Brain Disease and High Blood Pressure

Research recently published in the medical journal, Neurology, found a link between high blood pressure and brain disease. As many as half of American adults have high blood pressure and do not even know it. High blood pressure, or hypertension, occurs when the force of blood flow through your blood vessels is consistently too high.

Blood pressure is determined by the amount of blood your heart pumps and the amount of resistance to the flow in your arteries, the narrower your arteries and the more blood pumped the higher your blood pressure will be. Individuals can have high blood pressure for years without any symptoms, but damage to your vessels and heart continues, increasing risk of serious health complications such as heart attack or stroke. A healthy blood pressure is 120/80 or less, while high blood pressure is 140/90 or above. The larger number is the systolic blood pressure, or the pressure in blood vessels when our heart beats, while the lower number is diastolic blood pressure and refers to the pressure when the heart is at rest.

The published research, from researchers at the Rush Alzheimer’s Disease Center at Rush University Medical Center in Chicago, aimed to study how blood pressure changes with age and disease impacts the brain. Previous studies have shown links between blood pressure and complications such as stroke or neurodegenerative disease like dementia. " In this study, we wanted to examine the relationship of blood pressure across a range of values -- not just high but also normal and low -- to the two most common causes of stroke and dementia," said Dr. Zoe Arvanitakis, study author. For the study 1,288 older people were studied until death, for an average of 8 years with an average age of death at 89 years. Two-thirds of the participants had a history of high blood pressure, with 87% on blood pressure medication, and 48% having had one or more brain lesions. Blood pressure was taken yearly for each participant and autopsies conducted after death, the average blood pressure was 134/71.

Researchers found that higher blood pressure correlated with increased likelihood of brain lesions. Specifically, systolic blood pressure of 147 translated to 46% increased risk of having large brain lesions and a 36% chance of greater risk for small lesions. Higher systolic blood pressure was also associated with an increase in the tangles in brain tissue, a common sign of Alzheimer’s disease. Higher diastolic blood pressure correlated with brain lesions, with 28% greater risk of one or more lesions. However, the results did not change when other factors that could affect risk of brain lesions, such as high blood pressure drugs, were controlled. Limitations of the study included only recording blood pressure once a year and that earlier in life blood pressure records were not available for participants.

"While our findings may eventually have important public health implications for blood pressure recommendations for older people, further studies will be needed to confirm and expand on our findings before any such recommendations can be made," said Dr. Arvanitakis.

To read this study click here.. To learn more about how blood pressure works watch the video below!

American Heart Association, Mayo Clinic