What is Cholesterol?
Harris Meyers
HDL
HDL, short for High-Density Lipoprotein, is considered "good" cholesterol, again, there is no good or bad cholesterol. HDL removes extra cholesterol that is not necessary from the bloodstream. The cholesterol that is removed from the bloodstream from the HDL is then moved to the liver. If there is too much cholesterol, there can be a buildup of cholesterol in the arteries if HDL does not remove it. This is why there must be a balance of HDL and LDL. This balance aims to help keep circulating lipids from getting trapped in the arteries.
LDL
LDL, short for Low-Density Lipoprotein. It is a combination of lipids and proteins. LDL transports cholesterol to the cells. It is sometimes called "bad"cholesterol, high LDL levels lead to buildup in the arteries. But it is not good, nor is it bad! But is tends to strike a balance with HDL.
How do HDL and LDL Differ Structurally and Functionally?
Lipoproteins all have lipids and proteins in their structure, but they all have something difference between. The main difference between LDL and HDL is their composition. 50% of the weight of LDL is cholesterol while 25% of it is protein. HDL has 20% cholesterol and it has 50% protein. LDL is less dense than HDL, hence high density and low density. LDL carries different proteins types. LDL contains B-100 proteins. However, HDL contains A-I and A-II proteins. The importance of the proteins is that the function of the lipoprotein is determined by the type of protein that the lipoprotein carries.
Why Does a Doctor Monitor Concentrations of LDL and HDL in a Patients Blood?
HDL and LDL are monitored during a blood test because both of them are used to help monitor a patients risk for heart disease. During a blood test we can determine whether cholesterol is being taken out more or not taken out fast enough. HDL levels should be at the least 40mg/dL and at the most to 60mg/dL. LDL should be lower than 129mg/dL and it should be lower form anyone diagnosed with heart disease.
How are the Concentrations of LDL and HDL Associated with the Risk for Heart Disease and Associated Disorders?
Too much LDL results in plaque buildup on the walls of the arteries. This buildup can lead to atherosclerosis. Atherosclerosis is the hardening of arteries. Atherosclerosis leads to heart disease and then to heart attacks or strokes. High HDL levels lead to a lower risk of heart disease.
What Other Molecules in a Patient's Blood are Monitored Along with LDL and HDL?
Along with LDL and HDL levels for heart disease, we must also monitor plaque buildup, how stiff the artery walls are in general, and where the flow of blood is inhibited. Monitor how the body responds to a bad diet, lack of exercise, and being overweight and smoking. We also monitor triglycerides, total blood sugar levels, and total cholesterol levels.
What do the Results of a Cholesterol Test Mean? How Does a Patient Interpret Each Value?
When we see the results of a cholesterol test we usually see LDL, HDL and Triglyceride levels in the results. We also see a total blood cholesterol level included which is where many of the patients usually focus attention on. Here is how we measure each level and how it can be interpreted by the patient.
What can Patients do to Change the Levels of LDL and HDL in their blood? How does Intake of Different Fats Affect Cholesterol Levels and Overall Health?
A healthy diet and reduced fat/cholesterol level foods should be consumed. Saturated fat consumed should be less than 7% of the total calories the patient intakes everyday. It is recommended that you stay active, participating in at least 30 minutes of physical activity at least 5 days a weak. If you can do more, go for it because that could also help.
Sources:
http://www.nhlbi.nih.gov/health/health-topics/topics/hbc
http://healthyeating.sfgate.com/ldl-hdl-differ-structurally-functionally-2003.html
http://www.mayoclinic.org/diseases-conditions/heart-disease/basics/causes/con-20034056
http://www.webmd.com/cholesterol-management/cholesterol-tests-understand-your-results?page=2