Diabetes tied to increased risk for dementia

(CBS) Got diabetes? New research from Japan suggests that your risk of developing Alzheimer's or another form of dementia is greatly elevated.

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For a study published in the Sept. 20 issue of "Neurology," scientists monitored 1,017 men and women age 60 and older for an average of 11 years. The scientists found that those who had diabetes at the start of the study were roughly twice as likely as non-diabetics to develop dementia. Of the 150 people with diabetes, 41 developed dementia. Only 115 of the 559 non-diabetics developed dementia.

The risk of developing dementia was also heightened in people who had "pre-diabetes," a condition marked by slightly elevated levels of blood sugar (glucose). And theheightened risk was evident even when the scientists controlled for high blood pressure, high cholesterol, smoking, and other risk factors for diabetes.

What does it all mean?

"Our findings emphasize the need to consider diabetes as a potential risk factor for dementia," study author Dr. Yutaka Kiyohara, of Kyushu University in Fukuoka, Japan, said in a written statement.

It wasn't the first time scientists had linked diabetes and dementia. But Heather Snyder, senior associate director of medical scientific relations at the Alzheimer's Association, told HealthDay that the study was important because of the large number of subjects and because of its long duration.

Why might diabetes set the stage for dementia? One explanation is that diabetes is known to increase the risk for stroke, which can lead to dementia. But Dr. Zoe Arvanitakis, a neurologist at Rush University Medical Center in Chicago, told WebMD, "The mechanism linking diabetes and dementia still needs to be sorted out."

In the meantime, Dr. Arvanitakis said, the study is another reminder to take steps to reduce the risk for diabetes - and for people who already have diabetes, to get their blood sugar under control.

Risk of diabetes can be reduced by losing excess weight, getting regular exercise, and controlling high cholesterol, high blood pressure, and high triglycerides, according to the American Diabetes Association.

The Alzheimer's Association has more on Alzheimer's disease.