Blood Pressure Variability and Cognitive Function in the Elderly

With the increase in the aging population, it is important to understand the individual diseases and their interactions which are prevalent and have a great impact on the health status of the elderly. Hypertension is one of the most common diseases in older age and may impact the health status because it is the main risk factor for cardiovascular and cerebrovascular diseases such as heart failure and stroke. Recently, much evidence has been accumulated showing that hypertension plays an important role in the development and progression of cognitive impairment and dementia. Cerebral hypoperfusion secondary to severe atherosclerosis resulting from long-standing hypertension may be a major biological pathway linking high blood pressure (BP) to cognitive decline and dementia. Furthermore, increased BP variability has also been reported to be significantly associated with white matter hyperintensities and brain atrophy, which are predisposing conditions of dementia, depression, and falls in the elderly even after adjusting for BP levels and other confounding variables. Several mechanisms have been shown to be involved in the association between BP variability and cognitive impairment in elderly individuals. In addition to an increased cerebral blood flow fluctuation, neurohumoral activation, endothelial dysfunction, inflammation, and oxidative stress have been suggested to be the underlying mechanisms. However, clinical trials provide limited evidence for a protective effect of antihypertensive therapy against dementia and stroke-related cognitive decline. In this article, we aimed to review the existing evidence of the connection between BP variability and cognitive impairment in elderly people.