high density lipoprotein cholesterol:
Does reducing blood lipids mean controlling triglycerides?
It has been firmly established that increased cholesterol levels increase the risk of coronary heart disease. A 10% reduction in total cholesterol corresponds to a 15% decrease in the risk of death from coronary heart disease and an 11% overall reduction in the risk of death. Low-density lipoprotein cholesterol (LDL-C) is related to atherosclerosis and coronary heart disease risk, and its reduction by 10% leads to a 20% decrease in coronary heart disease risk. Therefore, LDL-C is the primary target for preventing and treating coronary heart disease, and the most important aspect of lipid-lowering is to reduce LDL-C, rather than triglycerides.
Additionally, diabetes, as a high-risk condition for coronary heart disease, has a greater than 20% risk of myocardial infarction in the next 10 years, which is equivalent to the risk of a myocardial infarction in someone who has already had one. Although lipid abnormalities in diabetes are often characterized by high triglycerides and low high-density lipoprotein cholesterol (HDL-C), LDL-C is more important. As long as the LDL-C level does not reach the target (2.6 mmol/L < 100 mg/dL), reducing LDL-C remains the primary intervention goal.
Do oral contraceptives affect blood lipids?
Long-term use of contraceptives can cause some adverse reactions, such as affecting blood lipids. Oral contraceptives are artificial syntheses made of different types of estrogens and progestins in different ratios. In recent years, extensive research has concluded that oral contraceptives can increase cholesterol, triglycerides, LDL-C, and VLDL-C levels in the blood, which increases the risk of atherosclerosis and increases the risk of coronary atherosclerotic diseases.
A follow-up study conducted in the United States on 2606 white women found that compared to those who did not use oral contraceptives, those who did had significantly increased levels of low-density lipoprotein cholesterol and triglycerides in their blood. The ratio of estrogens to progestins in these drugs is an important factor that affects the level of low-density lipoprotein cholesterol. The higher the estrogen content, the more significant the increase in low-density lipoprotein cholesterol, while progesterone has the opposite effect. Therefore, the use of contraceptives should not be random, but rather selective. Experimental research has shown that formulas containing low doses of estrogen and Methylnorethindrone have no effect on blood lipids and are effective.
Why does “normal” blood lipids still cause tragedy?
At 41 years old, Jack asked his doctor if his blood lipids were normal with the test results. The doctor replied that they were within the normal range. Shortly afterwards, Jack suddenly suffered a myocardial infarction during a trip and died without timely rescue. The autopsy revealed that the left coronary artery was 100% blocked, but the arteriosclerotic plaque in this area only blocked 25% of the blood vessel lumen. The remaining 75% was occupied by fresh thrombi.
The direct cause is that the blood flow impinges on the atherosclerotic plaque here, resulting in sudden rupture, and a large number of platelets gather and block at the rupture and bleeding place. The blood flow is interrupted due to the blockage of blood vessels, which eventually leads to cardiac arrest and sudden death due to myocardial ischemia and hypoxia.
Why is there such a tragedy when blood lipids are in the “normal” range? Experts analyzed his blood lipid indicators: total cholesterol 2.5 mmol / L (97 mg / dl), triacylglycerol 1.55 mmol / L (141 mg / dl), low-density lipoprotein cholesterol 3.59 mmol / L (138 mg / dl), high-density lipoprotein cholesterol 0.9 mmol / L (35 mg / dl), all on the edge of normal, just “passed”. This is like the 100 point test system, he only got 60 points!
Medical research has confirmed that lecithin in blood lipids and high-density lipoprotein work together to clean blood, clean and dredge blood vessels. The higher the normal range, the better. The essence of hyperlipidemia is that low lecithin leads to low high-density lipoprotein and high total cholesterol and triacylglycerol. Normal range of high density lipoprotein cholesterol: 0.9~2.2 ml (35~85 mg%). In high-density lipoprotein, lecithin accounts for 32%, cholesterol accounts for 17%, and lecithin: cholesterol =2:1. Lecithin is a “transport ship”, cholesterol is a “cargo”.
The characteristics of high-density lipoprotein: lecithin content is high, cholesterol is low, and the ship is large and cargo is small. It is a “blood cleaning ship”. It has spare power to “load” the cholesterol in the blood and blood wall to the liver for metabolism, so as to prevent the deposition of lipids on the blood vessel wall from the root. High density lipoprotein cholesterol increased by 0.03 mmol / L (1 mg%), and the risk of cardiovascular and cerebrovascular disease decreased by 4%.
“Good cholesterol” is the cholesterol in high-density lipoprotein. In LDL, lecithin accounts for 22% and cholesterol accounts for 45%. Lecithin: cholesterol = 1:2, which is an “overloaded sunken ship”. Loaded with a large amount of cholesterol, it is very easy to “capsize and sunken” and deposit on the vessel wall to form easily ruptured patches. “Bad cholesterol” refers to the cholesterol in LDL, and its normal range is 1.8~3.6 mmol / L (70~140 mg%), which is better below 2.6 mmol / L (100 mg%). Zhang’s high-density lipoprotein cholesterol is very low, and his blood cleaning ability is very poor. Fragile plaques have formed in the coronary arteries, and sudden myocardial infarction is inevitable.
