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Boys, Blacks
at Higher Risk of Childhood Stroke
By Ed Edelson
HealthDay Reporter
(HealthDay is the new name for
HealthScoutNews.)
MONDAY, July 21, 2003 (HealthDayNews) -- The first large-scale study of
stroke in children finds boys are more likely to have them than girls, and
black children have twice the risk of other ethnic groups.
I t is a more common affliction
than generally believed, says study author Dr. Heather J. Fullerton, a
clinical instructor in neurology at the University of California in San
Francisco. In fact, the study, which appears in the July 22 issue of
Neurology, states that "stroke is an increasingly recognized cause of
childhood disability."
Fullerton and her colleagues looked at all the California hospital
admissions for stroke in patients aged 1 month through 19 years and found
2,278 cases, an incidence of 2.3 in 100,000. The incidence of ischemic
stroke, caused by an artery blockage, and hemorrhagic stroke, caused by a
burst artery, was almost identical.
The overall incidence was about as expected, Fullerton says. Previous
studies have reported an incidence in the neighborhood of 2.5 per 100,000,
"but they did not look at ethnic incidence, and they had a much smaller
number of patients." Differences quickly emerged when the researchers broke
the incidence down by sex and ethnic group. To start with, the incidence was
28 percent higher for boys than for girls. That is understandable to
some degree, Fullerton says, because boys roughhouse more than girls.
Evidence of trauma -- head damage -- was found in twice as many boy patients
as girls.
"But it didn't seem that trauma fully accounted for the difference, so we
think that something else must be involved," Fullerton says. It is known
that adult men have a higher risk of stroke than women, which has been
explained by a higher incidence of risk factors such as diabetes and high
blood pressure, but it would be "sheer speculation" to extend that
explanation to children, she says.
The most striking difference was by ethnic groups. Hispanic children had
a lower incidence than whites, Asians were on a level with whites and black
children had double that risk. The severity of strokes, as measured by the
number of days spent in the hospital, was the same for all the groups.
Again, there is a partial explanation for the racial difference. Black
children are much more likely to have sickle cell disease, which raises the
risk of stroke. Yet when sickle cell disease was taken out of the equation,
the risk for black children was still more than 60 percent higher. There is
no obvious reason for that difference, Fullerton says.
The San Francisco group will seek explanations, she says. "The study we
plan on doing will be a population-based study at childhood stroke that will
look at a number of risk factors that may not have been identified," she
says. "Finding an explanation will take a while."
More information:
An organization that offers information and assistance is the
Pediatric Stroke Network. Learn more about
stroke in children from the
National Institute of Neurological Disorders and Stroke.
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Black and
Hispanic Children Are more Insulin-Resistant than White Kids, Study Says
By Marie Love Darbouze
I n a study of 57 healthy children living in
Los Angeles, black and Hispanic children were shown to be at greater risk for
developing insulin resistance than white kids, according to researchers at the
University of Southern California. This loss of sensitivity to insulin
-- a hormone that regulates the levels of blood sugar (glucose) in the body --i
seems to indicate that ethnicity and genetics may be contributing
factors to the development of type 2 diabetes in these segments of the U.S.
population.
Researchers at the Keck School of Medicine at
USC performed tests on 14 white children, 15 African Americans and 28
Hispanics who ranged in age from 8 to 12. The researchers adjusted for the
effect of total body fat, because this is the leading contributor to insulin
sensitivity. Intravenous injections of glucose were given to the
children, to measure their insulin response to the glucose injection.
The researchers found that the black and
Hispanic children were more insulin-resistant than whites, meaning the tissues
of the body become less responsive to the action of insulin. With reduced
sensitivity to insulin, the body usually compensates by having the pancreas
secrete more insulin. Type 2 diabetes develops when the pancreas fails to
sustain the increased need for insulin secretion, and glucose builds up in the
bloodstream.
The researchers found that Hispanic and black
children had high levels of insulin in the bloodstream. They believed though
these insulin elevations were from different mechanisms. Hispanic
children tended to have more insulin circulating in their bloodstream because
their bodies responded to resistance by pumping out lots of insulin, while
in the black children the researchers believed the children's livers
were removing less of the insulin from the blood circulation.
The researchers said it was important to
consider these differences when developing therapies to treat the disease.
Type 2 diabetes is twice as common among blacks and Hispanics compared to
whites, according to the American Diabetes Association. More and more
teenagers are now being diagnosed with the illness.
SOURCE: Diabetes Care 2002;25:2184-2190
Reviewed by Carl Gilbert, M.D.
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