Diabetes: As Vasoregulation Goes Down, So Does Cognitive Function

A recent Beth Israel Deaconess Medical Center (Boston, MA), study shows decreased vasoregulation in the brain leads to increased inflammation and loss of cognitive function in older adults with type 2 diabetes mellitus. The study, by Vera Novak, MD, PhD, and colleagues, was published in the July 8 online edition of Neurology.

Type 2 diabetes has been known to be a risk factor for the development of cognitive decline and dementia. This study investigated the relationship between the disease, decreased blood flow in the brain, and loss of cognitive skills. Sixty-five participants were enrolled in the two-year study, which took place at the Clinical Research Center and the MRI Center at Beth Deaconess Medical Center. Approximately half the participants, or 35, had been treated for type 2 diabetes for at least five years. The other 30 were members of the control group and were not diagnosed with the disease.

Participants underwent the same set of tests twice; the first time at the beginning of the study, to establish a baseline, and the second time two years later. The tests included cognitive function, memory, learning, and activities of daily living measures, as well as MRI and blood tests.

At baseline, participants with diabetes had higher BMI, a greater prevalence of high blood pressure, and lower scores on the cognitive function tests than the control group. At the two-year follow up, the group with diabetes showed significantly more decline than the control group in every measure.

In the group of participants with diabetes blood flow regulation decreased by more than 50% over the two years of the study, and there was a positive correlation between blood flow and worsened performance on the tests measuring cognitive abilities. The control group did not see similar declines.

The researchers “observed that higher levels of inflammatory markers are associated with greater impairment in cerebral vasoregulation and linked altered vasoregulation to faster cognitive decline in older adults with type 2 diabetes.” Understanding the long-term effects of diabetes on the brain may impact how the growing population of older adults with diabetes are cared for and treated.