Use of the Japanese Version of the Montreal Cognitive Assessment to Estimate Cognitive Decline in Patients Aged 75 Years or Older with and without Type 2 Diabetes Mellitus

Abstract

Background: The number of people diagnosed with dementia worldwide is set to increase significantly. Patients with dementia often have comorbidities, particularly diabetes, and patients with type 2 diabetes mellitus (T2DM) have a high risk of cognitive decline. This study investigated whether older people with T2DM have disease-specific cognitive deficits. Methods: The Montreal Cognitive Assessment is a well-known tool for examining mild cognitive im-pairment, and the modified Japanese version (MoCA-J) has been confirmed as effective. Using the MoCA-J, we assessed the cognitive function of Japanese adults aged ≥75 years with and without T2DM and analyzed the results. Results: Thirty-three patients with T2DM and 23 non-DM patients completed the examination, and MoCA-J total scores differed between these groups (T2DM mean, 21.4 ± 3.5; non-DM mean, 23.5 ± 3.6). Only 9% of patients with T2DM and 39% of those with non-DM had scores ≥26, which is the cutoff point for mild cognitive impairment, although all patients were capable of self-care. Additionally, delayed recall scores were significantly lower for the older patients with T2DM had for the non-DM group. Conclusions: Patients aged ≥75 years with T2DM might have worse cognition than those without T2 DM; the inability to perform delayed recall in T2DM patients suggests a decline in cognitive function. Therefore, patients aged ≥75 years with T2DM should receive explanations of their care that are indi-vidualized in relation to their cognitive status. (J Nippon Med Sch 2022; 89: 196―202).