Gene
Linked with Risk of Heart Disease and Stroke in Women
Researchers have identified a gene variant associated with
the early signs of heart disease and stroke in women, according to a report
in the journal Arteriosclerosis, Thrombosis and Vascular
Biology.
None of the more than 11,000 participants in the 25-year
study has yet had heart disease or a stroke, but the signs point toward increased
risk, says study author Dr. Edward Lammer, a pediatrician and geneticist at
the Children's Hospital Oakland Research Institute in California.
"We found changes in two blood vessel areas," says Dr. Lammer. "In
the coronary arteries, we found calcification. We also found thickening of
the carotid arteries in the neck."
A buildup of calcium makes the coronary arteries less flexible
and more vulnerable to damage. Thickening of the carotid arteries, the main
blood vessels to the brain, can be a prelude to a stroke.
Those changes have been seen only in women.
"We have no idea why," says
Dr. Lammer, although it is possible that the signs of risk will develop later
in men than in women.
Now, the researchers must wait to see whether women in whom
the changes have been seen develop cardiovascular problems.
They have not so far, probably because they are too young,
notes Dr. Lammer. The study began in 1971 and has followed 11,377 residents
of Muscatine, Iowa, since their early teens. The Oakland researchers are working
with physicians at the University of Iowa on the study.
Dr. Lammer and his colleagues measured about 100 gene variants
in the study participants.
One of them, designated LTC4S, has been found to be associated
with a fourfold increased risk of the early signs of heart disease and stroke,
after adjustment for standard risk factors such as smoking, cholesterol, and
blood pressure levels.
"What's intriguing is that the gene variant we found is
involved in regulating the inflammatory response," he says. "A research group
from Iceland has reported that two genes in the same pathway are risk factors
for stroke. This gene generates leukotrienes, chemicals that mediate the inflammatory
response."
The LTC4S
gene variant has previously been associated with asthma, "which in essence is an inflammatory reaction," Dr.
Lammer says.
"The hope is that our early results keep the finger pointed
at the role of inflammation regulation as very important for atherosclerosis,
heart disease, and stroke," notes Dr. Lammer.
The fact that the link between the gene variant and the
danger signs seen so far is not associated with standard risk factors could
make gene testing an important part of early risk assessment for many Americans,
says Dr. Lammer.
"About half the people in the study appear to have this
variant," he says.
Dr. Lammer and his associates are continuing to follow the
people in the study to check on the incidence of heart disease and stroke associated
with the gene variant.
"If it is a risk factor that is genetic, we could identify
the risk factor very early in life and develop interventions, behavioral changes,
or medications that ameliorate the risk," he says.
Always consult your physician for more information.
|
