Is High Blood Pressure Self-Protection for the Brain?

Esther Ah Warnert, Jonathan C Rodrigues, Amy E Burchell, Sandra Neumann, Laura E Ratcliffe, Nathan E Manghat, Ashley D Harris, Zoe H Adams, Angus K Nightingale, Richard G Wise, Julian F Paton, Emma C Hart*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

36 Citations (Scopus)
255 Downloads (Pure)

Abstract

RATIONALE: Data from animal models of hypertension indicate that high blood pressure may develop as a vital mechanism to maintain adequate blood flow to the brain. We propose that congenital vascular abnormalities of the posterior cerebral circulation and cerebral hypoperfusion could partially explain the etiology of essential hypertension, which remains enigmatic in 95% of patients.

OBJECTIVE: To evaluate the role of the cerebral circulation in the pathophysiology of hypertension.

METHODS AND RESULTS: We completed a series of retrospective and mechanistic case-control magnetic resonance imaging and physiological studies, in normotensive and hypertensive humans (n=259). Interestingly, in humans with hypertension, we report a higher prevalence of congenital cerebrovascular variants; vertebral artery hypoplasia and an incomplete posterior circle of Willis, which were coupled with increased cerebral vascular resistance, reduced cerebral blood flow and a higher incidence of lacunar type infarcts. Causally, cerebral vascular resistance was elevated before the onset of hypertension and elevated sympathetic nerve activity (n=126). Interestingly, untreated hypertensive patients (n=20) had a cerebral blood flow similar to age-matched controls (n=28). However, participants receiving anti-hypertensive therapy (with blood pressure controlled below target levels) had reduced cerebral perfusion (n=19). Finally, elevated cerebral vascular resistance was a predictor of hypertension suggesting it may be a novel prognostic and/or diagnostic marker (n=126). <Conclusions: Our data indicate that congenital cerebrovascular variants in the posterior circulation and the associated cerebral hypoperfusion may be a factor in triggering hypertension. Therefore lowering blood pressure may worsen cerebral perfusion in susceptible individuals.

Original languageEnglish
Pages (from-to)e140-e151
Number of pages12
JournalCirculation Research
Volume119
Issue number12
Early online date26 Sep 2016
DOIs
Publication statusPublished - Dec 2016

Structured keywords

  • CRICBristol

Keywords

  • body mass index
  • human
  • hypertension
  • magnetic resonance imaging
  • pathophysiology

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    Warnert, E. A., Rodrigues, J. C., Burchell, A. E., Neumann, S., Ratcliffe, L. E., Manghat, N. E., Harris, A. D., Adams, Z. H., Nightingale, A. K., Wise, R. G., Paton, J. F., & Hart, E. C. (2016). Is High Blood Pressure Self-Protection for the Brain? Circulation Research, 119(12), e140-e151. https://doi.org/10.1161/CIRCRESAHA.116.309493