Two indicators of a healthy, reactive vasculature were each associated with lower amyloid burden in the brain (Amyloid is currently believed to be an early marker of Alzheimer’s disease).
- dropping of blood pressure at night compared to BP while awake [measured via ambulatory 24 hr blood pressure monitoring].
- greater cerebrovascular reactivity in response to physical activity [assessed using transcranial doppler of the intracranial middle cerebral artery]
From the green journal Neurology, “the ability of the cerebral vasculature to respond to stimuli (reactivity) is another sign of vascular health.”
Previous studies have shown that lack of ‘nocturnal dipping’ of blood pressure has been associated with:
- greater prevalence of vascular and metabolic risk factors
- higher mortality
- higher prevalence of stroke and other cardiovascular events
- great white matter lesions on brain MRI
- worse performance on cognitive function tests
From the article: “…sustained elevations in blood pressure can impose a substantial mechanical stress on the cerebrovascular beds and subsequently cause vascular remodeling and dysfunction”.
This is yet another study tying blood vessel health to brain decline and Alzheimer Disease. In fact, the authors state “Mounting evidence suggests a link between Alzheimer Disease and the presence of cardiovascular risk factors such as elevated blood pressure”.
Interestingly, an editorial in Neurology accompanying the article mentions that “a more physiologically relevant stimulus to study cerebrovascular reactivity is the change in systemic BP and heart rate that accompanies physical activity”. Perhaps this technique will someday become a useful/more widely used tool to assess vascular health and risk of brain degeneration/dementia.