High Cholesterol (Hyperlipidaemia/Hypercholesterolaemia) Patient Information Leaflet
What is cholesterol?
Cholesterol is a fat chemical (lipid) that is made in the cells in your body.
Many different cells make cholesterol but cells in the liver make about a quarter of the total.
You need some cholesterol in the body for normal function.
However, a high levels of cholesterol increases your risks of developing cardiovascular disease by causing the build up of atheroma in blood vessels which lead to narrowing of the arteries. These atheromas can break off and caused interruption of the blood supply to areas of the heart or brain and cause conditions such as heart attacks and strokes.
What are the symptoms?
High cholesterol is often found during routine screening when your doctor is trying to assess your cardiovascular risk as part of an annual health check/screen.
There are not necessarily any symptoms.
However changes that may be visible on your body if you have the inherited form of hyperlipidaemia:
- Premature arcus senilis- a white or grey ring a visible around your eyes
- Tendon xanthomata- these are nodules or fatty deposits found in tendons such as the achilles tendon at the back of your feet
- Xanthelasma- fatty deposits in the eyelids
How is cholesterol measured?
As a high level of cholesterol increases risks of cardiovascular disease, it is common to have your cholesterol levels measured by a simple blood test arranged through your GP as part of a health check or annual health screen.
What do the results mean?
You are normally told what your total cholesterol levels are.
A total cholesterol level under 4 mmol/l is ideal.
However you may also be advised what the breakdown of your cholesterol profile is in terms of your LDL cholesterol, HDL cholesterol and triglycerides.
Cholesterol is carried around the body by proteins, which when combined are called lipoproteins.
There are two main types of lipoproteins:
- Low-density lipoproteins (LDL) is known as the bad type of cholesterol.
- LDL carry cholesterol from your liver to the cells that need it.
- LDL levels below 2 mmol/L are ideal
- Raised levels of bad cholesterol (LDL) in your blood can cause fatty material to build up in your artery walls.
- High-density lipoprotein (HDL) is known as the good type of cholesterol.
- HDL carry cholesterol away from the cells and back to the liver to be broken down.
- HDL levels above 1 mmol/L are ideal
Triglycerides are another type of fat in the body, and raised levels may also place you at increased risks of cardiovascular disease.
They are the main form of fat stored in the body and are the breakdown products of the fats present in our food and are stored in fat cells.
What causes high cholesterol?
There is no one single cause for high cholesterol.
Many different factors can contribute to high cholesterol or increased risks of having high cholesterol and include:
- Diet- to an extent your blood cholesterol level can vary depending on your diet.
- Smoking
- Obesity
- Inactivity
- Excess alcohol
- Diabetes
- Kidney Disease
- Thyroid disease
- Genetic factors: In some people a very high level of cholesterol runs in the family, due to a genetic problem with the way cholesterol is made by the cells in the body. One example is called familial hypercholesterolaemia.
Cardiovascular risk score
A cardiovascular risk calculator called the Australian Absolute Cardiac Risk Score is commonly used by doctors and nurses.
This assesses your cardiovascular health risk.
A score is calculated which takes into account all your risk factors such as age, sex, smoking status, blood pressure, cholesterol level, etc.
This calculates your risk of developing cardiovascular disease over the next 5 years and can be used to help guide management options for treating your high cholesterol.
Risk scores are classified as follows:
<10% LOW RISK
10-15% MODERATE RISK
>15% HIGH RISK
How can I lower my cholesterol?
Lifestyle measures:
- Diet- A low fat and healthy diet with:
- At least 5 portions of fresh fruits/vegetables a day
- 2-3 portions of oily fish per week
- Lean meats (chicken/turkey or lean red meats)
- Reducing intake processed foods, meats, cheeses, fried foods and butter etc and use low fat spreads mono or polyunsaturated
- Low levels of salt (less than 6g/day for an adult)
- Foods that contain plant sterols or stanols can reduce total blood cholesterol level and LDL cholesterol by about 10%. However, there does not seem to be much evidence, however, that this has an effect on preventing cardiovascular disease.
- Exercise- regular exercise amounting to the equivalent of 30 mins exercise 4-5 times per week
- Weight loss
Medication
If you have:
- high risks of developing cardiovascular disease
- had a stroke or heart attack or other cardiovascular disease
- familial hypercholesterolaemia
then medication is usually advised along with advice regarding lifestyle measures.
Medication can be used to lower your cholesterol levels
Statins are the most common type of medications used.
They work by blocking a chemical (enzyme) which is needed to make cholesterol in the liver.
They are usually take once daily at night
Your doctor may wish to re-check your cholesterol levels and liver function after 2-3months of treatment to monitor the effects of the medication
Certain medications (antibiotics, blood pressure medications) and foods such as grapefruit may interact with statins and cause side effects. Your doctor should fully explain this prior to starting statins.
Other medications used to treat high cholesterol include:
- Bile acid sequestrants such as colestyramine prevent bile acid reabsorption from the gut and so the liver uses cholesterol in the blood to replace bile
- Fibrates such as bezafibrate and fenofibrate work well to reduce levels of triglycerides in the blood
- Ezetemibe which is used in combination with statins and works by preventing re-absorption of cholesterol from the gut
- Fish oils may also help to reduce high cholesterol levels but is controversial as the evidence for this remains unclear
