We appreciate the comments of Hayden and colleagues supporting the conclusions of our recent article on stroke and the risk of AD.1 Their data from the Cache County Study2 do show an apparently similar effect, even if not meeting statistical significance, of stroke history on the incidence of AD. The larger proportion of individuals with stroke in our cohort likely reflects a higher frequency of stroke-related risk factors in our population, as do the differing small age discrepancies between subjects with and without stroke (those with stroke were 1 year younger than those without stroke in the Washington Heights-Inwood Columbia Aging Project1 but 2 years older in the Cache County Study2). Probably the proportion of cases of incident dementia was larger in the Washington Heights-Inwood Columbia Aging Project simply because of the longer follow-up (approximately 7 years vs about 3 years). We agree entirely on the need for further research investigating the mechanisms by which stroke might increase the risk of AD.
Honig LS, Mayeux R. Self- or Proxy-Reported Stroke and the Risk of Alzheimer Disease—Reply. Arch Neurol. 2004;61(6):983. doi:10.1001/archneur.61.6.983-a