By Penny Stern, MD
NEW YORK, Mar 07 (Reuters Health) -- Knowing your cholesterol level has long
been regarded as an important part of assessing your risk of heart disease. Now,
from researchers at the University of Illinois at Urbana-Champaign, comes word
that cholesterol levels may not be good predictors of heart risk after all.
A team of researchers led by Dr. Fred A. Kummerow found that levels of
oxysterols, breakdown products of cholesterol metabolism, may be more sensitive
markers of heart disease.
It is important to recognize, Kummerow told Reuters Health, "that coronary
heart disease is more complex than a plasma cholesterol level indicates."
"The blood of everyone contains oxysterols," he explained, but he added that
his team found higher levels of oxysterols in patients with heart disease than
in patients with healthy coronary arteries.
Cardiac catheterization is an imaging study doctors use to study the health
of arteries feeding the heart. Of more than 1,200 patients who underwent cardiac
catheterization, over 500 of the men later underwent coronary artery bypass
surgery. Interestingly, only 14% were found to have cholesterol levels above the
high normal cut-off of 240. Of the 244 women requiring bypass surgery, some 32%
had cholesterol levels above 240.
This demonstrates that cholesterol levels alone do not always indicate the
degree of heart disease present in an individual patient, the study authors
write in the journal Atherosclerosis.
As Kummerow pointed out, "at present, cardiac catheterization is the only
sure way to identify coronary artery (narrowing) severe enough to cause heart
disease."
But measuring oxysterols is still available only on a research basis. "The
possibility that oxysterol levels may better reflect a patient's true heart
disease status is exciting, although the determination of plasma oxysterols is
(currently) too complex for clinical use," Kummerow noted.
His team's next step will be "to determine why the plasma oxysterol levels
are higher in patients (who need) bypass surgery," Kummerow said.
Nevertheless, he does offer one recommendation to people interested in
controlling oxysterol levels: "increase vegetable and fruit intake."
Antioxidants in fruits and vegetables can reduce oxysterol production and slow
down the calcification process that is part of "hardening of the arteries."
