Investigation on the relationship between diabetes mellitus type 2 and cognitive impairment

Objective: The incidence of cognitive impairment is increasing with age; however, little is known about the role of hyperglycemia in cognitive impairment. This study focuses on investigating the relationship between diabetes mellitus type 2 and cognitive impairment. Methods: 60 diabetic patients, amongst whom, 30 had a well-controlled diabetes status and the other 30 had not. These patients were compared to 60 non-diabetic controls whose age, sex and educational class matched with the individuals of the first group. Patients with important risk factors for cognitive disorders (renal failure, major depressive disorders and psychoactive drug users, cerebrovascular accident history, etc.) were not included in the study. Modified Mini Mental Status examination (mMMSE) was done for all patients by a blinded expert examiner. Results: Subjects with diabetes (n = 60) had lower MMSE score than those without diabetes (P < .01). Diabetes was also associated with increased odds of cognitive decline as determined by MMSE scores (odds ratio = 1.9; CI = 95%, 1.01-3.6). A significant correlation between duration of disease and cognitive dysfunction was observed, P = 0.001. Also, the same correlation was found for quality of diabetes control, P = 0.002. Conclusion: Diabetes mellitus is associated with lower levels of cognitive function. (c) 2008 Elsevier Ireland Ltd. All rights reserved.