Cognitive impairment in elderly patients with type 2 diabetes mellitus: prevalence and related clinical factors.

Aim: Diabetes mellitus is reported to be a risk factor for dementia. We evaluated the cognitive function in elderly diabetic patients and estimated the prevalence of patients with cognitive impairment and looked for any related clinical factors.

Subjects And Methods: Using 281 elderly (65 years of age or older) Japanese patients with type 2 diabetes mellitus who were free of clinically evident cognitive impairment, we evaluated their cognitive function with the Mini Mental State Examination (MMSE).

Results: The MMSE score of all the participants was 27.3 ± 2.4 with 31.3% of them being in the abnormal range (tentatively defined normal range as having an MMSE score of 27-30). Multiple regression analysis disclosed that fasting serum non-esterified fatty acid (NEFA), estimated glomerular filtration ratio (eGFR) and insulin treatment were significantly related factors for the MMSE score, in addition to age and schooling history, which are extremely strong factors.

Conclusions: We revealed that approximately one-third of elderly type 2 diabetic patients who were free of clinically evident cognitive impairment had impaired cognitive function, demonstrating that the MMSE score was significantly correlated with fasting NEFA level, renal function, insulin treatment, age and schooling history.