Researchers at the National Institutes on Aging (NIA) of the National Institutes of Health in Bethesda, Md., compared otherwise healthy people with long-standing histories of well-controlled high blood pressure in two age groups (56-69 and 70-84 years) with individuals of the same age with normal blood pressures. All study participants received structural brain-imaging scans and neuropsychological tests.
"None of the patients with high blood pressure had ever had a stroke, and none had other diagnosed medical conditions," says Gene E. Alexander, Ph.D., NIA researcher and senior investigator in the study. "But they had more brain atrophy than those with normal blood pressure, and this effect was worsened by aging." There is also a reduction in memory ability in those with high blood pressure, and this that may also be accelerated with aging, he added.
Aging alone causes some loss of cognitive skills, Alexander notes, but the loss is accelerated when blood pressure is high, and changes occur despite the patients receiving drug therapy to control blood pressure.
The study's findings point to a type of old-age brain deterioration that is distinct from such conditions as Alzheimer's disease, Alexander notes. Furthermore, the results suggest that current treatment practices for hypertension in the elderly may not be sufficient to ward off the combined effects of high blood pressure and aging on the brain, where the advanced elderly appear most vulnerable to the long-standing effects of hypertension. "We still have much to learn about effects of the aging process," says Alexander, "but it's very important to understand how high blood pressure affects the brain so we can find a way to prevent the loss of cognitive function and improve the quality of life in the elderly."
Media advisory: Dr. Alexander can be reached at (301) 594-3134. Fax is (301) 402-0595. (Please do not publish telephone numbers.