Blood Pressure and Ischemic Brain Injury

Association of Ambulatory Blood Pressure With Ischemic Brain Injury

Gary L. Schwartz; Kent R. Bailey; Thomas Mosley; David S. Knopman; Clifford R. Jack, Jr; Vincent J. Canzanello; Stephen T. Turner From the Division of Nephrology and Hypertension (G.L.S., S.T.T., V.J.C.), the Department of Diagnostic Radiology (C.R.J.), the Department of Neurology (D.S.K.), and the Department of Health Sciences Research (K.R.B.), Mayo Clinic College of Medicine, Rochester, Minn; and the Department of Geriatric Medicine (T.M.), University of Mississippi, Jackson

Cerebral white matter hyperintensities on brain MRI (leukoaraiosis) are associated with increased risk of stroke and dementia.
To assess the relationships of blood pressure level and circadian pattern with leukoaraiosis, we obtained 24-hour ambulatory blood pressure recordings and brain magnetic resonance images in 343 white and 267 black adults who were members of sibships that had 2 siblings with essential hypertension.
In multiple linear regression models, factors associated with greater leukoaraiosis in both racial groups included age (P 0.002), homocysteine levels (P 0.006), and brain volume (P 0.008).
In blacks, ambulatory blood pressure measures associated with greater leukoaraiosis were higher awake, asleep, and 24-hour systolic and diastolic levels (P 0.009 for each).
In addition, there was a trend for smaller nocturnal declines in systolic and diastolic levels (ie, nondipping patterns) to be associated with greater leukoaraiosis, and all of these associations, except nondipping of diastolic level, remained or became significant after controlling for office blood pressure (P<0.05>
However, similar to findings in blacks, nondipping of systolic and diastolic ambulatory blood pressure levels were each associated with greater leukoaraiosis (P 0.008), and all of these associations remained or became significant after controlling for office blood pressure (P 0.009 for each).
Higher ambulatory blood pressure levels and a nondipping circadian pattern contribute to greater leukoaraiosis volume after controlling for office blood pressure.

Keywords: ambulatory blood pressure • leukoaraiosis • predictors • hypertension • target organ injury

Hypertension, June, 2007,Vol.49, №6; p.1228.
© 2007 American Heart Association, Inc.