OVERVIEW
Mixed hyperlipidemia is a clinical type of hyperlipidemia that refers to high serum levels of both total cholesterol and triglycerides, i.e., total cholesterol > 5.72 mmol/L (220 mg/dL) and triglycerides > 1.84 mmol/L (160 mg/dL). Patients with mixed hyperlipidemia are more dangerous and difficult to treat than those with elevated cholesterol alone. It is difficult to achieve blood lipid levels with a single lipid-lowering drug, and a combination of lipid-lowering drugs with different mechanisms is often needed. Long-term dyslipidemia can lead to atherosclerosis and increase the morbidity and mortality of cardiovascular and cerebrovascular diseases, which not only brings great mental pain to patients, but also increases the economic burden of families and society. Therefore, prevention and treatment of dyslipidemia is of great significance to prolong life and improve quality of life.
Questions you may be concerned about
What does mixed hyperlipidemia mean
Mixed hyperlipidemia is a type of hyperlipidemia in which total cholesterol and triglycerides are elevated at the same time, which can be more harmful to the human body and requires active treatment.
Mixed hyperlipidemia is a clinical classification of hyperlipidemia that refers to the simultaneous presence of serum total cholesterol levels ≥6.2 mmol/L and triglyceride levels ≥2.3 mmol/L, both above the normal range.
Compared with simple hypercholesterolemia or hypertriglyceridemia, mixed hyperlipidemia is more harmful to the human body, resulting in a higher risk of complications such as atherosclerosis or cardiovascular and cerebral vascular diseases, and is more difficult to treat, and needs to be under the guidance of the doctor in conjunction with their own conditions, and active control of blood lipids.
Causes
1. Primary dyslipidemia
The etiology of familial mixed hyperlipidemia is not well understood, and most of the current research has been conducted on genetic defects and metabolic abnormalities. The prominent feature of this disease is that patients with different types of hyperlipoproteinemia are found in the same family, and there is a positive family history of myocardial infarction occurring in people under 60 years of age. Most of the primary dyslipidemia is of unknown cause and is sporadic. Clinically, it can often occur together with obesity, hypertension, coronary heart disease, diabetes mellitus and other diseases, which is known as metabolic syndrome. Dyslipidemia may be involved in the development of the above diseases, or at least be a risk factor for them, or have a common basis for the development of the above diseases.
2. Secondary dyslipidemia
Systemic diseases such as diabetes mellitus, hypothyroidism, hepatic and renal diseases, systemic lupus erythematosus and multiple myeloma can cause secondary dyslipidemia. Certain medications such as thiazide diuretics, beta-blockers, and long-term use of glucocorticoids can also lead to elevated blood lipids.
Symptoms
1. Xanthomas, early-onset corneal rings and fundus changes of lipemia: Xanthomas are a kind of limited skin elevation, yellow or brown in color, the most common is flat xanthoma around the eyelids. Early-onset corneal rings appear under the age of 40. Severe hypertriglyceridemia can produce lipemic fundus changes.
2. Atherosclerosis is caused by the deposition of lipids in blood vessels, leading to early-onset and rapidly progressive cardiovascular and peripheral vascular disease. Some familial mixed hyperlipidemia can occur before puberty, coronary heart disease, or even myocardial infarction. Most patients with dyslipidemia do not have any symptoms or abnormal signs, but are found during routine biochemical tests.
Tests
1. Biochemical examination is the most commonly used laboratory test to determine the levels of total cholesterol, total triglycerides, LDL cholesterol and HDL cholesterol in fasting condition.
2. Ultracentrifugation technique: This method is the gold standard for the typing of dyslipidemia, but the operation is complicated and the equipment is expensive, which is difficult to be done in general clinical laboratories.
3. Lipoprotein electrophoresis: the results of this method are more variable, and it is not commonly used nowadays.
Diagnosis
The diagnosis can be clarified through the measurement of blood lipids, ApoE phenotype or ApoE genotype.
Treatment
1. Therapeutic lifestyle changes
Low-fat, low-salt, low-sugar diet, increase the intake of polyunsaturated fatty acids; weight control; increase regular physical activity; quit smoking and alcohol.
2. Drug therapy
Statins, such as atorvastatin, resuvastatin, pravastatin, etc., are indicated for hypercholesterolemia and mixed hyperlipidemia with elevated cholesterol. These drugs are the most widely used lipid-lowering drugs in clinical practice. (ii) Fenofibrate, benzafibrate, etc. The indications are hypertriglyceridemia and mixed hyperlipidemia with mainly elevated triglycerides. (iii) Niacin analogs such as nicotinic acid, acipimox, etc.; acid chelators such as colesevelam; ezetimibe, etc.; the indications for the above three classes of drugs are hypercholesterolemia and mixed hyperlipidemia with predominantly elevated cholesterol. Regarding the choice of lipid-regulating drugs, statins are preferred for patients with mixed hyperlipidemia if cholesterol and LDL cholesterol are predominantly elevated; fibrates are preferred if triglycerides are predominantly elevated; and drugs can be used in combination if cholesterol, triglycerides, and LDL cholesterol are all significantly elevated. Combined use of statins and fibrates or niacin can significantly reduce lipid levels, but increase the possibility of myopathy and hepatotoxicity, which should be highly valued.
3. Other therapeutic measures
Blood purification, surgical treatment, gene therapy.
Prognosis
Long-term high levels of blood lipids are associated with a high risk of atherosclerosis, which in turn leads to the development of serious cardiovascular and cerebrovascular diseases, so lipid regulation is of great clinical importance. The treatment of this disease is generally long-term, even lifelong. The efficacy and side effects of the same measures or drugs vary greatly among different individuals, and regular blood lipid levels, liver and kidney functions, muscle enzymes, and blood routine should be performed. With active comprehensive treatment, the prognosis of this disease is good.
Prevention
Popularize health education, advocate balanced diet, increase physical activity and sports, prevent obesity, avoid bad habits, and combine with the mission of prevention and treatment of chronic diseases such as obesity, diabetes, cardiovascular diseases, etc., in order to reduce the incidence of dyslipidemia.