[Diabetes Mellitus and Dementia]

Accumulating data have established that diabetes mellitus (DM) is a risk factor for dementia of both Alzheimer's and vascular types. However, the underlying mechanism of DM-induced neurodegeneration remains to be fully elucidated. Insulin resistance (IR) in the brain may be involved in DM-related cognitive impairment or dementia, and treatment of IR in the brain may lead to the prevention and/or treatment of dementia. Although glucose lowering therapy is expected to prevent the development and progression of cognitive decline in older DM patients, limited clinical data are available thus far. Research efforts should be continued in this field. DM patients with dementia have difficulties in maintaining their anti-diabetic treatment. Because these patients are often frail, and have renal dysfunction, and poor adherence to treatment, they are at high risk of developing hypoglycemia, which in turn may induce cognitive dysfunction. We should all keep in mind that older diabetic patients are at a high risk of dementia and should provide comprehensive and careful medical treatment for these patients.