High Cholesterol

What is cholesterol?

Cholesterol and triglycerides make up the body 'lipids', the fatty substances in the body. Cholesterol does play an important part in the body and its cells, but too much can leads to furring up of the arteries and cardiovascular disease.

Cholesterol is mainly made in the liver from saturated fats in food, and in fact very little is found in foods.

There are two main types of cholesterol, LDL cholesterol and HDL Cholesterol. LDL cholesterol carries cholesterol from the liver around the body and to the arteries and is therefore 'bad' cholesterol. HDL cholesterol on the other hand returns cholesterol to the liver and so is 'good' cholesterol.


How does cholesterol affect coronary artery disease?

Cholesterol can be deposited within the walls of the arteries leading to narrowing of the arteries or plaques. This happens over many years and is even seen from an early age in children.

In the heart these plaques of cholesterol may restrict the flow of blood causing angina, or if the plaque splits a blood clot can form over the top suddenly blocking the artery and causing a heart attack.


What are normal levels of cholesterol?

The average cholesterol level in the UK is around 5.5mmol/l. Whilst lower than it used to be it is still too high and as a population we should aim to get it lower. It is important to remember that cholesterol is one of the major risk factors for coronary heart disease, along with diabetes, smoking, high blood pressure, physical inactivity, being overweight, having a family history of heart disease or being of South Asian origin (see Risk Assessment).


What are the targets for cholesterol levels?

The target depends on whether there is known cardiovascular disease (coronary heart disease, stokes, peripheral artery disease) or not.

If there are already signs of arterial disease then as part of 'secondary prevention' the cholesterol should be lowered to less than 4mmol/l and LDL targets for cholesterol less than 2mmol/l.There is no specific target for HDL targets for cholesterol but ideally this should be above 1mmol/l.

If there is no known arterial disease but a significant risk of it developing then as part of 'primary prevention' the cholesterol should be treated (see Risk Assessment). The NICE guidelines do not set specific targets on treatment.


How can I lower cholesterol?

Cholesterol can be lowered both by lifestyle changes and by medication. It is also important to treat the other risk factors such as blood pressure, smoking etc.

Lifestyle changes are mainly diet and exercise (and stopping smoking):

       Diet - a healthy diet can help reduce cholesterol levels by 10%. Both the total amount of fat in the diet and the amount of saturated fats should be reduced. Oily fish provide a good source of omega-3 fats that are particularly good for the heart. Specific types of food are detailed in many websites and the BHF 'Reducing your cholesterol' booklet is particularly good.
        Exercise - regular exercise increases the HDL (good) cholesterol as well as helping with blood pressure. We should all aim to exercise for 30 minutes a day for 5 days a week. The 30 minutes can be divided up each days, but you cannot carry over the exercise from one day to another!. With exercise the aim should be to feel warm and slightly breathless, but so breathless that you cannot talk.


Medication for reducing cholesterol - the 'statins'

Statins are the main types of drugs for reducing cholesterol. They are very effective at reducing cholesterol levels and can achieve lower levels than diet alone (though when taken to reduce cholesterol should be used in combination with a low fat diet).

There are several stains, the main examples being simvastatin, atorvastatin, rosuvastatin and pravastatin.

They reduce cholesterol levels and stabilise the plaques of cholesterol already present to reduce the chance of them forming clots and blockages.

Statins reduce the risk of heart attacks and strokes. All people who have had an arterial problem should be on a statin, even if the starting cholesterol is normal as the statin will still reduce the future risk.

Statins are not a substitute for a low fat diet and healthy lifestyle but shoudl be used in conjuction with these.


What are the possible side effects of statins?

Statins may cause nausea, diarrhoea and aching joints in a small number of cases. Serious side effects are very rare - the statins can cause muscle inflammation and any muscle aches should be reported to your doctor who will check  a blood test and consider changing the statins or reducing the dose.

The statins will only be started after assessment of the balance between benefit and risk in you. The British press often publish bad news about statins! It is important to remember that statins are a very effective therapy and have been part of many,\many clinical trials. They are proven to significantly reduce the risk of heart attacks and strokes.

What other medications are used?

Less commonly used medications are:

Fibrates - such as bezafibrate and fenofibrate. These are good at reducing the triglyceride levels in the blood, but not so effective at reducing cholesterol as the statins. They are sometimes used in conjunction with statins but only with carefulmonitoring.

Ezetimibe - this lowers cholesterol in a different way to statins. It is not very effective on its own but more effective when used in combination with a statin. However, the long term benefits are yet to be proven.

Nicotinic acid - these are very good at raising the HDL cholesterol but is not widely used because of side effects, particularly flushing.

Every effort has been made to ensure that the information on this website is up-to-date and accurate. However, it is intended to serve as a guide only. Symptoms may vary and if you have any medical concerns you should always consult a healthcare professional.