Children who get obesity-related diabetes face a much higher risk of kidney
failure and death by middle age than people who develop diabetes as adults, a
study suggests.
The study offers some of the first strong evidence of the consequences of the
nation's growing epidemic of type 2 diabetes in children, said Dr. William
Knowler, a co-author and researcher with the National Institute of Diabetes and
Digestive and Kidney Diseases.
The research also lends support to warnings that diabetes and other
obesity-related ills are on the verge of shortening average life span in the
United States.
The study involved Pima Indians in Arizona, who have disproportionately high
rates of diabetes and obesity. They may be "the tip of the iceberg, letting us
know what's in the future for the rest of America if we don't do something about
the childhood obesity epidemic," said Dr. David Ludwig, director of Children's
Hospital Boston's obesity program. He was not involved in the research.
The study appears in Wednesday's Journal of the American Medical Association.
It involved a group of Indians whom National Institutes of Health researchers
have been tracking since 1965. Of the 1,865 participants with Type 2 diabetes,
96 developed it in childhood. The average age of youth-onset diabetes was about
17 years, although the disease was diagnosed in children as young as 3 1/2.
During at least 15 years of follow-up, 15, or 16 percent, of those with
childhood-onset type 2 diabetes developed end-stage kidney failure or died from
diabetic kidney disease by age 55. That compared with 133, or 8 percent, of
those who developed diabetes after age 20.
The researchers calculated that the incidence of end-stage kidney failure and
death by age 55 was nearly five times higher in people who developed type 2
diabetes before age 20 than in those who developed diabetes in adulthood.
Most of the 20 million Americans with diabetes are adults with type 2. While
a generation ago, type 2 diabetes was almost unheard of in children, the
incidence has increased substantially in the past decade, largely because of
obesity and lack of exercise.
Diabetes impairs the body's ability to regulate blood sugar levels. That can
lead to damage to the kidneys and blood vessels throughout the body.
When type 2 diabetes develops earlier in life, it has many more years to
cause damage and can lead to premature complications and death, the researchers
said.
The American Diabetes' Association's Dr. Larry Deeb said that may not be the
only explanation. During adolescence, kidneys are still maturing and may be
particularly vulnerable to diabetes' effects, said Deeb, a pediatrics professor
at the University of Florida.
While Pima Indians are among ethnic groups believed to have a genetic
predisposition toward diabetes and obesity, the researchers said the results
probably apply to others as well.
And even in people with a genetic predisposition, weight control and physical
activity can help delay the onset of type 2 diabetes.
A recent study by pharmacy benefits manager Express Scripts Inc. found that
prescriptions for type 2 diabetes drugs doubled among U.S. children ages 5 to 19
from 2002 to 2005.
