First 11 pages of thesis. - OPUS - Universität Würzburg

1.2 Risk Factors
Atherosclerosis has a complex aetiology influenced by a number of
factors. The cardiovascular risk increases with the number of risk factors of a
patient. Factors which influence atherosclerosis development can be grouped
into genetic and environmental. In most cases the development of
atherosclerosis results from complex interactions between environmental and
genetic factors.
1.2.1 Factors with a strong genetic component
1. Elevated levels of low density lipoproteins (LDL)
Low density lipoproteins play an important role in transportation of cholesterol
and triglycerides from the liver to peripheral tissues and in the regulation of
cholesterol synthesis. Elevated levels of LDL usually result from mutations in
the LDL receptor gene, causing familial hypercholesterolemia 2 . Some of the
genetic variants which cause elevated LDL levels are the apolipoprotein E 3 and
the apolipoprotein (a) genes 4 .
2. Reduced levels of high density lipoproteins (HDL)
High density lipoproteins carry cholesterol from the systemic circulation to the
liver, where they are excreted or re-utilized. Polymorphisms in the hepatic lipase
encoding gene and the apolipoprotein AI-CIII-AIV gene cluster results in altered
levels of HDL 5 .
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