Study: High Blood Pressure Associated with Cognitive Decline

Metabolic syndrome (MetS) is associated with increased risk of cardiovascular disease. A new study published online in the Journal of the International Neuropsychological Society shows that MetS also plays a role in cognitive performance.

Bonnie Levine of the Division of Neuropsychology at the University of Miami in Miami, FL and colleagues there and at Columbia University, New York, NY looked at blood pressure, lipid levels, obesity and fasting glucose to see if there was a correlation between MetS and cognition.

They found that blood pressure was the strongest predictor of cognitive performance.

The subjects of the study, which is known as the Northern Manhattan Study were 1290 stroke-free patients from a largely Hispanic multi-ethnic urban community.

They were assessed at baseline and again at an average of 10 years later. During the second assessment, the participants got a full battery of cognitive tests. The mean age was 64 at baseline.

Although high blood pressure, obesity, dyslipidemia and impaired glucose metabolism have all been shown to have a negative effect on cognitive function, the researchers looked at the relative importance of these factors.

The team found that each condition was associated with a different aspect of mental performance.

“Lipid levels predicted language performance; obesity and glucose were predictors of visual/motor performance; impaired glucose was associated with reduced dexterity," they wrote.

None of the metabolic components uniquely predicted memory performance.

Blood pressure emerged as the most significant metabolic syndrome variable uniquely predicting cognition in the participants.

The authors are not sure why.

“The mechanism by which hypertension may lead to cognitive decline is controversial and both direct and indirect pathways have been proposed," they wrote.

Obesity itself does not directly contribute to cognitive decline they added, but it can contribute to the development of hypertension.

One limitation of the study was that only the participants who were alive and stroke-free 10 years after the study began could be included in the research.