Type 2 diabetes mellitus, dyslipidemia, and Alzheimer's disease.

The prevalence of Alzheimer's disease (AD) is increasing rapidly, heightening the importance of finding effective preventive therapies for this devastating disease. Midlife vascular risk factors, including type 2 diabetes mellitus (T2DM), have been associated with increased risk of AD decades later and may serve as targets for AD prevention. Studies to date suggest that T2DM and hyperinsulinemia increase risk for AD, possibly through their effects on amyloid-beta metabolism and cerebrovascular dysfunction - two early findings in preclinical AD pathology. This paper reviews the evidence supporting a relationship between T2DM, hyperinsulinemia, and diabetic dyslipidemia on the development of AD, discusses DM treatment trials and their preliminary results on cognitive function, and proposes some strategies for optimizing future AD prevention trial design.