Is controlling your blood pressure the key to keeping your mind sharp as you age?

The researchers aimed to see whether day-to-day variations in blood pressure were associated with cognitive decline. 

Modern advances in medicine and a greater awareness of our general health have meant that humans are living longer than ever before. However, longer lives lead to more age-associated illnesses. Cognitive decline is a common problem that people face as they age. Cognitive decline involves difficulty learning new things quickly, as well as  difficulty solving problems or remembering things.

Previous studies have shown that high blood pressure (blood pressure over 120/80 mmHg) leads to a greater risk of cognitive decline. In these studies, blood pressure was measured in a doctor’s office and not regularly. However, blood pressure can vary from day to day. Blood pressure variability has been associated with a higher risk of cardiovascular mortality (death from causes such as heart attack or stroke). It is not known whether day-to-day blood pressure variability affects cognitive decline. 

In this study, 485 patients were asked to measure their blood pressure at home every morning for 4 weeks.  Their blood pressure was also measured by a doctor twice during this 4-week period. Cognitive decline was measured using a standard questionnaire designed to measure awareness and memory. None of the patients showed signs of cognitive decline at the beginning of the study.

46 patients developed cognitive decline over an average of 7.8 years. As day-to-day blood pressure variability increased, there was a 48% increase in the risk of cognitive decline. There was no significant link between the two doctor-measured blood pressure readings and cognitive decline.  During the study some patients began taking medications for high blood pressure. This appeared to lessen the risk of cognitive decline. 

This study suggested that blood pressure variability was associated with cognitive decline. The authors also suggest that measuring blood pressure more frequently, at home might be better at predicting possible cognitive decline. 

This research is part of a larger study examining blood pressure. The research should be repeated with a study specifically designed to test if day-to-day blood pressure variability affects cognitive decline.