Increasing the level of HDL ("good") cholesterol by itself is enough to reduce cardiovascular risk in certain people, according to a report from Scotland.
Researchers found "evidence of an independent benefit of raising HDL, but for some reason it was only clearly seen in those without established cardiovascular disease and those who took lipid-lowering therapy," Dr. Thomas M. MacDonald from Ninewells Hospital and Medical School, Dundee, told Reuters Health.
MacDonald and his colleagues investigated whether a rise in HDL cholesterol predicted a fall in cardiovascular events such as heart attack, stroke or heart failure, independently of total cholesterol.
"What we did was to correlate the change in HDL in patients in our population with outcome, independent of changes in LDL (we adjusted for this)," MacDonald explained. The findings are reported in the journal Heart.
For patients without a history of cardiovascular illness, the rate of cardiovascular events was lowest among patients with the greatest rise in HDL level, and highest among patients whose HDL level did not change or fell.
Among patients with prior cardiovascular events, the changes in HDL level did not correlate with the risk for subsequent cardiovascular events, the results indicate. The investigators think this may be because the greater use of medication to prevent recurrences in this group may have masked the effect of HDL.
In the group with no prior cardiovascular events, "patients untreated with lipid-lowering drug had lower event rates than did patients who received lipid-lowering treatment," the investigators write. "This is likely to reflect the guidelines for treatment that targeted treatment towards those at high cardiovascular risk."
From these results, MacDonald concluded, "We found that raising HDL independently seems overall to improve cardiovascular outcome."