Results of a recent study conducted by researchers at Wake Forest University Baptist Medical Center and colleagues show that cognitive functioning abilities drop as average blood sugar levels rise in people with type 2 diabetes.

The study appears in this month's issue of Diabetes Care.

The ongoing Memory in Diabetes (MIND) study, a sub-study of the Action to Control Cardiovascular Risk in Diabetes Trial (ACCORD), found a statistically significant inverse relationship between A1C levels (average blood glucose levels over a period of two to three months) and subjects' scores on four cognitive tests. No association, however, was found between daily blood glucose levels (measured by the fasting plasma glucose test) and test scores.

For the study, researchers at 52 of the 77 ACCORD sites throughout the United States and Canada administered a 30-minute battery of cognitive tests to nearly 3,000 individuals ages 55 years and older.

"The tests used in the study measured several aspects of memory function," said Jeff Williamson, M.D., M.H.S., principal investigator for the study at the Wake Forest clinical site. "For example, we tested one's ability to switch back and forth between memory tasks or to 'multitask,' an important skill for people needing to manage their diabetes."

The results showed that a 1 percent increase in A1C corresponded to slightly lower scores on tests of psychomotor speed, global cognitive function, memory and multiple task management…