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Facts of Hyperlipidaemia and lipid-lowering medicines

The major lipids in the bloodstream are cholesterol and triglycerides. Lipid- lowering medicines are used to lower cholesterol and triglycerides. Cholesterol and triglycerides occur naturally in your body and certain levels are vital as an energy source, for regeneration of cells and for normal hormone production and growth.

Cholesterol is a fatty substance in your blood. Cholesterol is mostly made in your liver from the saturated fat you eat. Only a small amount comes directly from cholesterol in food. Cholesterol is transported around your body in the bloodstream attached to a protein (lipoprotein).

There are three types of lipoprotein, depending on how much protein there is in relation to fat:

  • low density lipoprotein (LDL) - accounting for 60-70% of total cholesterol,
  • high density lipoproteins (HDL) – accounting for 20-30% of total cholesterol, 
  • and very low density lipoproteins (VLDL) that are rich in triglycerides and account for 10-15% of total cholesterol.

If there is too much LDL cholesterol in your blood it can accumulate in the walls of your blood vessels, causing a build up of plaques (fatty deposits of cholesterol, cell waste and other substances, which form raised patches on the artery wall) leading to narrowing (atherosclerosis), and possible blocking of the artery. Blocked arteries can lead to heart attacks, strokes and death. A high level of LDL cholesterol increases the risk of CHD and stroke. LDL is sometimes referred to as ‘bad cholesterol’.

High levels of HDL cholesterol appear to help to protect against the development of narrowing of arteries. Low levels of HDL may indicate that you may have a greater risk of atherosclerosis. HDL is sometimes referred to as ‘good cholesterol’.

 In some people an increase in LDL cholesterol is accompanied by raised triglyceride levels. Triglycerides are made in the body from the food you eat. People with high triglycerides often have high LDL cholesterol and low HDL cholesterol levels. Many people with heart disease have high triglyceride levels.

 High levels of cholesterol or triglycerides can be caused by:

  • Some common medical conditions such as diabetes mellitus, under active thyroid, kidney disease and liver disease.
  • Having a gene that makes hyperlipidaemia more likely.
  • Certain medications including diuretics, blood pressure medications, prednisone, oestrogens and testosterone.
  • A diet high in saturated fats.
  • Taking no exercise.
  • Excess alcohol intake.