The relationship between insulin resistance and neurodegenerative disease is tantalizing in its potential to offer an integrated architecture for aging of the body and the brain. While there are contradictory findings in this area, the prevalence of insulin resistance is reportedly increased in many age-related neurodegenerative disorders, including Alzheimer disease, vascular dementia, and Parkinson disease.1 Insulin resistance may contribute to the expression of these disorders through shared as well as distinct mechanisms. Identification of these mechanisms could aid the development of effective preventative and therapeutic strategies.