July 17, 2006 (USA TODAY) -- 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.
Copyright 2006 USA TODAY, a division of Gannett Co. Inc.
