TUESDAY, April 10 (HealthDay News) -- One clue to your risk for
a stroke may come from a look at your siblings' experience with the
brain attacks, a new study says.
People whose brother or sister had a stroke were up to 64
percent more likely to suffer one, compared to folks without such
family histories, Swedish researchers report.
The risk rose even higher when the stroke to the sibling
occurred when he or she was relatively young. For example, when a
sibling had a stroke before the age of 56, their brother or
sister's risk for a stroke nearly doubled, the study found.
The findings refer to the most common kind of stroke --
so-called ischemic stroke -- which occurs when blood flow is cut
off to the brain as a result of a blood-vessel blockage.
"Patients in the risk zone of getting a heart attack or a stroke should be made aware that a genetic predisposition exists," said study lead author Dr. Erik Ingelsson, a professor of cardiovascular epidemiology at the Karolinska Institute, in Stockholm.
Still, that does not mean that you're doomed to suffer a stroke
if your sibling did, Ingelsson added. "The increased familial risk
may not solely be due to genetics," he said. "Similar lifestyle
within families could also be involved -- and lifestyle can of
course be modified."
The findings are published April 10 in
Circulation: Cardiovascular Genetics.
Roughly 700,000 Americans experience an ischemic stroke every
year, according to the American Heart Association.
To get a handle on sibling-associated stroke risk, the Swedish
team pored through Swedish hospital discharge data and death
registries for the period between 1987 and 2007.
The information included more than 30,700 men and women whose
siblings had experienced a stroke, as well as another roughly
152,000 adults with no history of sibling stroke.
The results: Those whose brother or sister had had a stroke were
between 61 and 64 percent more likely than those with no such
family history to have one themselves.
Those whose half-brother or half-sister had had a stroke faced a
41 percent greater chance of having a stroke.
And those whose siblings had a stroke at the age of 55 or
younger faced a 94 percent bump in their own stroke risk -- a
nearly doubling of risk.
Gender did not appear to play a role in the degree to which
sibling stroke history affected one's own risk.
The study authors stressed that they only looked at stroke
incidence and did not explore family histories for any underlying
risk factors, such as high blood pressure or cholesterol levels.
That means they could not break down the degree to which genetic
factors influenced stroke risk, versus the role played by nurture
-- a shared upbringing.
However, "if your sibling has had a stroke, it may be a good
idea to pay more attention to lifestyle habits such as diet and
exercise, and to have your blood pressure checked at regular
intervals," Ingelsson advised.
Dr. Gregg Fonarow, a professor of cardiology at the University
of California, Los Angeles, said the study was "helpful" in better
understanding stroke risk.
"This gives us insight into family risk, which involves both genetics, in terms of high blood pressure and high cholesterol risk, as well as a history of shared lifestyles," he said.
"Clearly, those with a first-degree relative who has had a stroke earlier in life are at much higher risk themselves, and should be seeking to address all the modifiable risk factors for a stroke," Fonarow added.
Dr. Murray Mittleman, director of the cardiovascular
epidemiology research unit at Beth Israel Deaconess Medical Center
in Boston, said: "Although you can't control your and your
sibling's past history, you can control your current risk through
"That would mean quitting smoking if you're a smoker," he said. "Getting your blood pressure checked and controlling it with medications so it's at a safe level. Maintaining an active lifestyle. And eating a heart-healthy diet with a good balance of healthy fats, fresh fruits and vegetables, and a reasonable amount of fiber."
Find out more about stroke at the
National Stroke Association.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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