Diabetes Dateline
Type 2 Diabetes in Childhood: A New
Type of Diabetes Appears Among Minority Youth
Over the past two decades, clinicians and researchers have been increasingly
alarmed by the prevalence of type 2 diabetes among young people of color
around the world. In North America, significant numbers of African Americans,
Alaska Natives, American Indians, Asian and Pacific Islander Americans,
and Hispanic Americans have acquired insulin-resistant diabetes at a much
younger age than is usual for type 2 (adult onset) diabetes.
As noted in the article "Emerging Epidemic of Type 2 Diabetes in
Youth" (Diabetes Care, February 1999, 22[2]), "Prevention
and treatment of type 2 diabetes in children and youth is a daunting challenge
because of the enormous behavioral influence, difficulty in reversing
obesity, and typical nonadherence in this age group."
Type 2 diabetes in childhood presents frustrating puzzles to researchers
and clinicians. For starters, they have yet to agree on a formal definition
of the disease. Type 2 diabetes in childhood is such a recent phenomenon
that youth are mostly diagnosed by accident: for example, they are discovered
during screening as part of prevention programs. We know very little about
the natural history of the disease, partly because patients have not been
followed long enough to learn about long-term complications. Affected
populations may have unique genetic backgrounds.
The February 1998 issue of Clinical Pediatrics reported on a meeting
of researchers and clinicians who gathered to discuss type 2 diabetes
in childhood at the Native American Research and Training Center at the
University of Arizona. The conference was jointly supported by the National
Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the
National Institutes of Health, the U.S. Office of Minority Health, the
Diabetes Action Research and Education Foundation, and LifeScan Inc.
Sign of the Times:
This sign along Route 160 on the Navajo reservation
near Tuba City, AZ, preaches diabetes prevention. American Indians
who live in the region have an exceptionally high rate of type 2
diabetes. Scientists now find minority youth are also vulnerable
to type 2 diabetes. |
Risk Factors
Four primary factors place youth at risk for type 2 diabetes in
childhood. The first is ancestry: African American, Alaska Native,
American Indian, Asian and Pacific Islander American, and Hispanic
American. Some minority groups may be at greater risk than others;
research is in its early stages.
Obesity seems to be the second important risk factor, especially
among people who carry their fat around the middle and are "superobese."
An Arkansas group of 8- to 12-year-old African-American children
with type 2 diabetes illustrates the problem. More than 85 percent
of the children had a body mass index (BMI), which is equal to a
person's body weight in kilograms divided by height in meters squared,
of 25 or higher; 16 percent were in the "superobese" category.
A study of Japanese children in Tokyo between 1974 and 1994 found
that the prevalence of type 2 diabetes in childhood rose along with
the incidence of obesity and increased fat and animal protein in
the diet. These findings reflect the situation of adults with type
2 diabetes in industrialized nations all over the world.
The third important risk factor is having relatives with type 2
diabetes. According to the report, between 35 and 100 percent of
children with type 2 diabetes in childhood had relatives with diabetes.
Finally, one's sex can provide additional risk. In nearly all groups
studied, significantly more girls than boys got type 2 diabetes
in childhood. The difference, however, varied with the group.
Diagnostic Signs
Faced with a young person who has diabetes, the clinician can no
longer assume the child has type 1. The diagnosis of type 2 diabetes
in childhood can be a complex task requiring the examination of
biochemical characteristics as well as clinical signs.
One important clinical sign for type 2 diabetes in childhood is
acanthosis nigricans (AN), a term used to characterize brownish-black,
velvety skin patches usually found on the back of the neck, in the
armpits, or on the thighs. AN is almost always a sign of high levels
of insulin and, thus, of type 2 diabetes rather than type 1 in childhood.
AN is more common in people of color than in whites and is even
more common among American Indians.
Prevention and Treatment
Because large segments of the population are at risk, clinicians
and researchers advocate aggressive primary prevention and public
health programs to improve people's lifestyles. Some programs have
targeted a variety of interventions in the public schools, community
programs, and homes. The Zuni Diabetes Prevention Program at the
University of Arizona, a program funded by NIDDK, illustrates the
possibilities. Intervention strategies were introduced into parent-teacher
organizations, a new wellness center, school curricula, a teen task
force, and the Indian Health Service. For more than 4 years, participating
Zuni high school students have consumed fewer sugared beverages
and more fiber. As a result, they have lowered their BMI, decreased
their resting pulse rates (usually associated with exercise programs),
and improved their glucose-to-insulin ratios.
In the model programs, youth with type 2 diabetes in childhood
have been treated with oral diabetes medications, a healthy eating
plan, and exercise. A few patients were reported to require insulin
treatment.
In addition, the National Diabetes Education Program has convened
a work group on children and diabetes. The group will examine the
scope and magnitude of the problem and develop messages for health
care providers to increase awareness of type 2 diabetes in youth.
Diagnosing Type 2 Diabetes
in Childhood
Health professionals should suspect type 2 diabetes
in childhood in patients who
- Are of African American, Alaska Native, American
Indian, Asian and Pacific Islander American, and
Hispanic American descent.
- Are between 6 and 9.
- Are female.
- Have centrally distributed body fat ("apple-shaped"
body).
- Have not had a recent weight loss.
- Have no acute symptoms of hyperglycemia.
- Have a family history of type 2 diabetes.
- Have acanthosis nigricans.
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Future Research
The phenomenon of type 2 diabetes in childhood has raised a number
of critical questions for researchers to explore:
- Are there differences in the prevalence of type 2 diabetes in
childhood among different minority populations?
- What are the real costs of obesity to individuals and society?
- How do we distinguish among the natural histories of type 2
diabetes in childhood and atypical diabetes mellitus (ADM), maturity-onset
diabetes of youth (MODY), and type 1 diabetes?
- How much of the type-2-diabetes-in-childhood phenomenon is genetic
and how much is environmental?
- Can type 2 diabetes in childhood be prevented or controlled?
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