MANY OBESE YOUTH HAVE CONDITION THAT PRECEDES TYPE 2
DIABETES

Studies To Address Obesity-Linked Diabetes in Children

Many obese children and adolescents have impaired glucose
tolerance, a condition that often appears before the
development of type 2 diabetes, according to researchers
funded by the National Institutes of Health (NIH). The
study findings appear in the March 14 issue of "The New
England Journal of Medicine".

"This study suggests that many obese children have a high
risk for developing type 2 diabetes," said HHS Secretary
Tommy G. Thompson. "Researchers have a lot of information
on how to prevent and treat type 2 diabetes in adults, but
we need to find better ways to prevent and treat the
disease in children."

Once seen only in adults, type 2 diabetes has been rising
steadily in children, especially minority adolescents --
African Americans, Hispanic Americans, and Native
Americans, according to reports from clinics around the
country. Although there are no national, population-based
data, studies in Cincinnati, Charleston, Los Angeles, San
Antonio, and other cities indicate that the percentage of
children with newly diagnosed diabetes who are classified
as having type 2 diabetes has risen from less than 5
percent before 1994 to 30-50 percent in subsequent years.

"These results strongly imply that intensive efforts to
reduce obesity in children and youth who have impaired
glucose tolerance will help to prevent their developing
type 2 diabetes," said Duane Alexander, M.D., Director of
the National Institute of Child Health and Human
Development (NICHD). Both NICHD and the National Center
for Research Resources (NCRR), another NIH component,
funded the study. Both agencies are part of the National
Institutes of Health, the HHS agency that sponsors research
to uncover knowledge that will lead to better health for
everyone.

The scientists from Yale University School of Medicine
conducted their study to determine if obese children and
teens have impaired glucose tolerance, which, in adults is
a known risk factor for type 2 diabetes. The researchers
found that the children with impaired glucose tolerance
frequently had insulin resistance, a condition that usually
precedes type 2 diabetes in adults and is characterized by
the inability of fat, muscle, and liver cells to use
insulin properly. Eventually, the insulin-producing cells
of the pancreas cannot keep up with the body's increasing
demand for insulin, glucose builds up in the blood, and
type 2 diabetes begins.

"The epidemic of childhood obesity in the United States has
been accompanied by a marked increase in the frequency of
type 2 diabetes," the study authors wrote.

The researchers tested for impaired glucose tolerance in 55
obese children from 4 to 10 years of age, and 112 obese
adolescents from 11 to 18 years of age. In all, 25 percent
of the children and 21 percent of the adolescents had
impaired glucose tolerance. The researchers also found
that four of the adolescents in the study had silent type 2
diabetes, a form of diabetes that doesn't cause any
symptoms.

"Impaired glucose tolerance is highly prevalent among
children and adolescents with severe obesity, irrespective
of ethnic group," the researchers wrote.

The National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), the part of the NIH with lead
responsibility for diabetes research, is funding clinical
trials to prevent and treat type 2 diabetes in children.
These studies, currently being planned for recruitment next
year, will try to develop ways to stem the rising rate of
type 2 diabetes in children and to treat the disease safely
and effectively in those who do develop it.

The prevention trials will focus on developing cost-
effective interventions that can be widely applied in
schools and communities across the country. "For children
who already have type 2 diabetes, it's critical to give the
safest, most effective therapy as early as possible, yet we
can't assume that the therapies used in adults have the
same safety and efficacy profiles for children," said study
chair Dr. Francine Kaufman, president elect of the American
Diabetes Association and director of the Comprehensive
Diabetes Center at the Children's Hospital of Los Angeles.
Many drugs are available to treat type 2 diabetes, but only
metformin has been explicitly approved by the Food and Drug
Administration for the treatment of type 2 diabetes in
children.

The longer a person has diabetes, the greater the chances
of developing the disabling, life-threatening complications
of diabetes. "We are seeing young people in their late
teens who are already developing the complications of type
2 diabetes," said Dr. Kaufman.

Type 2 diabetes in children, as in adults, is closely
linked to obesity, a sedentary lifestyle, and a family
history of diabetes. The prevalence of obesity has nearly
tripled in adolescents in the past 20 years. According to
"The Surgeon General's Call to Action to Prevent and
Decrease Overweight and Obesity", 13 percent of children 6
to 11 years old and 14 percent of adolescents 12 to 19
years old in the United States were overweight in 1999.
Overweight children are at increased risk of developing
type 2 diabetes during childhood and later in life. Genetic
susceptibility as well as lack of physical activity and
unhealthy eating patterns all play important roles in
determining a child's weight. They also contribute to a
child's risk for type 2 diabetes and other complications of
overweight.

About 16 million people in the United States have diabetes.
It is the main cause of kidney failure, limb amputations,
and new onset blindness in adults and a major cause of
heart disease and stroke. Type 2 diabetes accounts for up
to 95 percent of all diabetes cases. Most common in adults
over age 40, this form of diabetes affects 8 percent of the
U.S. population age 20 and older. The prevalence of type 2
diabetes has tripled in the last 30 years, due in large
part to the upsurge in obesity. People who are obese,
defined as a body mass index (BMI) of 30 or greater have a
five-fold greater risk of diabetes than those with a normal
BMI of 25 or less.

Type 1 diabetes affects about 1 million people in the
United States. This form of diabetes develops when the
body's immune system destroys pancreatic beta cells, the
only cells in the body that make the hormone insulin, which
regulates blood glucose. Type 1 diabetes usually strikes
children and young adults, who need several insulin
injections a day or an insulin pump to survive. Insulin is
the only treatment for type 1 diabetes, but it is not a
cure, nor can it reliably prevent the long-term
complications of the disease.

The National Center for Research Resources (NCRR) supported
this research through grants to Yale University for two
General Clinical Research Centers that host adult and child
studies. NCRR funding provides NIH-supported investigators
with access to specialized basic and clinical research
facilities, technologies, instrumentation, biomaterials,
animal models, genetic stocks, and more.

The NICHD sponsors research on development before and after
birth; maternal, child, and family health; reproductive
biology and population issues; and medical rehabilitation.
NICHD publications, as well as information about the
Institute, are available from the NICHD website,
http://www.nichd.nih.gov, or from the NICHD Clearinghouse,
1-800-370-2943; E-mail NICHDClearinghouse@mail.nih.gov.

The NIDDK conducts and supports basic and clinical research
in endocrine and metabolic diseases, such as diabetes and
obesity; digestive diseases; and kidney, urologic, and
blood diseases. For more information about research and
recent advances in these diseases, see
<http://www.niddk.nih.gov/. For specific information
about diabetes, see "health information" at this website or
call the National Diabetes Information Clearinghouse, 1-
800-860-8747.