Many complications of diabetes, including kidney disease, foot problems and vision problems are generally well recognized. But the disease's impact on the brain is often overlooked.

In a study published in the November 2011 issue of the journal Diabetes Care, Beth Israel Deaconess Medical Center (BIDMC) neurophysiologist Vera Novak, MD, PhD,  report that in older patients with diabetes, two adhesion molecules – sVCAM and sICAM – cause inflammation in the brain, triggering a series of events that affect blood vessels and, eventually, cause brain tissue to atrophy. Importantly, the team found that the gray matter in the brain's frontal and temporal regions -- responsible decision-making, language, verbal memory and complex tasks – is the area most affected by these events."In fact, at the age of 65, the average person's brain shrinks about one percent a year, but in a diabetic patient, brain volume can be lowered by as much as 15 percent."

Novak's team recruited 147 study subjects, averaging 65 years of age. Seventy one of the subjects had type 2diabetes and had been taking medication to manage their conditions for at least five years. The other 76 were age and sex-matched non-diabetic controls.

"It appears that chronic hyperglycemia and insulin resistance – the hallmarks of diabetes – trigger the release of adhesion molecules [sVCAM and sICAM] and set off a cascade of events leading to the development of chronic inflammation," says Novak.

This discovery now provides two biomarkers of altered vascular reactivity in the brain. "If these markers can be identified before the brain is damaged, we can take steps to try and intervene," says Novak, explaining that some data indicates that medications may improve vascoreactivity.