Insulin resistance and cognitive dysfunction.

Epidemiologic and biologic studies support a link between type 2 diabetes mellitus and Alzheimer's disease, but the precise mechanism linking the two remains unclear. Growing evidence supports the concept that insulin resistance is important in the pathogenesis of cognitive impairment and neurodegeneration. Insulin plays a profound role in cognitive function. Impaired insulin signaling in the advancement of cognitive dysfunction is relevant to the pathophysiologic mechanisms of cognitive impairment. In this paper we discuss the relationship between insulin resistance and cognitive impairment and review potential mechanisms of this disease process. Evidence, to date, suggests that brain insulin resistance is an independent risk factor for cognitive impairment.