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Hemodynamic influences of losartan on the brain in hypertensive patients

Naohiko Oku1, Kazuo Kitagawa, Masao Imaizumi

  • 1Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka, Japan. oku@medone.med.osaka-u.ac.jp

Hypertension Research : Official Journal of the Japanese Society of Hypertension
|June 23, 2005
PubMed

Insights

Losartan effectively lowers blood pressure in hypertensive patients without altering cerebral blood flow or perfusion reserve. This suggests its potential benefit for cerebral circulation in essential hypertension.

Area of Science:

  • Neurology
  • Cardiology
  • Pharmacology

Background:

  • Cerebral hemodynamic effects of angiotensin II receptor blockers are not well understood.
  • Essential hypertension poses risks to cerebral circulation.

Purpose of the Study:

  • To evaluate the impact of losartan on cerebral hemodynamics in hypertensive patients.
  • To assess regional cerebral blood flow and perfusion reserve before and after losartan treatment.

Main Methods:

  • Positron emission tomography (PET) with [O-15] labeled water was used to measure regional cerebral blood flow.
  • Cerebral perfusion reserve was assessed using acetazolamide challenge in a subset of patients.
  • Ten patients with essential hypertension were studied before and after 8-23 weeks of oral losartan treatment.

Main Results:

  • Losartan significantly reduced systemic blood pressure (153.8/96.0 mmHg to 133.4/83.6 mmHg).
  • No significant changes were observed in global or regional cerebral blood flow.
  • Cerebral perfusion reserve remained unchanged after losartan treatment.

Conclusions:

  • Losartan's blood pressure-lowering effect does not negatively impact cerebral hemodynamics in mild to moderate hypertension.
  • Losartan may be a beneficial addition to antihypertensive regimens for preserving cerebral circulation in essential hypertension.

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