Why are so many people prescribed statins?

As well as obtaining cholesterol from food we also constantly manufacture it in the liver.  Most people should be able to reduce their blood cholesterol to healthy levels (160mg/dL or less) by reducing their intake of fat and cholesterol-rich foods. 

But some people have an inherited metabolic fault which causes them to have high levels of cholesterol in the blood.  Modifying diet alone may not lower cholesterol levels enough in these people or in those with type 2 diabetes, which is also a metabolic disease. Statins work by blocking the process of cholesterol production in the liver.

What is so bad about high cholesterol?

Cholesterol is an essential constituent of many parts of our bodies, including the membranes surrounding each cell, the crystalline lens in our eye, and hormones such as estrogen and testosterone.  But an excessive level of cholesterol in the blood is associated with blockage of arteries – such as those supplying the brain, heart and legs.  In these diseases, cholesterol forms solid slabs (‘plaques’) on the internal walls of our blood vessels – in those supplying the heart muscle in the case of coronary heart disease. 

The plaques lead to progressive narrowing of the blood vessels until blood can no longer pass through it.  The muscle or tissue dependent on that blood supply will be damaged, and if the supply is not quickly restored, will die. This is what happens in a heart attack or stroke – part of the heart muscle or brain is starved of blood and oxygen and may be left permanently damaged.

So should everyone take a statin?

These are all aimed at reducing the risk of coronary heart disease which is predicted to become the world’s leading cause of death and disability by 2020. But this would mean exposing people to the side effects of drugs like statins, when their risk of heart disease may be very small.

Dr Golomb commented that people without risk factors for coronary heart disease are more likely to experience a side effect from taking a statin than they are to have a coronary event.

Who should be taking a statin?

There is clear evidence that people with multiple risk factors for heart disease (including type 2 diabetes) or who already have heart disease, could benefit substantially from taking a statin as part of treatment to modify their risk.

In such cases it is likely that the potential benefits will outweigh the risks of side effects. Not everyone experiences the side effects mentioned and it may be possible to modify them by changing the statin, or its dose or combining it with a different class of lipid (fat) lowering drug.