Story highlights Type 2 diabetics who were overweight had more severe abnormalities in brain structure, study says

The effects were judged against normal-weight diabetics

(CNN) It's well-known that type 2 diabetes can cause medical complications in certain organs, including the brain. But overweight and obese people with early-stage type 2 diabetes have more severe abnormalities in brain structure and cognition than normal-weight people with type 2 diabetes, according to a new study in Diabetologia, the journal of the European Association for the Study of Diabetes.

Having type 2 diabetes and being overweight, then, can combine to have a greater effect on brain structures.

"There's a general agreement that type 2 diabetes is a risk factor for various types of both structural and functional abnormalities in the brain," said Dr. Donald C. Simonson, a co-author of the study and an endocrinologist specializing in diabetes. "Simple obesity also shows the same type of abnormalities ... in a milder stage. You can see where it's not quite exactly normal but not quite as bad as someone with diabetes.

"So, if you have both, will it be worse than if you have them alone? That's what we looked at in this particular study," said Simonson, who teaches at Harvard's T.H. Chan School of Public Health.

Dr. In Kyoon Lyoo, lead author and a professor at the Ewha Brain Institute at Ewha Womens University in Seoul, South Korea, wrote in an email, "As obesity has been known to be associated with metabolic dysfunction, inflammation, and brain changes independently of diabetes, we expected that brain alterations might be more pronounced in overweight/obese participants with type 2 diabetes."

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