Clinical investigations have shown that lowering the "total serum cholesterol" levels result in a significant reduction of coronary artery disease and myocardial infarctions . Thus, interventions to lower the "total serum cholesterol" are commonly employed by medical professionals - this includes behavioral modifications (exercise, dieting, and weight loss) and pharmacological interventions.
Investigation has shown that clinical outcomes do not only rely on "total serum cholesterol". "Total serum cholesterol" is comprised of multiple subtypes - most notable are "HDL Cholesterol" and "LDL cholesterol". Analysis of the data has shown that high levels of LDL cholesterol predict higher rates of cardiovascular events, while high levels of HDL cholesterol are actually predictive of significantly less cardiovascular events. These effects are independent of other cardiovascular risk factors .
The mechanism by which LDL cholesterol results in heart disease has been intensely investigated and elucidated. Numerous drugs are now approved and utilized by physicians to lower the LDL cholesterol of patients to prevent primary and secondary cardiovascular disease.
Epidemiological data show that low levels of HDL-C place individuals at higher risk for coronary artery disease while high levels of HDL-C actually decrease an individual's risk . The mechanism behind this risk reduction remains unclear and is likely multi-factorial. Furthermore, some data suggests that while HDL-C is important in risk reduction, it is not necessarily the measured serum level of HDL-C, but also the composition, oxidation state, metabolism of the HDL-C that determines an individual's cardiac risk . Understanding of this mechanism could lead to potential therapeutic targets as well as clinically relevant diagnostic testing.
