Type 2 Diabetes May Shrink the Brain
Loss of gray matter can lead to dementia, experts say
By Steven Reinberg
TUESDAY, April 29, 2014 (HealthDay News) -- People with type 2 diabetes may lose more brain volume than is expected as they age, new research indicates.
Surprisingly, this shrinkage doesn't appear to be linked to the damaging effect of diabetes on tiny blood vessels in the brain, but instead by how the brain handles excess sugar, the researchers noted.
"We have known for a long time that diabetes is not good for the brain," said lead researcher Dr. R. Nick Bryan, a professor of radiology at the University of Pennsylvania's Perleman School of Medicine in Philadelphia.
Diabetes is associated with an increased risk for stroke and dementia, he said. Until now, doctors have thought these risks were likely related to blood vessel damage related to diabetes.
"But our study suggests that there is additional damage to the brain which may be more like a brain disorder such as Alzheimer's disease," Bryan said. "So there may be two ways diabetes affects the brain, damage to blood vessels and brain-cell degeneration."
The brain shrinkage seen in this study may be linked with how sugar is used by the brain, Bryan said.
"It is important that patients understand the adverse effect of their disease on their brains and cooperate with their doctors who are trying to treat their diabetes and prevent the effects of diabetes on the brain and other organs," he said.
Bryan cautioned, however, that what isn't known from this study is if treating diabetes will prevent or slow brain shrinkage.
Nearly 26 million people in the United States have diabetes, according to the American Diabetes Association. In type 2 diabetes, the body often doesn't use insulin efficiently, leading to an excess of both insulin and blood sugar, according to the association.
For the study, Bryan and his colleagues used MRI scans to look at the brains of 614 people with type 2 diabetes. The volunteers had diabetes for an average of about 10 years.
They found that the longer a patient had the disease, the more brain volume loss occurred, particularly in the gray matter. Gray matter includes areas of the brain involved in muscle control, seeing and hearing, memory, emotions, speech, decision-making and self-control.