Management of dyslipidaemia
- Correspondence to:
Professor Gilbert R Thompson
Metabolic Medicine, Imperial College, Hammersmith Hospital, Du Cane Road, London W12 ONN, UK;
Dyslipidaemia is a preferable term to hyperlipidaemia because it includes risk factors such as a decreased concentration of high density lipoprotein (HDL) cholesterol as well as qualitative changes in low density lipoprotein (LDL), notably the presence of small, dense LDL particles. Both abnormalities, together with raised triglycerides, are features of the metabolic syndrome, increasingly recognised as a harbinger of coronary heart disease (CHD).
The simplest classification of dyslipidaemia defines the lipid phenotype as hypercholesterolaemia, hypertriglyceridaemia, or mixed hyperlipidaemia (MHL). Each can result from dysfunctional mutations of dominantly expressed genes encoding receptors, enzymes or transfer proteins involved in lipoprotein metabolism, usually indicated by a familial pattern of inheritance. More often, however, dyslipidaemia reflects the interaction between weaker genetic influences and environmental factors such as diet and a sedentary existence. In these situations the adoption of changes in lifestyle is the first line of treatment whereas monogenically determined dyslipidaemias, such as familial hypercholesterolaemia (FH), usually require lipid regulating drug treatment.
CURRENT GUIDELINES FOR PREVENTING CARDIOVASCULAR DISEASE
Management of dyslipidaemia forms an important part of strategies for preventing cardiovascular disease. Most of the current guidelines reflect the results of the five major statin trials published between 1994 and 1998. Overall, statins reduced the risk of CHD by 31% and total mortality by 21%, benefit being equally evident in men and women below and above the age of 65.1
In addition to a decreased incidence of CHD, a significant decrease in the frequency of strokes was apparent in some of the trials. A meta-analysis of those using simvastatin, lovastatin or pravastatin, involving almost 10 000 patients, showed a 27% decrease in the risk of stroke,2 possibly reflecting a statin induced improvement in cerebrovascular endothelial function.
The joint recommendations of the British Cardiac and Hypertension Societies and the British Hyperlipidaemia and Diabetic Associations, published in 1998,3 advised estimating …