Is Diabetes Making Brains Smaller?

Type 2 diabetes linked to smaller brain volume and larger ischemic lesions

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) While the size of your head may not matter so much, the size of your brain does. If parts of your brain get smaller, you may be faced with brain function problems. Diabetes may play a role in this process.

Type 2 diabetes may be associated with smaller brain volumes in parts of the brain involved in memory, speech and other functions.

"Control you diabetes to prevent complications."

Past research has linked diabetes to problems with cognitive function, or the ability of the brain to do tasks that involve memory, language and problem solving. Changes to brain tissues also may affect these functions.

Mark A. Espeland, PhD, of Wake Forest School of Medicine in North Carolina, and colleagues wanted to see if type 2 diabetes led to changes in brain volume and cognitive function.

The researchers used magnetic resonance imaging (MRI) to measure brain volumes and ischemic lesions (changes to the brain tissue) in 1,366 women between 72 and 89 years of age. After an average of 4.7 years, 698 of those women had a second MRI scan.

After the first scan, 145 women with diabetes (10.6 percent) had smaller total brain volumes and smaller gray matter volumes than those without diabetes.

Gray matter includes parts of the brain involved in memory, muscle control, seeing, hearing and speech.

The researchers found that the 145 women with diabetes had total brain volumes that were 0.6 percent smaller and gray matter volumes that were 1.5 percent smaller than those without diabetes.

Volumes of white matter (brain tissue that messages pass through) were not different between those with and without diabetes.

In addition, women with diabetes had bigger ischemic lesions than those without diabetes.

These ischemic lesions were bigger overall, only in gray matter, only in white matter and across major sections of the brain.

More specifically, ischemic lesions were 21.8 percent larger in people with diabetes compared to those without the condition.

In gray matter, ischemic lesions were 27.5 percent larger among diabetes patients. In white matter, the lesions were 18.8 percent larger among those with diabetes.

Over the course of the study, women with diabetes lost slightly more brain volume than those without diabetes. However, the difference in loss was not significant.

Compared to those without diabetes, women with diabetes had a 9.7 percent greater increase in the size of ischemic lesions.

In addition, the researchers found that diabetes was associated with lower cognitive function. That is, women with diabetes may be more likely to have problems with memory, speech and other thinking processes.

The authors concluded that these brain volume losses and lesions may play a role in brain function problems among people with diabetes. However, these changes do not fully explain why people with diabetes may have a higher risk of brain function problems, they said.

The study was published August 29 in Diabetes Care, a journal of the American Diabetes Association.

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Review Date: 
September 6, 2012
Last Updated:
September 10, 2012