator at 4 ° C overnight and then observe if the plasma has a "creamy" top layer.
3. Plasma low density lipoprotein (LDL-C) concentration
Plasma cholesterol levels may vary by ±10% within 1 to 2 weeks, and laboratory variations are tolerated within 3%.
4. Special examination about lipid metabolism
(1) Apolipoprotein assay Determination of plasma ApoB and ApoAI levels is important for predicting the risk of coronary heart disease.
(2) In vivo lipoprotein metabolism test In addition, gene DNA mutation analysis, lipoprotein-receptor interaction, and measurement of lipoprotein lipase, hepatic lipase, cholesterol lipase, and synthetase can be performed.
5, other inspections
Familial mixed hyperlipidemia and familial hypertriglyceridemia have insulin resistance, and plasma insulin levels are elevated, which can be clinically characterized as impaired glucose tolerance; type III hyperlipoproteinemia often has diabetes; familial Mixed hyperlipidemia may be associated with hyperuricemia; patients with type III hyperlipoproteinemia may be associated with hypothyroidism.
Diagnosis
Hyperlipidemia diagnosis
diagnosis
Regarding the diagnostic criteria for hyperlipidemia, there is currently no uniform method at home and abroad. It has been previously thought that plasma total cholesterol concentration > 5.17 mmol / L (200 mg / dl) can be determined as hypercholesterolemia, plasma triglyceride concentration > 2.3mmol / L (200mg / dl) for hypertriglyceridemia. Due to factors such as the different populations tested and the differences in test methods used, the diagnostic criteria for hyperlipidemia were different. However, in order to prevent and treat atherosclerosis and coronary heart disease, the appropriate plasma cholesterol level should be determined according to the risk of cardiovascular and cerebrovascular diseases in the future. The higher the risk, the lower the appropriate plasma cholesterol level should be.
The new standard recommends starting drug therapy at an LDL-C concentration of >130 mg/dl. The LDL-C concentration is <100 mg/dl. If the risk of cardiovascular and cerebrovascular disease is high in the future, drug therapy should be started earlier. Take more stringent treatment goals. Low HDL-C concentration is a risk factor for coronary heart disease, <40 mg/dl. The standard for the classification of triacylglycerols is lowered, and the increase is emphasized.
Differential diagnosis
It should be differentiated from secondary hyperlipoproteinemia such as diet, diabetes, hypothyroidism, kidney disease, biliary obstruction, and biliary cirrhosis.
