According to a new study people with type 2 diabetes who have higher average blood glucose (sugar) levels may have lowered cognitive functioning. The study published online today in the journal Diabetes Care reported that patients who had higher levels of hemoglobin A1C showed significantly worse performance at cognitive tasks which require memory, speed and the ability to manage multiple tasks at the same time.

A1C levels are a measure of the average blood glucose levels over a 2-3 month period. Higher A1C levels were also linked to a lower score on tests of global cognitive functioning. The study called the Memory in Diabetes (MIND) study was a sub study of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. 

Studies conducted earlier have shown that people with diabetes are 1.5 times more likely to experience cognitive decline and symptoms of dementia as compared to people who do not have the disease. The MIND results now link diabetes with mild cognitive impairment. 

Lead researcher Dr. Tali Cukierman-Yaffe, of the Gertner Institute for Epidemiology & Health Policy Research, Endocrinology Institute at Sheba Medical Center & Sackler School of Medicine at Tel-Aviv University in Israel in an American Diabetes Association news release said, "Even a mild impairment in cognitive function is of concern for people with type 2 diabetes."

The researchers however said as the results were cross sectional it is not clear if the higher blood sugar levels increases the risk for cognitive impairment or whether cognitive impairment decreases the body's ability to control the blood sugar levels. They are hoping this question will be answered in the ongoing ACCORD-MIND study being conducted in the hope of finding out if by lowering A1C levels cognitive function can improve.  In this study patients are followed over time and tested three times during the trial period. 

The ACCORD-MIND study was funded by the National Institute on Aging, in collaboration with the ACCORD trial funded by the National Heart, Lung, and Blood Institute (NHLBI). Additional support came from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the National Eye Institute, and the Centers for Disease Control and Prevention. (Harkiran Contributed to this report)