Friday, April 27, 2007

Overweight and Overlooked: A Hidden Heart Risk for Kids

Ron Winslow, Wall Street Journal

Heart researchers say they have uncovered a surprising development in the
obesity epidemic: Overweight children who go undiagnosed at the doctor's
office but who are in fact in the early stages of heart disease.

At Cincinnati Children's Hospital Medical Center, researchers found that a
number of kids viewed as normal, healthy children by their parents and even
the medical staff at the hospital were later found to have enlarged hearts
-- a thickening in the wall of the main pumping chamber. Even some children
under 10 years old showed signs of the condition, known as left ventricular
hypertrophy, or LVH.

When researchers went back later to look for clues, they calculated these
children's body mass indexes and found that many were actually overweight.
Research has previously detected enlarged hearts in children, but generally
in those who were clearly obese. What surprised the Cincinnati Children's
researchers is that they found LVH in children whom doctors hadn't initially
deemed overweight.

Given the attention on childhood obesity today, how could doctors not notice
that these kids were heavy? One argument is that there are so many of them.

"We've grown so accustomed to an overweight child walking into the exam room
that we've lost our visual representation of what a normal child is supposed
to look like," says Tom Kimball, a pediatric cardiologist at the hospital.
In short, overweight is the new "normal."

Doctors rarely look for enlarged hearts in kids. But in adults, LVH is an
important sign of heightened risk of cardiovascular disease. The worry in
kids is that, left unmanaged, these early physical changes to the heart
could set children on a life course for premature coronary artery disease
and heart attacks.

"We found that kids we consider 'normal' actually are not, from a
cardiovascular standpoint," says Sandy Witt, a cardiac sonographer at
Cincinnati Children's. "But no one is alerting the children or the families.
Even for the physician, it is going under the radar."

Spurred by the concerns about overlooked obesity in kids, Ms. Witt and her
colleagues conducted further research that showed an overall rise in
children's BMIs in recent years, and linked high BMI with risk for an
enlarged heart.

The report, which researchers presented at the recent American College of
Cardiology meeting in New Orleans, is based on a comparison of children that
doctors viewed as normal during the past three years with a similar group
from the late 1980s.

The findings heighten the stakes in an already intense struggle under way in
homes, schools and communities over how to encourage kids and their families
to change eating, exercise and other habits to promote better health.

Dr. Kimball says fewer cases of overweight children would be missed if
doctors routinely calculated their patients' body mass index -- a ratio
based on height and weight. Both the American Academy of Pediatrics and the
U.S. Centers for Disease Control and Prevention recommend doctors chart and
track BMI for children, but the indicator isn't perfect and for a variety of
reasons, not widely used, Dr. Kimball says. For one, muscle mass can vary
widely in kids.

Though there are exceptions, those whose BMI is above the 95th percentile
for their age are generally considered overweight; above the 85th percentile
is at risk of being overweight.

Dr. Kimball and his colleagues conducted the study after making a curious
observation among some 50 seemingly normal children who were recruited to
serve as a control group for a clinical study. The trial was to look at the
effect of high blood pressure on children's hearts. As part of the
assessment, researchers took the kids' height, weight and blood pressure,
but didn't calculate their BMI or otherwise identify them as overweight.
They didn't look overweight, says Ms. Witt, the sonographer.

But when the researchers performed an echocardiogram -- an ultrasound image
of the heart -- they found that in many of the kids their hearts were
enlarged. "None of these kids seemed to be somebody who would have that,"
she says. In trying to understand why the children's hearts were enlarged,
researchers calculated the BMIs. "They all seemed like normal, healthy kids,
but when we calculated their BMI, they weren't normal."

Many of these recruits were children of doctors and other staff at the
hospital. When they were told about the echocardiogram findings, "it came as
a surprise to them," says Ms. Witt.

The researchers figured that a look at a previous generation of the
hospital's patients might offer an answer, she says.

Using the hospital's database, they culled data on 465 children between the
ages of 2 and 17 who had undergone echocardiogram exams between 1984 and
1990 -- a period shortly before the sharp rise in childhood obesity began --
and 548 kids of similar age from the current era, 2004 to 2006. All told,
the study included 559 boys and 444 girls.

The kids had all been deemed healthy from a cardiovascular standpoint. Kids
in each group had been evaluated for heart murmurs or chest pain that turned
out not to have a cardiac cause and they had been found to be free of any
signs of heart disease. The researchers compared them on both BMI and what
their echocardiograms revealed about thickening in their left ventricles.

Body mass index among kids in the most recent group was 18.8 on average,
compared with 17.9 in the group from the 1980s. The echocardiograms revealed
a 10% increase in left ventricular mass in the current group compared with
their earlier counterparts.

While body mass in children is influenced by numerous factors, the
researchers said that even after accounting for two prominent ones -- male
gender and age -- the higher body mass index among the kids in the study
correlated significantly with enlarged hearts. "The higher your BMI, the
worse your hypertrophy," Dr. Kimball says.

Exactly what impact that has on future risk isn't clear. "I don't think
anybody has data on how this would translate into cardiovascular issues as
adults," Dr. Kimball says. But it was enough to prompt him to change his
practice. He now carefully charts his patients' BMI and counsels them and
their parents about weight-losing strategies.

The study has limitations. For one, it looked at a limited, nonrandom group
of kids -- all treated at Cincinnati Children's and mostly from southwestern
Ohio and northern Kentucky.

But Christopher Bolling, medical director of the hospital's
weight-management center who was in private practice until 18 months ago,
believes many kids aren't getting appropriate advice in community doctors'
offices either.

"Pediatricians don't know how to bring it up with parents," Dr. Bolling
says. "They're afraid to alienate them or they don't know where to send
them" for help.

The good news is that other research indicates that by losing weight, kids
can reverse the deleterious physical effects on the heart as well as other
weight-related risks for cardiovascular disease.

In a recent study of extremely obese adolescents who underwent bariatric
surgery to treat their condition, weight loss led to a shrinking of the
hypertrophy, says Holly Ippisch, a pediatric cardiologist also at Cincinnati
Children's. She says such benefits would occur regardless of how children
shed weight.

"The important thing is to lose the weight," she says.



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