Vascular health, diabetes, APOE and dementia: the Aging, Demographics, and Memory Study

A population-based sample of 856 individuals aged 71 years or older from all contiguous regions of the United States received an extensive in-home clinical and neuropsychological assessment in 2001-2003. The relation of hypertension, diabetes, heart disease, stroke, medication usage, and APOE ε4 to dementia was modelled using adjusted multivariable logistic regression.Treated stroke (odds ratio [OR] 3.8, 95% confidence interval [CI] 2.0, 7.2), untreated stroke (OR 3.5, 95% CI 1.7, 7.3), and APOE ε4 (OR 2.8, 95% CI 1.7, 4.5) all increased the odds of dementia. Treated hypertension was associated with lower odds of dementia (OR 0.5, 95% CI 0.3, 1.0). Diabetes and heart disease were not significantly associated with dementia. A significant interaction was observed between APOE ε4 and stroke (P = 0.001).Data from the first dementia study that is representative of the United States population suggest that stroke, the APOE ε4 allele and their interaction are strongly associated with dementia.Identification of modifiable risk factors for Alzheimer's disease (AD), vascular dementia (VaD), and other dementias could potentially lead to a reduction in the human and economic costs these conditions place on aging populations. Better prevention of vascular disease and better treatment of vascular risk factors, in particular, may hold promise for decreasing the incidence of these debilitating disorders [1,2]. A number of related vascular risk factors and conditions -- for example, hypertension, diabetes, heart disease, and stroke -- have been studied to determine their relation to AD and VaD. However, many of these prior studies have been based on highly selected clinical samples or community-based samples from geographically localized areas, thus raising questions about the generalizability of findings [3].Studies of blood pressure and prevalent dementia have noted an inverse relation in late-life [4], perhaps indicating that the dementia processes itself leads to lower blood pre