There's more reason to keep your blood pressure in check: A new study shows that mild to moderate hypertension can make people more forgetful or slow their ability to think. This loss in cognitive skills over time could lead to dementia, researchers suggest.

Dementia is an irreversible brain disorder that causes memory loss, personality changes, and problems with reasoning, orientation, and personal care. The most common form of the illness is Alzheimer's disease, which makes up 60-80% of all cases.

"Most patients [eventually] have dementia. It's always preceded by a more subtle loss of thinking skills," says study author Gary A. Ford, professor of pharmacology at the Institute for the Health of the Elderly at University of Newcastle-Upon-Tyne in the United Kingdom. "Treating hypertension, even in the modest levels, may more likely be associated with reducing the likelihood of progressing to dementia."

The link between high blood pressure and loss in cognitive abilities is not new. Previous research has found a link between hypertension in midlife and reduced brain function years later. These studies, however, had a smaller group of participants, says Noel Bairey Merz, medical director of the Preventive Cardiac Center at the Cedar-Sinai Medical Center in Los Angeles. Plus, she notes that Ford's research was "cleaner" in its approach.

"[Ford and colleagues] prospectively identified a sample," says Bairey Merz. "They went out and they said, 'This is who we're going to study and match them for other factors that could potentially influence their cognition.'"

When analyzing data, Ford's group accounted for illnesses, drug therapy, and education levels of all participants. There were 107 men and women with untreated moderately high blood pressure (averaging 164/89), and 116 people with normal blood pressure (averaging 131/74). The average age in both groups was 76.

Investigators gave all participants several tests to measure memory capacity and reaction times. They found subjects with high blood pressure were slower in reaction time and had poorer memory than the normal blood-pressure group.

The differences in mental capacities were subtle, says Bairey Merz. "At this level, you would probably not be able to say to someone, 'Oh, I could tell your blood pressure is up, because you forgot to pick the kid up.'"

The results are significant enough to encourage researchers to conduct further studies. Ford says his group is now looking into what happens with cognitive skills when hypertension is treated with medication.

In the meantime, both Ford and Bairey Merz agree that high blood pressure is something that should concern people, whether or not mental abilities are affected.

"They should be concerned anyway, because of the other well-known effects of hypertension on developing heart attacks and stroke," says Ford.

Bairey Merz, on the other hand, suggests that Ford's study provides more support to the notion that it's better not to take any chances with high blood pressure. "I would use this [study] as a call to arms."

(From HealthWatch)