Demonstrating the case that AD is a vascular disease: epidemiologic evidence

Alzheimerʹs disease (AD) is the most frequent type of dementia in old age. The pathology of AD is not well understood. One hypothesis states that AD has a vascular basis. This hypothesis is controversial because AD has traditionally been studied and treated as a separate disease from vascular dementia. This article reviews the epidemiologic evidence supporting an association between AD and two major vascular risk factors—blood pressure and diabetes. Both methodologic and biologic explanations for these associations are discussed.