What is Cholesterol?

What are LDL and HDL?

Cholesterol must be transported via the bloodstream by lipoproteins. The two main lipoproteins are LDL (low density lipoprotein), which is considered the "bad" cholesterol because it causes plaque buildup in the arteries, which can lead to heart disease. HDL is the other main lipoprotein and it is considered the "good" cholesterol because it collects the LDL/plaque from the arteries and transports them to the liver, where they are passed from the body.

How do LDL and HDL Differ?

HDL and LDL differ both structurally and functionally. Structurally, LDL is composed of around 25% protein and 50% lipid (hence the name: lipoprotein). Since protein is more dense than lipid, LDL stands for low-density lipoprotein since it has less protien. HDL consists of around 20% lipid and 50% protein, so it is named high-density lipoprotien.


Functionally, LDL is used to transport cholesterol throughout the body, but it may leave some in the arteries, causing plaque buildup. HDL is used to collect the LDL/plaque buildup in the arteries and transport it to the liver, where it is passed from the body.

What other molecules are monitored in the blood besides LDL and HDL?

There are two other components besides LDL and HDL that are measured in the blood and they are Triglycerides and VLDL.


Triglycerides are a type of fat responsible for energy supply for the muscles and energy storage. Even though there are very small amounts of triglycerides in the blood, too many of thm can increase the risk of heart disease.


VLDL is very-low-density lipoprotein, which contains very little protein. Their process is to transport triglycerides from the liver. High amounts of VLDL may also increase the risk of heart disease.

Why do doctors monitor LDL and HDL concentrations in the blood?

It is crucial that doctors monitor our LDL and HDL concentrations because they can determine health status and the risk of heart disease. If somebody is too low in HDL and/or too high in LDL, the may have high risk of heart disease. Also, if somebody has low amounts of LDL and/or high amounts of HDL, they may have little risk of heart disease.

How does one interpret their test results?

After recieving a blood test, a patient must know that high amounts of HDL are good and that means that they are fairly healthy and that they may have a loer risk of heart disease. Also, high amounts of LDL, Triglycerides, and VLDL can all mean that a patient is unhealthy and that they may have a high risk of heart disease.

How do patients change their test results?

First, a patient must take a blood test to know where they stand (less than 200 mg/dl of total cholesterol is healthy, less than 100 mg/dl of LDL is healthy, 40 or more mg/dl of HDL is healthy, and less than 150 mg/dl of Triglycerides is healhy). If any of these results are not where they should be, dietary and fitness changes should be made. By limiting cholesterol intake to 200-300mg per day, reducing the amount of calories consumed from fat, and incorporating at least 25 minutes of aerobic exercise 5 days a week, healthy levels of all components can be acheived and maintained.

How does the intake of saturated, unsaturated, and trans fat affect a patient's health?

Saturated fats and trans fats tend to raise blood cholesterol levels, while unsaturated fats tend to lower blod cholesterol levels.

References

Retrieved from http://healthyeating.com

Retrieved from http://livewell.com

Centers for Disease Control and Prevention. (n.d.). Retrieved from http://cdc.gov

www.heart.org. (n.d.). Retrieved from http://heart.org