Question

Chapter 26 1) Considering serum lipoprotein composition and lipoprotein processing, explain why it matters if a patients' “high cholesterol" is mostly VLDL? How can you treat this condition?

Answer 1

Low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL) are two different types of lipoproteins found in your blood. Lipoproteins are a combination of proteins and various types of fats. They carry cholesterol and triglycerides through your bloodstream.

Cholesterol is a fatty substance that’s necessary for building cells. In the body, it’s most commonly created in your liver through a complex pathway. Triglycerides are another type of fat that’s used to store extra energy in your cells.

The main difference between VLDL and LDL is that they have different percentages of the cholesterol, protein, and triglycerides that make up each lipoprotein. VLDL contains more triglycerides. LDL contains more cholesterol.

VLDL and LDL are both considered types of “bad” cholesterol. While your body needs both cholesterol and triglycerides to function, having too much of them can cause them to build up in your arteries. This can increase your risk for heart disease and stroke.

VLDL is created in your liver to carry triglycerides throughout your body. It’s made up of the following componentsTrusted Source by weight:

Main components of VLDL	Percentage
cholesterol	10%
triglycerides	70%
proteins	10%
other fats	10%

The triglycerides carried by VLDL are used by cells in the body for energy. Eating more carbohydrates, or sugars, than you burn can lead to excessive amounts of triglycerides and high levels of VLDL in your blood. Extra triglycerides are stored in fat cells and released at a later time when needed for energy.

High levels of triglycerides are linked to the buildup of hard deposits in your arteries. These deposits are called plaques. Plaque buildup increases your risk for heart disease and stroke. Experts believe this is due to:

• increased inflammation
• increased blood pressure
• changes in the lining of blood vessels
• low levels of high-density lipoprotein (HDL), the “good” cholesterol

High triglycerides are also associated with metabolic syndrome and nonalcoholic fatty liver disease.

Since VLDL and triglycerides are linked,can lower VLDL level by lowering your triglyceride level. May be able to lower your triglycerides with a combination of losing weight, diet, and exercise. It is important to switch to healthy fats, and cut back on sugar and alcohol. Some people may also need to take medicines.

The choice of medication or combination of medications depends on various factors, including your personal risk factors, your age, your health and possible drug side effects. Common choices include:

Statins. Statins block a substance your liver needs to make cholesterol. This causes your liver to remove cholesterol from your blood.

Choices include atorvastatin (Lipitor), fluvastatin (Lescol XL), lovastatin (Altoprev), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor) and simvastatin (Zocor).

Bile-acid-binding resins.

Cholesterol absorption inhibitors.

Injectable medications. A newer class of drugs, known as PCSK9 inhibitors, can help the liver absorb more LDL cholesterol — which lowers the amount of cholesterol circulating in your blood. Alirocumab (Praluent) and evolocumab (Repatha) might be used for people who have a genetic condition that causes very high levels of LDL or in people with a history of coronary disease who have intolerance to statins or other cholesterol medications.

• Fibrates. The medications fenofibrate (TriCor, Fenoglide, others) and gemfibrozil (Lopid) reduce your liver's production of very-low-density lipoprotein (VLDL) cholesterol and speed the removal of triglycerides from your blood. VLDL cholesterol contains mostly triglycerides.

  Using fibrates with a stain can increase the risk of statin side effects.

• Niacin. Niacin limits your liver's ability to produce LDL and VLDL cholesterol. But niacin doesn't provide additional benefits over statins. Niacin has also been linked to liver damage and strokes, so most doctors now recommend it only for people who can't take statins.

• Omega-3 fatty acid supplements. Omega-3 fatty acid supplements can help lower your triglycerides. They are available by prescription or over-the-counter.

  If you choose to take over-the-counter supplements, get your doctor's OK. Omega-3 fatty acid supplements could affect other medications you're taking.