Future
Heart Risks Assessed with Kids' Cholesterol Test
Researchers have begun to take a serious look at the long-term
health consequences of children's inactivity by using cholesterol levels as
a window into these youngsters' futures.
Obesity, inactivity, and cholesterol are closely linked,
and data from the latest National Health and Nutrition
Examination Survey (NHANES) finds that 17 percent of US teens are overweight.
Just one in four high school students packs enough physical
activity into their day, and 12 percent get little or no daily exercise, reports
the Centers for Disease Control and Prevention (CDC).
So, measuring kids' cholesterol in a really detailed way
may make sense.
"There is growing scientific evidence indicating that cholesterol
levels in childhood and adolescence have an effect on the development of plaque
in the arteries, which is a clear indication of cardiovascular disease risk," explains
study leader Dr. Ian Janssen, at Queens University in Ontario.
"There is also strong evidence indicating that children
and youth with high cholesterol will continue to have high cholesterol in adulthood," he
adds. "Thus, it is important to start treatment and prevention efforts early."
Using data from the NHANES on
more than 6,000 children ages 12 to 20, Dr. Janssen and his colleagues developed
age- and gender-specific reference points for total cholesterol, LDL ("bad")
cholesterol, HDL ("good") cholesterol, and triglyceride fat levels.
The new tables, published last year in the journal Circulation,
take into account fluctuations in cholesterol and fat that occur as a child
matures.
The new reference data are meant to improve upon current
guidelines, published by the National Cholesterol Education
Program, which do not account for age-related fluctuations.
Still, Dr. Janssen admits that the guidelines have not yet
been routinely adapted into clinical care settings in the US.
"These sorts of changes to clinical practice typically take
years to manifest," he says.
Dr. Marc S. Jacobson, at Schneider Children's Hospital in
New Hyde Park, N.Y., says it is unclear how the new tables will be received
in the US.
"It complicates lives of people like me who treat adolescents
with lipid problems because instead of just having one number, you have to
have four graphs and plot them out by age," he says.
"Instead of having one cut point," he continues, "you
have a graph that you have to plot out a percentile. With each lipid profile,
you
have to decide which percentile this is for that individual's age. And when
it goes up and when it goes down, did it go down because of treatment? Or did
it go down because of advancing puberty?"
The challenge, then, is to make sense of that information,
he explains.
"It argues
that you almost have to take it into account because you could say if the
LDL changes, is it the treatment
or is it a change
in puberty?"
Currently, the federal government recommends cholesterol
screening for children and teens with at least one parent with high cholesterol
or a family history of early heart disease.
"Typically high-risk adolescents should be screened, and
probably every year or two," notes Dr. Janssen. "A high-risk adolescent would
be one who's had a parent or grandparent with premature cardiovascular disease
or high cholesterol, or a teen with other risk factors, such as obesity and
high blood pressure."
Other
risk factors, such as diabetes or smoking, also would trigger cholesterol
testing in physicians' offices, "and that covers a lot
of kids now," says Dr. Jacobson.
The issue is destined to garner greater attention when a National
Heart, Lung, and Blood Institute (NHLBI) panel updates guidelines
on cholesterol screening in children and teens.
The new
guidelines are scheduled for
release in April 2008, says Dr. Rae-Ellen Kavey, in the NHLBI Office
of Prevention, Education, and Control.
"Stay tuned," says Dr. Kavey, "because
there really is going to be new information."
Always consult your physician for more information.
|
