Statin Science

Cholesterol is a fatty substance (lipid). It forms part of a group of biological substances called sterols, which are solid alcohols that, like all alcohols, can form esters with fatty acids. In plasma (a component of blood), most of the cholesterol is esterified, whereas in cells it is free. High cholesterol is also known by the medical term "hyperlipidemia".

Statins work by inhibiting the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, which is a major enzyme involved in synthesising cholesterol in the liver. This results in reduced cholesterol levels in liver cells, which then meet their cholesterol requirements by taking up cholesterol circulating in the blood, via a protein on the liver cell surface called an LDL receptor. LDL receptors break down the circulating cholesterol, which results in reduced levels of LDL cholesterol in the blood. Evidence exists to suggest that statins increase the number of liver cell LDL receptors.

Between 1978 and 1995, average total cholesterol levels among U.S. adults fell from 213 mg/dL to 203 mg/dL, and the prevalence of cholesterol of 240 mg/dL or higher declined from 26 percent to 19 percent. Moreover, congestive heart disease mortality continued to decline.

More on niacin for cholesterol control.

It is wrong to assume that drugs work solely because of their interaction with a specific receptor in the body. While that is important, other factors are also critical, including how fast the drug is absorbed into the tissue (called “uptake”), distribution of the medicine through the body (which can have both positive and negative effects), degradation or metabolism of the drug before it gets to the target receptors, rate of metabolism of the drug and its breakdown products, and how fast the drug is eliminated (either by removal through the kidneys or breakdown in the liver.)

Hypercholesterinaemia (or just Hyperlipidemia) is a fancy medical name for high cholesterol in the blood. It is one of the major risk factors for arteriosclerosis. Doctors prescribe statins to control hypercholesterinaemia.

Less than half the cholesterol in the bloodstream comes from diet. Most is made by the body – in particular by the liver. It is inside the liver cells that the statin drugs work. Chemotherapy medicines bind with the cell’s DNA to inhibit cell division and tumor growth. Antibiotics react with enzymes to prevent synthesis of components of the cell wall – this is how they stop the multiplication of bacteria. Statins inhibit an enzyme critical for cholesterol synthesis inside liver cells. Of course, there is plenty of inactive material inside a statin pill.

The Difference Between LDL and HDL

High-density lipoproteins (HDL) - sometimes called "good" cholesterol - reduce cholesterol's effects on blood vessels by carrying the cholesterol to the liver. It's a complex of protein and cholesterol. (Cholesterol is a lipid and a type of compound called a steroid.) The general benchmark for the target HDL is 40 mg/dl. You want your level to be higher than this.

Low-density lipoproteins (LDL) - the bad cholesterol - is the stuff that builds up plaque on your blood vessels.

In the bloodstream, lipids are transported in a protein coat. The density of the cholesterol inside the protein capsule affects whether the cholesterol contributes to plaque on the blood vessels and its influence on metabolism.