How to use statins correctly?(Part 1: Blood lipids and related diseases.)✅✅✅

Statins are effective and safe in lowering cholesterol and reversing plaque. Clinically they have become fundamental drugs for reducing the risk of cardiovascular disease and treating atherosclerosis. Due to the widespread use of statins, incorrect use of statins can cause adverse reactions in patients.

What are blood lipids?

Cholesterol in the human body is mainly present in the body in the form of cholesterol esters and free cholesterol. Although lipids are insoluble in water, lipids in plasma are mainly combined with apolipoproteins to form soluble lipoproteins, so that plasma is normally clear and transparent. Lipoproteins are classified into high density lipoprotein (HDL), intermediate density lipoprotein (IDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL) and chylomicrons (CM). In addition, there is a lipoprotein called lipoprotein a (LPa). Lipoproteins are the major transport form of blood lipids in the human body. Clinically, the level of LDL in the blood can be reflected by the level of low-density lipoprotein cholesterol (LDL-C). In addition, there are triglycerides in the blood, which are also commonly known as fats. Clinically, the two main indicators of concern are LDL-C and cholesterol. Because only cholesterol is the basis pathophysiology of atherosclerosis.

What is atherosclerotic cardiovascular disease?

Atherosclerotic cardiovascular disease (ASCVD) includes ischemic stroke, myocardial infarction (MI), stable and unstable angina, transient ischemic attack, and peripheral vascular disease (PAD).

What is the source of cholesterol in blood?

The main sources of cholesterol in the blood are synthesis in the body and dietary intake. The amount of synthesized in the body is about 2/3 (70%-80%) and the amount of dietary intake is about 1/3 (20%-30%). The main site of cholesterol synthesis in the body is the liver. However, cholesterol cannot enter the blood directly after being synthesized in the liver. It is excreted into the intestines through bile, and then absorbed by the intestines into the blood. This process is called enterohepatic circulation of cholesterol. Both the cholesterol synthesized by the liver and the cholesterol absorbed from the diet must be absorbed by the intestine before entering the blood. Therefore, the ability of the intestines to absorb cholesterol greatly affects the level of cholesterol in the body's blood. Clinically, ezetimibe has a lipid-lowering effect by inhibiting the absorption of cholesterol in the intestines. 

What are the causes of hyperlipidemia?

The causes of hyperlipidemia include the following:

1. Diet can cause hyperlipidemia. Long-term consumption of high-sugar, high-fat and high-energy foods or beverages can easily lead to hyperlipidemia. Lack of physical activity or excessive alcohol consumption can lead to dyslipidemia.
2. The disease causes hyperlipidemia. Some diseases may cause dyslipidemia, such as: thyroid disease, liver disease, pancreatitis, diabetes, obesity, gout, familial hypercholesterolemia, etc. Hypothyroidism can cause hyperlipidemia including cholesterol and triglyceridemia.
3. Drugs can also cause hyperlipidemia. Some drugs can also increase blood lipids, such as glucocorticoids, non-selective β-blockers, and diuretics, which can induce secondary dyslipidemia.

Who needs to be screened for blood lipids?

The following people need to be screened for blood lipids:

Men or women over the age of 40 (or postmenopausal women).

All patients with any of the following conditions, regardless of age, should be screened for lipids.

• Clinical evidence points to the presence of atherosclerotic cardiovascular disease.
• Diabetes.
• Hypertension.
• Hypertension in pregnancy.
• Chronic kidney disease (eGFR≤60ml/min 1.73m2).
• Abdominal aortic aneurysm.
• Chronic Obstructive Pulmonary Disease.
• Signs of dyslipidemia (eg, xanthomas, corneal arches).
• Inflammatory diseases (inflammatory bowel disease, psoriatic arthritis, systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis). 
• Family history of premature cardiovascular disease (age of onset in first-degree relatives: female < 65 years, male < 55 years).
• Obesity (BMI ≥ 30). 
• Still smoking. 

How long is the interval between blood lipid tests?

People between the ages of 20 and 40 should have their blood lipids tested every 5 years.

Men over the age of 40 should have their blood lipids checked once a year.

Postmenopausal women should have their blood lipids checked once a year.

Patients with ASCVD or their high-risk groups should have blood lipids measured every 3 to 6 months. (High-risk groups refer to people with multiple ASCVD risk factors, such as diabetes, hypertension, familial hyperlipidemia, family history of premature cardiovascular disease, obesity, smoking, etc.)

Inpatients with ASCVD should be tested for blood lipids at the time of hospital admission.