A study has found that high blood pressure speeds the loss of memory and other cognitive abilities in the elderly, and causes their brains to shrink.
The study appeared in the July 1997 edition of Stroke, a journal of the American Heart Association.
The changes occur in spite of drug therapy being used to control blood pressure according the study.
The results suggest that more-effective treatment may be needed for elderly patients with high blood pressure.
Researchers at the National Institutes on Aging of the National Institutes of Health in Bethesda, Md., compared people with normal blood pressures in two age groups - 56-69 and 70-84 - with people who had longstanding histories of well-controlled high blood pressure.
Participants underwent brain-imaging scans to evaluate physical characteristics and neuropsychological tests to assess general intellectual function, short-term memory, attention span, language function and other areas.
None of the patients with high blood pressure had ever had a stroke, and none had other diagnosed medical conditions. But they had more brain atrophy than those with normal blood pressure, and this effect was worsened by aging.
Participants with high blood pressure also showed increased memory loss compared with the participants with normal blood pressure.
One of the study's possible limitations was the small number of patients evaluated - 27 with high blood pressure and 20 in the control group. The size of the groups was dictated by the labor involved in measuring the size of each person's brain.
The research did not explain the mechanism by which high blood pressure causes brain atrophy and memory loss.