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Department
of Podiatry - Vascular Assessment
Hyperlipidaemia
Cholesterol
crystallites, x50 magnification
Hyperlipidaemia
(hyper + lipos, fat; haima, blood) is excess lipids
(triglycerides and/or cholesterol) in blood plasma. Lipids are transported
in the blood as lipoproteins attached to apoproteins. Cotran et al (1999)
identifies 5 phenotypes of genetically based dyslipoproteinaemias that
result in hyperlipidaemia, however the condition may also result from
other underlying disorders such as nephrotic syndrome, alcoholism, hypothyroidism,
and diabetes. They identify low-density lipoprotein (LDL) cholesterol
as being the major component of the total serum cholesterol. In contrast,
the body also has high-density lipoprotein (HDL) cholesterol.
Hyperlipidaemia is considered a major risk factor for atherosclerosis
(Cotran, 1999; Bowker et al, 2001). It is considered that high LDL levels
contribute to development of atherosclerotic plaques, whereas HDL’s
actually mobilizes cholesterol from vessel walls and transports it to
the liver for breakdown and excretion. Therefore, treatment of hyperlipidaemia
involves lowering LDL’s and raising HDL’s. Exercise and moderate
alcohol consumption raise HDL’s, compared to smoking and obesity
which lower HDL’s (Cotran, 1999).
As discussed in the heart disease section,
atherosclerosis can have major secondary complications.
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