Heart Deaths: Cholesterol a Culprit
Analysis Shows Lowering Total Cholesterol Decreases Deaths From Heart Disease
Nov. 29, 2007 -- High
cholesterol is a major risk factor for death from heart disease, but its impact on stroke death is less clear, a new analysis combining 61
In one of the largest evaluations of the research examining cholesterol and
mortality ever conducted, researchers found lower total cholesterol to be
strongly protective against death from heart attack for both men and women.
Roughly 34,000 deaths from heart disease and 12,000 deaths from stroke were
recorded among the almost 900,000 participants in the studies.
Among adults between ages 40 and 89, a reduction in total cholesterol of 39
mg/dL (or 1 mmol/L) was associated with about a 33% reduction in heart disease
Among those aged 50 to 69 and 70 to 89, respectively, 1 mmol/L lower total
cholesterol was associated with 34% and 17% reductions in the risk of death
from heart disease.
"The message is clear with regard to heart disease," researcher
Sarah Lewington, DPhil, of the University of Oxford, tells WebMD. "If you
are at risk for heart disease or have it, the lower your cholesterol, the
Cholesterol and Stroke Death
But important questions remain about the impact of cholesterol levels on
death from stroke.
While studies of cholesterol-lowering statin drugs unequivocally show the
drugs to be protective against stroke, most observational studies like the ones
included in the latest analysis have failed to show a strong relationship
between blood cholesterol levels and death from stroke.
Some have even shown low total cholesterol to be associated with an
increased risk of death in elderly patients.
"We don't really understand these findings, and they certainly invite
future research," Lewington says. "But the evidence from randomized
trials clearly shows that lowering cholesterol with statins has a positive
impact on stroke risk. No one is saying that lowering cholesterol is bad news
The Message to Patients
American Heart Association (AHA) spokeswoman Barbara V. Howard, PhD, says
despite the confusing findings, it is clear that keeping cholesterol under
control is one of the best ways to avoid heart attack and stroke.
Howard leads the AHA council on nutrition, physical activity, and metabolism
and is president of MedStar Research Institute in Hyattsville, Md.
"Start with diet, exercise, and weight control -- and if that doesn't do
it, medication probably will," she tells WebMD. "There is no question
that lowering cholesterol also lowers stroke risk."
Lewington and colleagues agree that the public health message is
"Treatment should be guided principally by the definitive evidence from
randomized trials, [showing] that statins substantially reduce not only
coronary event rates but also total stroke rates in patients with a wide range
of ages and blood pressures," they write.