A "silent" condition called
prediabetes might put otherwise healthy seniors at
risk of developing Alzheimer's disease, a study suggests
today.
Researchers will present findings
from that study, and several others, at the 10th International
Conference on Alzheimer's Disease and Related Disorders
this week in Madrid. The new findings bolster the
theory that diabetes or even a precursor condition
might somehow set the stage for Alzheimer's disease,
says Ronald Petersen, a spokesman for the Alzheimer's
Association, which sponsored the meeting.
If true, that theory has sobering
implications for the USA, which is in the midst of
a diabetes epidemic. Roughly 61 million American adults
have diabetes, or higher-than-normal blood-sugar levels.
Previous research had established
a link between type 2 diabetes and a greater chance
of Alzheimer's. But today's study by Weili Xu and
colleagues at the Karolinska Institute in Stockholm
suggests that the threat begins even before the onset
of full-blown diabetes.
The team studied 1,173 people
age 75 and older. None had dementia or Alzheimer's
at the beginning of the study, but 47 had prediabetes,
a condition in which blood-sugar levels are slightly
higher than normal but usually don't cause any symptoms.
The team kept track of seniors for nine years and
then tested them for Alzheimer's, which causes confusion
and severe memory loss.
They found that people who had
prediabetes at the beginning of the study had a 70%
increased risk of developing dementia, including Alzheimer's.
"I was a little surprised," Xu says, adding that doctors
tend to ignore the slightly high sugar levels until
the levels reach the stage of full-blown diabetes.
Xu says weight loss and exercise
can bring down slightly elevated blood-sugar levels.
People who take those relatively simple steps can
often stave off diabetes, she says. And this research
suggests they'll get a bonus: protection from Alzheimer's.
People who already have developed
type 2 diabetes also can lower their risk, according
to a second study presented at the meeting in Madrid.
Rachel Whitmer of Kaiser Permanente's
Division of Research in Oakland kept track of more
than 22,000 patients with type 2 diabetes and found
that those who kept their blood-sugar levels as close
to normal as possible had the lowest risk of developing
dementia, including Alzheimer's.
People who have type 2 diabetes,
which often develops in adults, can keep sugar levels
in check with exercise, weight control and medication,
she says.
The link between Alzheimer's
and diabetes has yet to be solidified, cautions Murali
Doraiswamy, an Alzheimer's expert at Duke University
in Durham, N.C.
But uncertainty in the science
shouldn't stop people from taking steps to lose weight
— especially if they have creeping blood-sugar
levels.
"I think there are things you
can do to slow down or prevent cognitive loss," Whitmer
says.
