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.
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About 107 million American adults have total blood cholesterol levels of 200mg/dL (milligrams per deciliter) and higher, and of those about 38 million American adults have level of 240 or above.
Elevated cholesterol levels early in life may play a role in the development of adult atherosclerosis.
Cholesterol is a waxy substance that can be found in all parts of your body. It aids in the production of cell membranes, some hormones, and vitamin D.
The cholesterol in your blood comes from two sources: the foods you eat and your liver.
However, your liver makes all of the cholesterol your body needs.
Cholesterol and other fats are transported in your blood stream in the form of spherical particles called lipoproteins.
The two most commonly known lipoproteins are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
LDL
is commonly called the "bad" cholesterol, and is a
type of fat in the blood that contains the most cholesterol.
It can contribute to the formation of plaque buildup in the arteries, known as atherosclerosis.
HDL
is known as the "good" cholesterol, and is a type of
fat in the blood that helps to remove cholesterol from
the blood, preventing the fatty buildup and formation
of plaque.
According to the American Heart Association, high blood cholesterol that runs in families will affect the future of an unknown (but probably large) number of children.
Triglycerides are another class of fat found in the bloodstream.
The bulk of your body's fat tissue is in the form of triglycerides.
The link between triglycerides and heart disease is under clinical investigation.
However, many people with high triglycerides also have other risk factors such as high LDL levels or low HDL levels.
Elevated triglyceride levels may be caused by medical conditions such as diabetes, hypothyroidism, kidney disease, or liver disease.
Dietary causes of elevated triglyceride levels may include obesity and high intakes of fat, alcohol, and concentrated sweets.
A healthy triglyceride level is less than 150 mg/dL.
Always consult your physician for more information.
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