Despite numerous reports that have linked diabetes with cognitive impairment (CI), there are few studies that have attempted to clarify the morbidity of CI among elderly diabetic patients. The Mini-Mental State Examination (MMSE) was performed on 240 diabetic patients aged 65 years or older who had no diagnosis of dementia. The MMSE scores were 28-30 (normal range) in 151 patients (63%), 24-27 (suspected CI) in 77 (32%), and ≤ 23 (definite CI) in 12 (5%). Eight of the 12 patients with MMSE scores ≤ 23 underwent further detailed examination: the final diagnosis was Alzheimer’s disease (AD) (N = 5), vascular dementia (N = 2), and mixed dementia (N = 1). Among 24 of the 77 patients with MMSE scores of 24-27 who were referred for further detailed examination, the final diagnosis was early AD (N = 5), cerebrovascular disease (CVD) (N = 10), and mild CI (N = 7). Only 2 of the patients were judged as being normal. The percentage of patients with a history of CVD, the rate of diuretic use, and the serum levels of non-high-density lipoprotein cholesterol were higher, and the percentage of patients with a history of habitual alcohol consumption was lower in the low MMSE score group than in the normal MMSE score group. Among elderly diabetic patients aged 65 years or older, 5% had evident CI and 32% had suspected CI. Medical staff involved in the care of diabetic patients should be highly aware of possible CI in this patient population.
The Japan Endocrine Society