Orthostatic hypotension link to dementia
Thursday October 13th, 2016
Dutch researchers have linked episodes of low blood pressure to dementia risk.
Dr Arfan Ikram, of Erasmus Medical Centre, the Netherlands, and colleagues, analysed figures from a study of 6,204 men and women, some of whom with orthostatic hypotension, that is, low blood pressure when suddenly standing up.
This condition can cause dizziness and brief episodes of reduced blood flow to the brain, known as hypoperfusion, which has previously been linked to brain dysfunction in the elderly.
Participants were mostly in their 60s at recruitment. Those who showed a drop of more than 20mmHg in their systolic blood pressure or 10 mmHg in their diastolic pressure within three minutes of standing were classed as having orthostatic hypotension.
Over the subsequent 24 years, the 19% who had orthostatic hypotension at the start, had a 15% increased rate of all dementia types, including Alzheimer's disease, vascular dementia, Parkinson's dementia, and other dementias.
The study is published in PLoS Medicine. A sub-group of the participants were observed not to have a compensatory increase in heart rate alongside the momentary drop in blood pressure. These individuals had an even higher rise in dementia risk, of 39% over the long-term.
People whose systolic blood pressure varied upon standing, but who did not meet the criteria for orthostatic hypotension, also had an 8% increased risk of dementia.
Dr Ikram and colleagues suggest that "brief episodes of hypoperfusion, elicited by sudden blood pressure drops, may lead to hypoxia [lack of oxygen] with detrimental effects on brain tissue."
They add that further studies are warranted to investigate the effects of hypoperfusion and treatment of orthostatic hypotension on markers of neurodegenerative disease and cognition.
Wolters, F. J. et al. Orthostatic Hypotension and the Long-Term Risk of Dementia: A Population-Based Study. PLoS Medicine 12 October 2016;doi: 10.1371/journal.pmed.1002143
Tags: Brain & Neurology | Elderly Health | Europe
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