[Diabetes mellitus and dementia].

Diabetes mellitus (DM) has been proposed as a risk factors for the development of vascular dementia (VaD) and Alzheimer's disease (AD). We characterized a new clinical entity of a dementia subgroup associated with specific DM-related factors rather than with AD pathology or vascular disease. This type of dementia, not showing hypoperfusion in the parietotemporal lobe on SPECT or cerebrovascular lesions on MRI, was characterized by old age, high hemoglobin A1c level, long duration of diabetes, high frequency of insulin therapy, low frequency of apolipoprotein E 4 carrier, less severe medial temporal lobe atrophy, impaired attention, less impaired word recall, and slow progression of cognitive impairment, all of which differed from the characteristics of AD, and may be referred to as "diabetes-related dementia." In addition to insulin resistance, elevated inflammatory cytokines and oxidative stress were associated with cognitive impairment in this type of dementia. Characterization of a novel entity of diabetes-related dementia may have diagnostic and therapeutic implications.