ABSTRACT
The definition of type III hyperlipoproteinaemia is difficult; it cannot simply rely on the presence of the cholesterol-rich βVLDL, since this can be detected in some apparently healthy people with normal levels or even low levels of serum cholesterol and triglycerides. For clinical purposes, type III will therefore be considered as the presence of cholesterol-rich βVLDL together with hyperlipidaemia. On the basis of this definition, type III hyperlipoproteinaemia is a rare disorder affecting no more than 1 in 10 000. It is exceptionally unusual to encounter it until the end of the second decade. It tends to be present in men earlier than in women, in whom it frequently does not produce signs until after the menopause. Many patients have some other disorder predisposing them to hyperlipidaemia, such as obesity, diabetes or hypothyroidism, before the clinical syndrome of type III hyperlipoproteinaemia develops. In others, it must be presumed that some other genetic cause of hyperlipidaemia has led to its expression, such as familial hypertriglyceridaemia.
