Effect of alcohol and tobacco use on vascular dementia: a matched case control study

BACKGROUND Vascular dementia is the second most common type of dementia in the United States. The underlying association of tobacco and alcohol with vascular dementia is not completely understood. PURPOSE Determine the relationship of tobacco and alcohol use with the development of vascular dementia (VaD). METHODS This was a matched case-control study of subjects living in Olmsted County, MN. Cases of VaD were identified through medical record abstraction using conventionally accepted definitions of VaD, using the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Ensignement en Neurosicences ( NINDS-AIRENS) criteria and were matched to controls by gender and age within 3 years among persons free of dementia on the index date. Exposure data for alcohol and tobacco use were abstracted by trained nurses, along with demographic, lifestyle, cerebrovascular, cardiovascular, and vascular comorbid disease characteristics. Matched conditional logistic regression for univariate and multivariate evaluation of the association of tobacco and alcohol use with VaD was utilized. RESULTS Current alcohol exposure was associated with a decreased risk of VaD with an odds ratio of 0.48 (95% confidence interval: 0.31-0.74). This protective effect of alcohol was seen in men, women, and subjects under 80 years of age. Tobacco use was not associated with VaD in univariate and multivariate analysis, and stratified analysis did not reveal any subgroup-specific associations between tobacco use and VaD in the study population. CONCLUSION Current alcohol use appears to have protective effects against the development of vascular dementia. The effects are more pronounced in subjects under age 80. This may reflect the direct vascular effects of alcohol on the vascular system or may represent a surrogate for better social or functional status. Previous alcohol use was not protective. Tobacco use was not a risk factor for VaD status, which was possibly an indication of survivorship bias in the cohort.