MONDAY, Oct. 14, 2002 (HealthDayNews) -- Older blacks who keep their high blood pressure in check by taking medication may be able to avoid losing some of their mental edge as they age.
That's the conclusion of a large, five-year study that found older blacks who took medication to control their blood pressure reduced their risk of cognitive impairment by 38 percent.
While previous studies have shown that whites were able to stave off mental decline if they controlled their blood pressure with medication, this is the first study to show similar results in blacks, says study author Michael D. Murray.
Murray is a scientist and pharmacist at the Regenstrief Institute in Indianapolis. His study appears in today's issue of the Archives of Internal Medicine.
The study is particularly significant because blacks are prone to high blood pressure.
"Blacks in the U.S. have among the highest rates of hypertension in the world, and it is especially great in older adults as hypertension increases with age," Murray says.
It's still not known how controlling blood pressure preserves mental agility, Murray notes. "It's really not well known how high blood pressure intermediates cognitive impairment."
The study included 1,617 black men and women with a minimum age of 65. Of those, 1,050 had high blood pressure and 753 were on medication to control it. Those taking medication were using a variety of types and doses and had been taking them for different lengths of time, Murray says.
"They (antihypertensives) all seem to have an effect, with the exception of beta blockers," which were not found to be protective at all, he says.
It's not known why beta-blockers didn't preserve mental functioning the way other antihypertensives did, Murray says. Further studies may show that some antihypertensives are better than others at preserving cognitive functioning, while some may prove to quicken mental decline, he says.
"If you preserve blood pressure into old age, you may preserve cognitive function, unless you have another risk factor (for mental decline) such as high cholesterol or smoking," Murray says.
All subjects were free of cognitive impairment at the start of the study. Declines in cognitive functioning were determined by standardized tests.
"The actual definition of cognitive impairment is a composite of different terms, including not only memory but language, recall and judgment," Murray says. "The notion now is that there may be different lifestyles and medications that may be available or will soon be discovered that can prevent that progression from occurring."
Dr. Mahboob Rahman, an assistant professor of medicine at Case Western Reserve University in Cleveland, treats many patients with high blood pressure and kidney disease. He says he has heard that "the long-term treatment of hypertension does improve cognitive function."
He believes many older people suffer repeated small "infarcts" -- or minor heart attacks -- due to high blood pressure that can result in mental decline.
Since controlling blood pressure protects the kidneys and liver, "I think it's reasonable to expect it would protect cognitive function," Rahman says.
Murray says he hopes his study will be an incentive for everyone with high blood pressure, but especially blacks, to adhere to their prescribed medication.
"This study gives another good reason for taking your blood pressure meds," he says.
What To Do
To learn more about controlling high blood pressure, visit the National Heart, Lung, and Blood Institute or the American Heart Association.
