Triglycerides Linked to Risk for Heart Disease
High levels of triglycerides are strong predictors of
cardiac trouble and this strengthens the case for including measurement of the
blood fats in prevention programs, says a study in the
Journal of the American College of Cardiology.
"Triglycerides traditionally have been viewed as
second-class citizens," says lead author Dr. Michael Miller, at the University
of Maryland Medical Center.
"LDL cholesterol has always taken center stage," says Dr.
Miller. "We know that LDL is intimately involved in bringing cholesterol to
scavenger cells, which deposit them to form plaques in the arteries.
"This study shows that triglycerides in and of themselves
are also lipids to blame," notes Dr. Miller.
The original study was designed to test the effectiveness
of two LDL-lowering statins called Pravachol® and Lipitor® in reducing recurring
coronary disease after a heart attack.
The new study went over the data on the 4,162 participants
in the trial, looking at the association between triglyceride levels and the
incidence of heart problems and death.
"The patients who had heart attacks came back after 30
days," says Dr. Miller. "We measured LDL levels and triglyceride levels and
followed them over the next two years, evaluating for the occurrence of new
events and death. If a patient had triglyceride levels below 150 [milligrams per
deciliter], there was a 27 percent lower risk of having a new event over time,"
he says.
"After multiple adjustments for such things as age,
diabetes, high blood pressure, and obesity, the risk reduction was 20 percent,"
Dr. Miller explains.
Unlike LDL cholesterol, for which there is a recommended
blood level of 70 or below, there is no recommended blood triglyceride level but
150 milligrams per deciliter or below is "considered as desirable," says Dr.
Miller.
When the participants were divided into four groups on the
basis of both LDL and triglyceride levels, those in the group with under 150 for
triglycerides and under 70 for LDL did the best.
They had a 28 percent lower risk than those in the group
with the highest readings for both LDL and triglycerides, he says.
"At the present time, we don't have a recommendation for
triglyceride lowering, so the next logical step is a study to determine whether
lowering triglycerides and LDL reduces risk more than lowering LDL alone," he
says. Two such studies are in progress, he notes.
Previous research has already pointed toward such a
connection: A study that appeared in the medical journal
Neurology last December found a link between triglycerides and stroke
risk.
And research published in the
Journal of the American Medical Association (JAMA) last July showed that
when high triglyceride levels showed up in nonfasting cholesterol tests, there
was an increased risk for a future heart attack.
Dr. Leslie Cho of the Women's Cardiovascular Center at the
Cleveland Clinic, notes that the new report "is not a huge surprise."
She says, "The unique thing about this study is that even
if you control bad LDL cholesterol to less than 70, you still need to look at
triglycerides."
The problem with triglycerides is that "they are the most
unstable fats in the body," so that at least two readings are needed to get an
accurate measure of blood levels, she explains.
Dr. Miller says, "I am proactive about both LDL cholesterol
and triglycerides."
Several measures can be taken to lower triglyceride levels
- many of them are already recommended on general principles for reduction of
coronary risk.
One is to eat a Mediterranean diet, rich in fish. Omega-3
fatty acids can lower triglyceride levels, as can niacin, and exercise has a
beneficial effect, says Dr. Miller. Statins also have some triglyceride-lowering
effect, he notes.
"If you can effectively get both LDL cholesterol and
triglycerides down, you are going to do better," says Dr. Miller.
Always consult your physician for more information.
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