Global cognition and executive functions of older adults with type 1 diabetes mellitus without dementia

Aims/Introduction: This study aimed to characterize the global cognition and executive functions of older adults with type 1 diabetes mellitus in comparison with type 2 diabetes mellitus. Materials and Methods: This study included 37 patients with type 1 diabetes mellitus aged >= 65 years and 37 age- and sex-matched patients with type 2 diabetes mellitus. Patients with dementia scoring <24 on the Mini-Mental State Examination were excluded. General cognition, memory, classic, and practical executive function were investigated. Results: Patients with type 1 diabetes mellitus demonstrated lower psychomotor speed scores on Trail Making Tests A and B (P < 0.001, P < 0.013) than those with type 2 diabetes mellitus. The dysexecutive syndrome behavioral assessment revealed similar results in patients with types 1 and 2 diabetes mellitus. The Wechsler Memory Scale-Revised verbal episodic memory and Montreal Cognitive Assessment Japanese version were similar in terms of general cognition, but worse delayed recall subset on the latter was associated with type 2 diabetes mellitus (P = 0.038). A worse Trail Making Test-A performance was associated with type 1 diabetes mellitus and age (P < 0.004, P < 0.029). Conclusions: Executive function of psychomotor speed was worse in older outpatient adults without dementia with type 1 diabetes mellitus than in those with type 2 diabetes mellitus but with no significant differences in the comprehensive and practical behavioral assessment of dysexecutive syndrome. Patients with type 1 diabetes had more severely impaired executive function, whereas those with type 2 had greater impaired memory than executive function.