Risk of CHD is directly related to blood cholesterol levels.   Blood cholesterol levels can be reduced by drugs, physical activity and by dietary changes, in particular a reduction in the consumption of saturated fat.

Research from the World Health Organization highlights the importance of raised blood cholesterol as a risk factor for CHD. The World Health Report 2002 estimates that around 8% of all disease burden in developed countries is caused by raised blood cholesterol, and that over 60% of CHD and around 40% of ischaemic stroke in developed countries is due to total blood cholesterol levels in excess of the theoretical minimum (3.8mmol/l).

More recently the INTERHEART case-control study estimated that 45% of heart attacks in Western Europe and 35% of heart attacks in Central and Eastern Europe are due to abnormal blood lipids, and that those with abnormal lipids are at over three times the risk of a heart attack compared to those with normal lipids.

Different guidelines give slightly different advice for managing high levels of blood cholesterol (hyperlipidaemia). The National Service Framework for coronary heart disease includes guidelines on the prevention of CHD in clinical practice and suggests a cholesterol target of less than 5.0mmol/l for both primary and secondary prevention.  More recent guidelines suggest a target for total cholesterol of less than 4.0mmol/l for individuals with established cardiovascular disease, diabetes, or at high risk of developing cardiovascular disease.

High-density lipoprotein cholesterol (HDL-cholesterol) is the fraction of cholesterol that removes cholesterol (via the liver) from the blood. Low levels of HDL-cholesterol are associated with an increased risk of CHD and a worse prognosis after a heart attack. Guidelines on HDL-cholesterol generally recommend treatment for those with concentrations below 1.0mmol/l.