Increased detection of mild cognitive impairment with type 2 diabetes mellitus using the Japanese version of the Montreal Cognitive Assessment: A pilot study

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Studies show that diabetes mellitus is the greatest lifestyle risk factor for dementia. Appropriate management and treatment of type 2 diabetes mellitus could prevent the onset and progression of mild cognitive impairment to dementia.</jats:p></jats:sec><jats:sec><jats:title>Aim</jats:title><jats:p>Detection of mild cognitive impairment in patients with type 2 diabetes mellitus.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Mild cognitive impairment was assessed using the Japanese version of the Montreal Cognitive Assessment. The study population was 33 non‐demented inpatients with type 2 diabetes mellitus receiving diabetes management training. The Japanese version of the Montreal Cognitive Assessment, the animal naming test and the digit‐symbol coding subtest of the Wechsler Adult Intelligence Scale were administrated in one‐to‐one interviews.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The prevalence of mild cognitive impairment in diabetic patients was 72%. The background characteristics of mild cognitive impairment in diabetic patients included fewer schooling years and higher glycated hemoglobin levels in comparison to subjects without mild cognitive impairment. Neuropsychological testing showed that diabetic patients with mild cognitive impairment scored lower on the Japanese version of the Montreal Cognitive Assessment (total score, <jats:italic>P</jats:italic> < 0.0001), frontal lobe function (<jats:italic>P</jats:italic> < 0.001) and delayed recall (<jats:italic>P</jats:italic> < 0.05). The number of correct answers on the digit‐symbol coding subtest was also significantly lower in diabetic patients with mild cognitive impairment (<jats:italic>P</jats:italic> < 0.05).</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Mild cognitive impairment with type 2 diabetes mellitus has a high prevalence. Our study suggests that mild cognitive impairment in diabetic patients can be classified into three groups: predominantly frontal lobe dysfunction, predominantly delayed recall impairment and a mixed‐type group.</jats:p></jats:sec>