Dyslipidemia and Cardiovascular Risk: Lipid Ratios as Risk Factors for Cardiovascular Disease

There are extensive epidemiological data demonstrating that high blood cholesterol levels increase cardiovascular risk, and that this risk is dependent on the levels of the different blood cholesterol fractions. Moreover, the reduction of total blood cholesterol has been clearly related to a reduction in the risk of stroke, coronary disease and overall cardiovascular death. However, the traditional cholesterol measurements tend to be most accurate at predicting risk for those at the lower and higher ends of the risk spectrum. Recent data has shown LDL-Cholesterol/HDL-Cholesterol ratio and even TotalCholesterol/HDL-Cholesterol ratio, to be accurate predictors of cardiovascular risk. In fact, changes in ratios have been shown to be better indicators of successful CHD risk reduction than changes in absolute levels of lipids or lipoproteins. In the Helsinki Study, the LDLC/HDL-C ratio had more prognostic value than LDL-C or HDL-C alone (Manninen, Tenkanen, Koskinen et al, 1992). The ratio was especially accurate at predicting risk among those who also had elevated triglyceride levels. The PROSPER trial, a retrospective analysis of 6,000 patients, found that the ratio of LDL-C/HDL-C was the most powerful measure of cardiovascular disease risk in elderly people (Packard, Ford, Robertson et al, 2005). The PROCAM Study, which included almost 11,000 men aged 36 to 65 who were studied for 4 to 14 years, found a continuous and graded relationship between the LDL-C/HDL-C ratio and CVD mortality (Cullen, Schulte, Assmann et al, 1997). In addition, comparison of individual LDL-C/HDL-C ratios from subjects in the Framingham Study clearly indicates that these ratios are significantly more robust predictors of CVD than the individual levels of LDL-C or HDL-C (Kannel, 2005).