Discuss some characteristics, measurement, and forms of cholesterol and their relationship to cardiovascular disease (CVD).​

A. Cholesterol is a fat-like, waxy substance produced by the liver. As a part of the cell membranes, it is essential for human life. However, too much can contribute to CVD.
B. Dietary cholesterol comes from animal food products.
C. Serum cholesterol is the level of cholesterol circulating in the bloodstream.
D. Dietary and serum cholesterol are related, but not perfectly.
E. Serum cholesterol is measured as milligrams (mg) per deciliter (dl) of blood serum.
1. A total cholesterol measure of 200 = 200 mg cholesterol per deciliter of blood serum.
F. CVD is not best predicted by total serum cholesterol.
G. Several forms of lipoproteins make up serum cholesterol.
1. Low-density lipoprotein (LDL) transports cholesterol from the liver to body cells.
2. High-density lipoprotein (HDL) transports cholesterol from the tissues to the liver.
3. HDL is found somewhat protective against CVD.
4. LDL is believed to promote atherosclerosis.
5. HDL is sometimes called "good cholesterol" and LDL "bad cholesterol."
6. Very low-density lipoprotein (VLDL) is another name for triglycerides.
7. Total cholesterol is calculated by adding HDL, LDL, plus 20% of VLDL.
H. A ratio of <4.5:1, i.e. HDL that is c. 20-22% of total cholesterol, lowers CVD risk.
I. A ratio of 6:1 in HDL to total cholesterol is associated with higher risk of CVD.
J. The focus of much research recently has been changing the diet and/or using drugs to lower LDL.
K. Conclusions suggested by cholesterol research:
1. Blood cholesterol and dietary cholesterol are related.
2. Long-term dietary habits are strongly related to the relationship of dietary and blood cholesterol.
a. Dietary change can lower serum cholesterol, but this is typically a slow and difficult process.
3. It is important to lower LDL; however, most experts now agree that the ratio of HDL to total cholesterol is more critical in avoiding CVD than total cholesterol alone is.