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BP Variation Linked to CVD, cerebrovascular disease
 
 
  MedPage Today
Published: May 10, 2010
 
If your blood pressure fluctuates up and down over time, you may be at increased risk of cerebrovascular disease, researchers said.
 
Action Points
 
Explain to interested patients that blood pressure variation over time, even without clinical hypertension, can be a possible ind icator of increased CVD risk.
 
In a cohort study, people 65 and older with high pressure were at greater risk of cerebrovascular disease (CVD), including infarcts and white matter hyperintensity volume, according to Adam Brickman, PhD, of Columbia University's College of Physicians and Surgeons, and colleagues.
 
But participants were also at higher risk if their blood pressure varied markedly across three separate measurements two years apart, Brickman and colleagues reported in the May issue of Archives of Neurology.
 
The two factors seemed to be additive, the researchers found, with those having the highest pressure and variability significantly more likely to have CVD than those in the lower categories.
 
Treatment of hypertension is known to reduce the risk of CVD, the researchers said, but the findings "suggest that management of (blood pressure) fluctuations, even in normotensive older adults, may be beneficial." Subclinical CVD in the elderly is increasingly recognized as important, the researchers noted, but it's not clear what determines such damage. To help clarify the issue, they looked at participants in a large epidemiological study of older adults in New York City.
 
Participants in the Washington Heights-Inwood Columbia Aging Project are assessed every two years for a range of factors, including blood pressure. For this analysis, the researchers looked at 686 nondemented participants with three blood pressure readings and a magnetic resonance image (MRI) of the brain during the third blood pressure measurement period.
 
For each participant, mean blood pressure at each visit was calculated as the sum of one-third systolic and two-thirds diastolic pressure and an arithmetic average was calculated across the three visits.
 
Participants were divided into two groups based on the median of 96.48 millimeters of mercury. They were then subdivided again based on the median standard deviation of fluctuations -- 7.21 millimeters of mercury.
 
The four groups were similar i n most factors except that those with the highest pressure and fluct uations were most likely to have been treated with antihypertensive medications, the researchers found.
 
The two groups with low fluctuations varied slightly more than 5% over the three measurements, while those in the two groups with high fluctuations varied about 14%, Brickman and colleagues said.
 
The volume of white matter hyperintensities increased across the groups monotonically, with the lowest volume in the low-pressure, low-fluctuation group and the highest in the high-pressure, high-fluctuation group. The linear trend was significant at P=0.02.
 
Older age was also significantly associated with greater white matter hyperintensity volume, at P<0.001, they reported.
 
Of the 686 participants, 31.3% (or 215) had had cerebral infarcts, and again the rate increased monotonically across the groups. The linear trend was significant atP=0.004.
 
The study cohort is large, ethnically diverse, and community-based, the researchers noted, and the neuroimaging protocol and morphometric analysis were standardized.
 
On the other hand, they said, blood pressure was longitudinal, but the MRI data were acquired only once, so that analysis was correlational.
 
 
 
 
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