Can variations in blood pressure lead to a decline in cognitive functions?

This study looked at the effect of variation in blood pressure on cognitive functions (such as memory, attention, calculation, and language) in older patients. The authors concluded that a higher variability in blood pressure was associated with impaired cognitive functions.

Cognitive impairment is more common later in life. This can involve dementia, memory loss, or a decline in a number of cognitive functions. Both high blood pressure (hypertension) and low blood pressure have been identified as risk factors for cognitive impairment. A fluctuation in blood pressure over time, also known as blood pressure variability (BPV), is believed to increase the risk of strokes and heart attacks. More studies are needed to examine the link between BPV and cognitive impairment.

353 people aged 65 years or older were included in this study. At the beginning of the study blood pressure was measured over 24 hours. A series of tests measured a wide range of cognitive functions (including memory, attention, abstract thinking, calculation, and perception). Changes in cognitive function were examined over a period of 5 years.

At the beginning of the study, increased daytime BPV was associated with poorer scores on the tests for cognitive function. Variability in both systolic blood pressure (pressure when the heart is contracting) and diastolic blood pressure (pressure when the heart is between beats) during the day were both linked to poorer cognitive function. This was independent of the patient's age, gender, education, or medical history. Variability in nighttime BPV had no effect on cognitive function. 

Cognitive decline over 5 years was also significantly greater for patients with increased daytime BPV. However, this relationship was no longer significant after accounting for age, gender, and years in education.

The authors concluded that increased BPV in older people is associated with poorer cognitive function and may increase cognitive decline over time.

Consult with your physician if you have any concerns regarding your cognitive function or blood pressure.