For older people with diabetes, the condition does not increase the likelihood that they’ll develop Alzheimer’s disease, according to a report in the medical journal Neurology. However, diabetes is associated with areas of brain damage called cerebral infarction which can impair mental capacity.

Dr. Zoe Arvanitakis from Rush University Medical Center, Chicago, Illinois and colleagues reviewed autopsy results from 233 older participants in the Religious Orders Study.

The team found just over one third of participants had one or more cerebral infarctions, and patients with diabetes were about 2.5 times more likely than others to have cerebral infarction.

In contrast, the levels of Alzheimer-type damage were similar between subjects with and without diabetes.

“This finding is interesting,” Arvanitakis said, “given that several recent large epidemiologic studies have found that diabetes increases risk of clinically-diagnosed Alzheimer’s disease by about two-to-three fold.”

“Diabetes increases risk of dementia, clinically-diagnosed Alzheimer’s disease, and is associated with cognitive impairment and decline in cognition, Arvanitakis pointed out. “Researchers need to better understand mechanisms underlying these relations. This understanding may contribute toward decreasing effects of diabetes on the brain.”

SOURCE: Neurology, December 2006.