The prevalence of diagnosed diabetes in U.S. adults age 20 and
older has risen from about 5.1 percent to 6.5 percent, according
to researchers at the National Institutes of Health (NIH) and the
Centers for Disease Control and Prevention (CDC), who analyzed national
survey data from two periods — 1988 to 1994 and 1999 to 2002.
However, the percentage of adults with undiagnosed diabetes did
not change significantly over the years studied. About 2.8 percent
of U.S. adults — one-third of those with diabetes —
still don’t know they have it.
The study, published in the June 2006 issue of Diabetes Care,
notes that type 2 diabetes accounts for up to 95 percent of all
diabetes cases and virtually all undiagnosed diabetes cases. Diabetes
is a group of diseases marked by high levels of blood glucose resulting
from defects in insulin production, insulin action, or both. It
is the most common cause of blindness, kidney failure, and amputations
in adults and a major cause of heart disease and stroke.
Over the years studied, about 26 percent of adults age 20 and older
continued to have impaired fasting glucose (IFG), a form of pre-diabetes.
IFG, in which blood glucose measured after an overnight fast is
high but not yet diagnostic of diabetes, increases the risk of heart
disease as well as the risk of developing type 2 diabetes.
“It’s important to know if you have pre-diabetes or
undiagnosed type 2 diabetes,” said Dr. Larry Blonde, chair
of the National Diabetes Education Program (NDEP), jointly sponsored
by the NIH, CDC, and 200 partner organizations. “You should
talk to your health care professional about your risk. If your blood
glucose is high but not high enough to be diagnosed as diabetes,
losing weight and increasing physical activity will greatly lower
your risk of getting type 2 diabetes. If you have diabetes, controlling
your blood glucose, blood pressure, and cholesterol will prevent
or delay the complications of diabetes.”
The researchers also found that:
- nearly 22 percent of people age 65 and older had diabetes.
- about 13 percent of non-Hispanic blacks age 20 and older had
diabetes. Diabetes was twice as common in non-Hispanic blacks
compared to non-Hispanic whites.
- about 8 percent of Mexican Americans age 20 and older had diabetes.
Because the average age of Mexican Americans is younger than for
other groups, the age-and sex-adjusted prevalence of diabetes
in Mexican Americans is twice that of non-Hispanic whites and
about equal to that of non-Hispanic blacks.
- IFG and undiagnosed diabetes were about 70 percent more common
in men than in women, especially in non-Hispanic white men.
- nearly 40 percent of people age 65 and older had IFG, which
becomes more common with age.