Coronary heart disease

Environmental factors play a very important role in the
aetiology of coronary heart disease, and many risk factors have
been identified, including high dietary fat intake, impaired
glucose tolerance, raised blood pressure, obesity, smoking, lack
of exercise and stress. A positive family history is also
important. The risk to first degree relatives is increased to six
times above that of the general population, indicating a
considerable underlying genetic predisposition. Lipids play a
key role and coronary heart disease is associated with high LDL
cholesterol, high ApoB (the major protein fraction of LDL),
low HDL cholesterol and elevated Lp(a) lipoprotein levels.
High circulating Lp(a) lipoprotein concentration has been
suggested to have a population attributable risk of 28% for
myocardial infarction in men aged under 60. Other risk factors
may include low activity of paraoxonase and increased levels of
homocysteine and plasma fibrinogen.