A scientific statement from the American Heart Association (AHA)
outlines what is known and what is yet to be learned regarding a
familiar array of cardiometabolic risk factors manifested in children
and adolescents, emphasizing, in particular, that its clinical
implications are poorly understood in that population, especially
compared with what is known about it in adults [1].

Whether combinations of obesity, insulin resistance, lipid
abnormalities, and hypertension in the young actually predict
cardiovascular disease during the adult years is not known, in part
because of a dearth of longitudinal data and some unique challenges
in even defining those conditions in children, according to the
report's writing group, chaired by Dr Julia Steinberger (University
of Minnesota, Minneapolis).

"In adults, we refer to this clustering of risk factors as the
metabolic syndrome, but it hasn't been clear to us that it could be
called the metabolic syndrome in children," Steinberger, a pediatric
cardiologist, told heartwire.

She described the report as an update to a 2003 statement from the
AHA on obesity, insulin resistance, and diabetes in the young [2],
and a "pediatric companion document" to the organization's Diagnosis
and Management of the Metabolic Syndrome consensus statement from
2005 [3]. The report was published online January 12, 2009 by
Circulation and is scheduled for the February 3 issue.

It has been common in pediatric studies to characterize the metabolic
syndrome in terms of definitions used for adults, observed
Steinberger. But that approach, as well as some attempts to create
child-specific definitions, has been limited, among other reasons, by
a lack of outcomes data and variability in the measures of the
different risk factors. It isn't practical to track children long
enough for some of them to develop cardiovascular disease and
experience clinical events, and what's "abnormal" for some will
be "normal" for others.

"In adults, we can use cut points for defining normal and abnormal
levels of the components of the metabolic syndrome," Steinberger
said. "In children it¡¦s a lot more vague because we're talking about
children of different ages and in different stages of development.
Waist circumference, triglycerides, HDL-cholesterol, blood pressure,
fasting glucose--in children these are moving targets, there really
aren't very well established criteria for what is normal or
abnormal."

So the challenge in kids, as reflected in the AHA scientific
statement, is to define who is at risk for disease in adulthood in
terms of the different risk factors, with less attention paid to
establishing criteria for defining a specific syndrome, according to
Steinberger. Whereas in adults there is a focus on the treatment of
disease resulting from the metabolic syndrome, she said, in kids the
focus is on prevention and management of obesity and the other risk
factors.

"Because specific treatment aimed at the underlying pathophysiology
of the metabolic syndrome does not yet exist, other than reducing
adiposity and increasing physical activity, therapy targeted at each
of the risk factors present is of importance. This treatment strategy
would not be improved by labeling a patient dichotomously as having
the metabolic syndrome," according to the statement.

"What is probably needed is not a dichotomous definition but a more
complex weighted scoring system that takes into account the magnitude
of all of the risk factors, their interaction, and other important
patient characteristics, including family history."

Steinberger reports receiving research grants from Pfizer and Sankyo.
Disclosures for other members of the statement's writing group are in
the report.

Steinberger J, Daniels SR, Eckel RH, et al. Progress and challenges
in metabolic syndrome in children and adolescents. A scientific
statement from the American Heart Association Atherosclerosis,
Hypertension, and Obesity in the Young Committee of the Council on
Cardiovascular Disease in the Young; Council on Cardiovascular
Nursing; and Council on Nutrition, Physical Activity, and Metabolism.
Circulation; published online before print January 12, 2009. Abstract
Steinberger J, Daniels SR. Obesity, insulin resistance, diabetes and
cardiovascular risk in children: an American Heart Association
scientific statement from the Atherosclerosis, Hypertension, and
Obesity in the Young Committee (Council on Cardiovascular Disease in
the Young) and the Diabetes Committee (Council on Nutrition, Physical
Activity, and Metabolism). Circulation 2003; 107:1448 ¡V1453.
Abstract
Grundy SM, Cleeman JI, Daniels SR, et al. Diagnosis and management of
the metabolic syndrome: an American Heart Association/National Heart,
Lung, and Blood Institute Scientific Statement. Circulation 2005;
112:2735¡V2752. Abstract