Raised HDL Cholesterol Less Protective in Those with Low LDL

The researchers from the USA, Canada, Denmark and The Netherlands addressed, using the JUPITER trial cohort, whether this association remains when LDL-cholesterol concentrations are reduced to the very low ranges with high-dose statin treatment. Participants in the randomized placebo-controlled JUPITER trial were adults without diabetes or previous cardiovascular disease, and had baseline concentrations of LDL cholesterol of less than 3.37 mmol/L and high-sensitivity C-reactive protein of 2 mg/L or more. Participants were randomly allocated by a computer-generated sequence to receive rosuvastatin 20 mg per day or placebo, with participants and adjudicators masked to treatment assignment.

For, 17,802 patients in the JUPITER trial, rosuvastatin 20 mg per day reduced the incidence of the primary endpoint by 44% (significant). In 50% of patients given placebo, HDL- cholesterol concentrations were inversely related to vascular risk both at baseline and on-treatment. By contrast, among the 50% of patients given rosuvastatin 20 mg no significant relationships were noted between quartiles of HDL-cholesterol concentration and vascular risk either at baseline or on treatment. The analyses for apolipoprotein A1 showed an equivalent strong relation to frequency of primary outcomes in the placebo group but little association in the rosuvastatin group.

The researchers concluded, "Although measurement of HDL-cholesterol concentration is useful as part of initial cardiovascular risk assessment, HDL-cholesterol concentrations are not predictive of residual vascular risk among patients treated with potent statin therapy who attain very low concentrations of LDL cholesterol."

Low HDL levels do not explain the residual cardiovascular risk in those who have their LDL levels lowered by statins. This does not apply to patients who do not have low LDL levels.

The Lancet published online July 22, 2010. For the full abstract, click here.