Hyperlipidaemia, defined as an increase in levels of plasma cholesterol or triglyceride, or of both, is one of the most common metabolic disorders that occurs in industrialised societies. It results from genetic and acquired derangements in the metabolism of plasma lipoproteins. The major significance of hyperlipidaemia, particularly hypercholesterolaemia, is that it is one of the main risk factors for the development of premature atherosclerotic complications (Fig. 6.1), with the principal lipoprotein-related cardiovascular risk factors being increased levels of low-density lipoproteins (LDL) and low levels of high-density lipoproteins (HDL). The role of hypertriglyceridaemia as a risk factor is more complex and may be related more to the cause, rather than to the extent, of the condition.
