膽固醇數字:它們是什麼意思?

What is cholesterol?

You may have heard of cholesterol, but you may not be sure what it is. Cholesterol is a waxy fat or lipid that moves in the blood throughout the body. Lipids are water-insoluble substances, so they will not be broken down in the blood. Your body makes cholesterol, but you can also get it from food. Cholesterol is only found in food from animals.

Why is cholesterol important to our body?

Every cell in the body needs cholesterol, which helps the formation of cell membranes. These layers protect the contents of the cell by acting as gatekeepers where things can enter or leave the cell. It is made by the liver and is also used by the liver to make bile to help you digest food. Cholesterol is also needed to make certain hormones and vitamin D. Your liver will produce enough cholesterol to meet your body's needs for these important functions.

What are the types of cholesterol?

Cholesterol is carried throughout the body by lipoproteins in the blood. These lipoproteins include:

  • Low-density lipoprotein (LDL) is one of the two main lipoproteins. Low-density lipoprotein is often referred to as "bad cholesterol."
  • High-density lipoprotein (HDL) is another major lipoprotein. HDL is often referred to as "good cholesterol".
  • Very low-density lipoproteins (VLDL) are particles that carry triglycerides in the blood.

If cholesterol is necessary, why should we worry about how much we have?

It is important to have enough cholesterol to meet your needs. High cholesterol can cause problems. If your cholesterol level is high, this condition is called hypercholesterolemia . If your cholesterol level is low, this condition is called hypocholesterolemia. Low cholesterol levels are not common , but they can happen.

What is low-density lipoprotein (LDL)?

When we always hear about how we should lower cholesterol, you might think that it is strange that LDL is called bad cholesterol. However, LDL is "bad" because of its effect.

Low-density lipoproteins can accumulate on the walls of your arteries, making them narrow. Fat deposits form plaques that line your arteries and can cause blockages. This accumulation is called atherosclerosis.

Arteries are blood vessels that carry oxygen-rich blood from the heart to all other organs in the body.

Fats related to low-density lipoprotein cholesterol levels and fats that should be minimized in the diet are called saturated fats and trans fats. Saturated fats are solid or waxy at room temperature. You will usually find saturated fats in products derived from animals, such as meat, milk, cheese, and butter.

When liquid fat becomes solid through the hydrogenation process, trans fat is produced. Trans fats are found in fast food and fried foods and are used to extend the shelf life of processed foods such as biscuits, crackers and bakeries.

What is high-density lipoprotein (HDL)?

High-density lipoprotein is called "good cholesterol". This is good because it can take away other types of cholesterol (including low-density lipoprotein) from the arteries. It might help to think of HDL as a delivery truck and LDL as a dump truck. HDL removes other types of cholesterol in the liver for removal from the body. It is believed that higher levels of HDL can reduce the risk of heart disease.

What kind of test measures cholesterol?

Everyone over the age of 20 should have their cholesterol level measured at least once every five years. Your healthcare provider will request a blood test to show how much cholesterol your blood contains. This test will provide your cholesterol level. Your provider may also order the so-called lipid panel or lipid mass spectrometry. This panel provides you with the following numbers:

  • Total cholesterol.
  • Low-density lipoprotein levels.
  • High-density lipoprotein levels.
  • VLDL levels and triglycerides.
  • Non-high-density lipoprotein cholesterol.
  • The ratio between cholesterol and high-density lipoprotein.

There are some advanced tests that can break down the size and shape of LDL cholesterol levels and give the number of LDL particles, but these are usually not ordered. Some test manufacturers say that more advanced tests can better show who is at risk for heart disease, but most providers still believe that the usual tests are sufficient.

How to perform a total cholesterol or blood cholesterol test?

The blood test is a routine test. The job of a blood draw doctor is to draw blood. The blood is usually drawn from a vein in your arm. You will sit down and the blood tester will wrap a rubber band around your upper arm so that the veins in your elbow will stick out. Then they will puncture the vein with a needle and remove the blood. The blood is sent to the laboratory for examination.

You may have been to a health fair that offers testing. In this case, the person performing the test will take a drop of blood from your finger. The finger stick test uses a small blade to poke a hole in the fingertip to get blood.

How do you prepare for the cholesterol test?

In most cases, you will need to fast for 9 to 12 hours before the test. Make sure you tell the person taking the blood how long it has been since you have eaten or drunk anything other than water.

In some cases, the cholesterol test is performed without fasting. This applies to tests performed during a health check, and may apply to people under 20 years of age or people who cannot fast.

Some medical associations believe that fasting is not necessary to obtain the true level of lipids in the blood, while other associations believe that fasting can better understand a person’s heart disease risk. Before the blood test, you should know whether you need to fast and how long.

How long does it take to get results from the cholesterol test?

Your results will usually be available within a day or two. In the case of screening and fingertip tests, you will get results immediately. In either case, you will need to talk to your healthcare provider to discuss the results. The result is usually expressed in milligrams per deciliter (mg/dL).

Is the home cholesterol test kit accurate?

If the test is marked as "CDC Certified", the answer is yes. This means that the content has been approved by the Cholesterol Reference Method Laboratory Network, which works with test manufacturers, laboratories, and the Centers for Disease Control and Prevention (CDC) to ensure that the tests are accurate.

For home testing, you still need to fast for 12 hours and collect blood for testing. Some kits come with packages for mailing to the laboratory for results. Other kits have a monitor, so you can get results at home. The cost of this type of home kit varies.

What is the normal level of cholesterol?

The normal level of cholesterol varies depending on your age and gender. These guidelines show ideal total, non-HDL, LDL, and HDL levels by age and gender.

Table 1: Target cholesterol levels by age and gender

Age and gender

All

cholesterol

Non-high density lipoprotein

cholesterol

Low-density lipoprotein

cholesterol

High density lipoprotein

cholesterol

People 19 years
and younger
Less than 170 mg/dLLess than 120 mg/dLLess than 110 mg/dLMore than 45 mg/dL
Men 20 years
and older
125 mg/dL to 200 mg/dLLess than 130 mg/dLLess than 100 mg/dL40 mg/dL or higher
Women 20 years
and older
125 mg/dL to 200 mg/dLLess than 130 mg/dLLess than 100 mg/dL50 mg/dL or higher

The above table lists the numbers for normal cholesterol levels. The table below shows cholesterol levels that are higher than normal. High cholesterol levels vary by age group and gender, and people with heart disease may vary. These guidelines represent the high cholesterol values ​​of those who do not have heart disease.

Table 2: High total cholesterol, non-HDL and LDL cholesterol levels by age and gender

Age and genderTotal cholesterolNon-high density lipoprotein cholesterolLow Density Lipoprotein Cholesterol
People 19 years and younger (children and adolescents)

Cut-off value: 170-199 mg/dL

High: greater than or equal to 200 mg/dL

Cut-off value: 120-144 mg/dL

High: greater than or equal to 145 mg/dL

Cut-off value: 110-129 mg/dL

High: greater than or equal to 130 mg/dL

Men 20 years
and older

Threshold: 200-239 mg/dL

High: greater than or equal to 239 mg/dL

High: more than 130 mg/dL

Close to optimal or higher than optimal: 100-129 mg/dL

High critical value: 130-159 mg/dL

High: 160-189 mg/dL

Very high: greater than 189 mg/dL

Women 20 years
and older

Threshold: 200-239 mg/dL

High: greater than or equal to 239 mg/dL

High: more than 130 mg/dL

Close to optimal or higher than optimal: 100-129 mg/dL

High critical value: 130-159 mg/dL

High: 160-189 mg/dL

Very high: greater than 189 mg/dL

Low-density lipoprotein cholesterol level

If you do not have heart disease or vascular disease, and you are not at high risk of heart disease, the best (or best) number is less than 100 mg/dL.

If you do have heart or vascular disease, or have multiple risk factors, your healthcare provider may want your LDL level to be less than 70 mg/dL. If you have diabetes, your healthcare provider will want your LDL level to be less than 100 mg/dL, or even less than 70 mg/dL.

Triglycerides

Triglycerides are important because most of the fat in your body is in the form of triglycerides. These levels are usually higher in people with diabetes or obesity. For triglycerides, the details you want to know about the numbers are:

  • If they are less than 150, it is normal.
  • If they are 150-199, they are critically high.
  • If they are 200-499, it is high.
  • If they are 500 or higher, they are very high.

HDL cholesterol levels

The higher number you want is the HDL number (remember, it is good cholesterol).

  • HDL below 40 is considered poor and is a risk factor for heart disease in men and women.
  • The HDL goal for men is 40 or higher, and achieving this goal is considered good.
  • Women’s HDL goal is 50 or higher, and achieving this goal is considered good.
  • An HDL of 60 or higher is considered the best and can prevent heart disease.

Is the "bad" cholesterol level too low? Is the "good" cholesterol level too high?

People usually don't have too low bad cholesterol or too high good cholesterol. Ongoing research shows that any type of extreme situation is not healthy for everyone.

Although there is no clear figure for LDL levels that are too low, levels below 40 mg/dL may be related to certain health problems, including depression/anxiety and hemorrhagic stroke.

However, data from clinical trials support that when LDL remains <40mg/dl during statin treatment, there is no evidence that it is harmful.

In some cases, genetic conditions can cause your cholesterol levels to be very low. In other cases, nutritional problems, certain cancers, hypothyroidism, and certain infections can also cause low cholesterol levels. In any of these types of situations, potential problems need to be addressed.

In terms of eating too many good things, researchers are studying the effects of too much HDL (good cholesterol). No conclusions have been drawn, but the possible relationship between high HDL and cancer has been studied, and high-risk people have a higher risk of heart attack. An HDL that is too high may be a dysfunctional HDL and has no protective effect.

What factors affect cholesterol levels?

Many factors can affect your cholesterol levels. They include:

  • Diet: Saturated fat, trans fat, and cholesterol in the food you eat will increase cholesterol levels. Try to reduce the amount of saturated fat, trans fat, and cholesterol in your diet. This will help lower your blood cholesterol levels. Saturated fats and trans fats have the greatest impact on blood cholesterol.
  • Weight: In addition to being a risk factor for heart disease, being overweight also increases your triglycerides. Losing weight may help lower triglyceride levels and increase HDL.
  • Exercise: Regular exercise can lower total cholesterol levels. Exercise has the greatest effect on lowering triglycerides and increasing high-density lipoprotein. You should try 30 minutes of physical activity for most of the week.
  • Age and gender: As we age, cholesterol levels will rise. Before menopause, women's total cholesterol levels are often lower than men of the same age. However, after menopause, women's low-density lipoprotein levels will increase, while high-density lipoproteins will decrease.
  • Heredity: Your genetic part determines how much cholesterol your body produces. High blood cholesterol can be inherited in the family.

What should you know about cholesterol and heart disease?

Preventing and treating heart disease is the main reason why your healthcare provider looks at cholesterol levels. Heart disease is a general term that may apply to many situations, but in this case, we are talking about coronary artery disease (CAD).

How is high cholesterol treated?

There are several ways to lower high blood cholesterol (total cholesterol), including lifestyle changes or medications, or both. Your healthcare provider will work with you to determine which treatment (or combination of treatments) is best for you.

Lifestyle changes

Healthcare providers like to start with the least invasive treatment possible, such as lifestyle changes. Will recommend you:

  • Avoid tobacco. If you smoke, please quit smoking. Smoking is bad for you in many ways, and lowering good cholesterol levels is one of them.
  • Change the way you eat . Limit the content of trans fat and saturated fat. Eat heart-healthy foods such as fruits, vegetables, poultry, fish, and whole grains. Restrict red meat, sugary products and dairy products made with whole milk.
  • exercise more. Try to do about 150 minutes of physical exercise every week, or about 30 minutes of physical exercise every day for most of the week.
  • Maintain a healthy weight. If you need to lose weight, discuss safe methods with your healthcare provider. You will see results even before you reach your ideal weight. Even if you lose 10% of your body weight, your cholesterol levels will vary.
  • Reduce the impact of negative emotions. Learn healthy ways to deal with anger, stress or other negative emotions.
  • Control blood sugar and blood pressure. Make sure you follow the blood sugar level instructions of your healthcare provider, especially if you have diabetes and keep your blood pressure within a healthy range.

drug

There are several different types of drugs designed to treat high cholesterol levels.

Statins are one of the most famous classes of cholesterol drugs. Statins work by reducing the amount of cholesterol produced by the liver. Statins can lower blood cholesterol and may help reduce the risk of heart attack and stroke, which is one of the reasons why they are widely used. The statins available in the United States include:

  • Atorvastatin (Lipitor®).
  • Fluvastatin (Lescol®, Lescol XL®).
  • Lovastatin (Mevacor®, Altoprev®).
  • Pravastatin (Pravachol®).
  • Rosuvastatin (Crestor®).
  • Simvastatin (Zocor®).
  • Pitavastatin (Livalo®, Zypitamag®).

There are also combinations of statins, such as Advicor® (lovastatin and niacin), Caduet® (atorvastatin and amlodipine), and Vytorin® (simvastatin and ezetimibe).

Statins are not suitable for all people with high cholesterol, especially those with liver problems. Although side effects are not common, they may include muscle pain, elevated blood sugar levels, and memory problems.

Bile acid sequestrants or bile acid binding drugs are another class of drugs that treat high cholesterol levels. These drugs, also called resins, attach to bile acids and then cannot be used for digestion. In response, the liver makes more bile by consuming more cholesterol. These drugs include:

  • Cholestyramine (Questran®, Questran® Light).
  • Colestipol (Colestid®)。
  • ColesevelamHcl (WelChol®)。

Resin is not for everyone. These drugs also have side effects such as constipation and stomach pain.

Fibrates are also called fibric acid derivatives. They are more effective in lowering triglyceride levels than LDL cholesterol. They may also help increase high-density lipoprotein cholesterol levels. These products include:

  • Fenofibrate (Antara®, Tricor®, Fenoglide®, Fibricor®, Lipidil®, Lipofen®, Trilipix® and Triglide®)
  • Gemfibrozil (Lopid®)

Other classes of drugs that health care providers may recommend to lower low-density lipoprotein cholesterol include:

  • PCSK9 inhibitors, including alirocumab and evolocumab.
  • Selective cholesterol absorption inhibitors, such as ezetimibe (Zetia®).
  • Adenosine triphosphate-citrate lyase (ACL) inhibitors, such as bempedoic acid (Nexletol®).
  • Omega 3 fatty acids and fatty acid esters.
  • Niacin, also known as niacin.

If you are taking statins and fail to lower your LDL to a level that your provider thinks is low enough, you may get a prescription for these drugs.

For people who do not get enough help from lifestyle changes and medications, usually those with genetic problems, there is a process called lipoprotein apheresis . This means using equipment to remove lipoproteins from blood and plasma, and then return the blood and plasma to the body. This process may be combined with some new drug treatments.

If you do not treat high cholesterol levels in the blood, what complications might occur?

The main reason for treating high cholesterol is to prevent or treat coronary heart disease (CHD), also known as coronary artery disease or CAD. CHD occurs when the heart cannot get enough oxygen-rich blood to function properly and more people are killed in the United States than any other cause of death. CHD usually refers to the large arteries, but there is also a disease called coronary microvascular disease, which affects small blood vessels and causes damage.

Can you get rid of cholesterol deposits?

Researchers are studying ways to eliminate plaque (cholesterol deposits) from the coronary arteries. One approach that has been proposed is the combined use of drugs (statins and PCSK9 inhibitors) in healthy people between 25 and 55 years of age. It is recommended that lowering the cholesterol level to a very low level will allow the arteries to clear and heal.

Several researchers believe that the way to reverse heart disease and prevent it in the first place is found in a whole plant-based diet. Studies that have been done have shown that limiting nutrients to plant-based whole foods has successfully reduced blood cholesterol and, in some cases, reduced plaque formation.

How to prevent high cholesterol levels and coronary heart disease (CHD)?

Prevention methods are very similar to treatment methods. First of all, don't smoke. If you smoke, make a plan to quit smoking immediately. Find a way to increase your physical activity every day. Take steps to keep your weight within a healthy range. Eat well. Consider following the Mediterranean diet. It is the only diet that has been proven to reduce the risk of heart disease. Follow the advice and instructions of your healthcare provider to take care of any other medical conditions you may have. Learn to really relax and calm down.

When should you contact your healthcare provider to find out about your cholesterol level?

In fact, your healthcare provider may discuss your numbers with you first. As always, if you have any new or worsening pain or other uncomfortable feelings, please contact your provider. Make sure you know the medicines you are taking and their effects. If you respond to medication, call the provider.

Before you go to the office and after you have a cholesterol test, it is helpful to prepare a list of questions about your test results and any recommended treatments.

Generalize

When considering cholesterol numbers, it is important to remember that you do have the ability to make these numbers work for you. What you choose to eat, how much you can move, and how you deal with the ups and downs in life are all things you can influence.

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