Blood Pressure Brain Drain

Blood pressure changes may be associated with lower cognitive function

(RxWiki News) Having blood pressure that is too high or too low can be bad for your heart, but a blood pressure that's constantly changing may be bad for your mind.

A recent study found greater changes in blood pressure between doctor visits to be associated with decreased cognitive function (processing and understanding information) in old age among people at high risk for heart disease.

"Speak to your doctor about safely managing your blood pressure."

This study was led by Simon Mooijaart, PhD, of the Department of Gerontology and Geriatrics at Leiden University Medical Center in the Netherlands. The research team examined whether changes in blood pressure between doctor visits were associated with cognitive function in an elderly population.

The researchers used data from 5,461 participants in the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) who were between 70 and 82 years old. Study participants either had or were at risk for cardiovascular disease.

Systolic and diastolic blood pressure were measured at the beginning of the study and every three months following until follow-up (average of 3.2 years). Systolic blood pressure is a measure of blood pressure when the heart beats. Diastolic blood pressure is a measure of blood pressure in between heart beats. 

Four areas of cognitive function were tested at the end of the study: selective attention, how quickly participants processed information, immediate memory and delayed memory. 

Participants were presented with tests where they had to correctly identify colors, match information according to a key they were given, and try to recall pictures that they were shown.  Their performance was based on how many answers they got correct, and how long it took them to complete the tests.   

The researchers split participants into three groups for changes in blood pressure between visits: low, middle and high amounts of change. They defined 14.8 units (mm Hg) as a change in systolic blood pressure and 7.1 units as a change in diastolic blood pressure.

Several factors were taken into account which could have affected the results including age, sex, education, history of vascular disease, average blood pressure, history of diabetes, smoking status, cholesterol levels and body mass index (a measure of height and weight).

The researchers found that even after taking all of the above factors into account, greater changes in both systolic blood pressure and diastolic blood pressure were associated with poorer performance on all cognitive tests.

Specifically, they found it took participants in the low blood pressure change group 3.08 seconds less to complete one of the tests. For the other three tests, the low blood pressure change group got more correct answers than the other blood pressure groups.  

These findings suggest the importance of maintaining a stable blood pressure.

This study was published on July 30 in the BMJ.

The original PROSPER study was funded by a grant from Bristol Myers Squibb.

The authors declared no conflicts of interest.

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Review Date: 
July 26, 2013