Stroke History Raises Risk of Vascular Dementia

PORTO, PORTUGAL – Stroke was associated with a nearly 20-fold increase in risk for vascular dementia in a univariate, retrospective, case-control analysis presented at the Fourth International Congress on Vascular Dementia.

Among 205 people with vascular dementia and their control cases, those with a history of stroke were 19 times more likely to develop vascular dementia in the univariate analysis, said Dr. Casey R. Caldwell, an internal medicine physician at the Mayo Clinic, Rochester, Minn. The association of dementia with stroke was stronger in men, who had an odds ratio of 28, than in women, who had an odds ratio of 16.

For the analysis, all Mayo Clinic health records from residents of Olmsted County, Minnesota, during the period 1994–2002 were screened for any of 40 diagnoses suggestive of dementia. This screening identified 1,736 potential subjects, among whom 205 cases of vascular dementia were identified using criteria from the National Institute of Neurological Disorders and Stroke and from the Association Internationale pour la Recherché et l'Enseignement en Neurosciences (NINDS-AIREN).

The subjects were age- and gender-matched with community controls. Individuals were excluded as possible community control subjects if they had been diagnosed with dementia of any kind. Medical records were retrospectively evaluated for the pair from the date of vascular dementia diagnosis. The researchers assessed participant demographics and each subject's history of smoking, alcohol abuse, obesity, diabetes, stroke or transient ischemic attack, hypertension, coronary artery disease, heart failure, myocardial infarction, peripheral vascular disease, angina, pulmonary embolism/deep vein thrombosis, and other factors.

The researchers used univariate and multivariate conditional logistic regression to estimate the odds ratio for vascular dementia associated with exposure to specific risk factors and to explore interactions among the different risk factors.

In the univariate analysis, stroke, transient ischemic attack, diabetes, peripheral vascular disease, hypertension, and coronary artery disease were associated with an increased risk of vascular dementia.

In the multivariate analysis, stroke history, atrial fibrillation, and diabetes were associated with an increased risk of vascular dementia. Hypertension approached statistical significance in this model.