Arterial stiffness and cognitive impairment in the elderly

Older patients present two major challenges to clinicians and researchers in the hypertension and cardiovascular field: the first is represented by the need to focus not only on 'hard' cardiovascular events (myocardial infarction, stroke, congestive heart failure) but also on functional disability; the second is to better understand and to account for the interaction between the aging process and elevated blood pressure. Cognitive decline is a major burden for public health and it is emphasised by the progressive aging of populations worldwide. Vascular factors have been progressively recognised as playing a critical role in cognitive decline with aging. Aging affects not only cognitive function but also the vascular system. Stiffening of large arteries is one of the prominent and typical features of aging and is more remarkable in proximal elastic arteries than in the peripheral muscular arteries. We propose that large artery stiffness is a prominent link between aging and cognitive decline. Indeed, increased arterial stiffness implies that flow pulsation created by left ventricular contraction cannot be adequately cushioned in the arterial system. Since the brain has a high resting flow, implying that vessels are more dilated than in other vascular beds, pulsations may extend more deeply towards the smallest cerebral vessels, causing not only cerebral damage secondary to increased risk of stroke but also microvascular brain damage. We recently demonstrated cross-sectionally that arterial stiffness, measured noninvasively as pulse wave velocity (PWV), was associated with lower cognitive performance independently of traditional cardiovascular risk factors and independently of neurodegenerative or microvascular damage on neuroimaging (CT scan) in older individuals without prior stroke and free of atrial fibrillation. We extended the reported cross-sectional observations with a longitudinal study showing that PWV not only predicted cognitive decline independently of age, sex, education and traditional cardiovascular risk factors, but was also the single strongest predictor of cognitive decline. In conclusion, certain noninvasive measures of large artery stiffness, such as carotid-femoral PWV, may be used as clinical markers for predicting cognitive decline in older persons. Additionally, these measures can be adopted for monitoring pharmacological responses to a therapeutic intervention aimed at slowing cognitive deterioration in patients with memory loss. Future studies are required to evaluate whether interventions that reduce arterial stiffness are likely to improve the small as well as large arteries of vital organs and thereby delay, prevent or improve cerebral dysfunction in the elderly. © 2007 Adis Data Information BV. All rights reserved.