Atherosclerosis and cholesterol: What we should know

The relationship between plasma cholesterol levels and the risk of cardiovascular events is well known. When analysing plasma cholesterol levels and integrating data from several studies, including the Pooling Project, the Framingham Heart Study and the Israeli Perspective Study, a consistent association was confirmed worldwide. This pattern was particularly evident in the Seven Countries Study.1 The observed variations in risk across different populations are largely due to the baseline risk values of these populations. For example, the Framingham Heart Study has shown that its results are applicable in any country by adjusting for baseline risk, suggesting a universal pattern in the relationship between cholesterol levels and cardiovascular risk. This has led to debate because the relationship has been oversimplified and presented as linear when it is not necessarily so. For example, an increase in total cholesterol of 0.5 mmol/L (about 20 mg/dL) correlates with a 12% change in mortality risk. In agreement with this observation, data from the Cholesterol Treatment Trialists' (CTT) Collaboration have shown that lowering low-density lipoprotein cholesterol (LDL-C) by 1 mmol/L reduces the risk of coronary heart disease by 22-23% reduction, which is consistent with data from clinical trials.