NEW YORK (Reuters Health) - High blood pressure is associated with worse brain function than normal blood pressure in people aged 60 and older, according to a report by doctors at Howard University Hospital in Washington, DC.
"Optimal control of blood pressure may be beneficial in attenuating the risk of cognitive decline as the population ages," they conclude.
Dr. Thomas Olabode Obisesan and associates used data from the Third National Health and Nutrition Examination Survey (NHANES III) to investigate whether abnormal blood pressure is independently associated with lower cognitive function in men and women between 60 and 74 years old at study entry.
They found that normal blood pressure (less than 120/80 mm Hg) was associated with the best cognitive performance in people aged 60 to 69, whereas individuals aged 75 to 79 with "pre-hypertension" (blood pressure up to 140/90 mm Hg) and individuals aged 80 or older with moderate hypertension had the best cognitive performance.
Having "stage 1" hypertension -- defined as a systolic blood pressure (the top number in the BP reading) between 140 and 159 mm Hg, and a diastolic pressure between 90 and 99 mm Hg -- was negatively associated with cognitive performance in the older age groups. The association between elevated blood pressure and poorer cognitive performance was most notable in individuals aged 70 to 79 years and in those over 80 years, the researchers note.
In people with hypertension, the investigators say, control of blood pressure attenuated the hypertension-related cognitive loss.
Obisesan thinks doctors need to "double their efforts, through ongoing monitoring, to identify trends toward increases in blood pressure in their patients and institute treatment early rather than later."
"Even if blood pressure treatment and control results in mild attenuation of the Alzheimer's disease risk, benefits to the population and the public health impact can be substantial given the overall prevalence of hypertension in the United States," Obisesan said.
SOURCE: Journal of the American Geriatrics Society, March 2008.