A new study published in the journal Neurology finds that the older people having higher-than-normal blood pressure may have more brain disease signs, specifically brain lesions. The researchers also found an association between higher blood pressure (BP) and more markers of Alzheimer’s disease, brain tangles.
Zoe Arvanitakis, Rush Alzheimer’s Disease Center at Rush University Medical Center in Chicago, and colleagues conducted the study to determine whether BP in later life was associated with signs of brain aging including plaques and tangles linked to Alzheimer’s disease, and brain lesions called infarcts — areas of dead tissue caused by blood supply blockage that can increase with age and can lead to stroke if undetected.
The range of a healthy blood pressure is less than or equal to 120/80 mmHg. High blood pressure is above 140/90 mmHg. Systolic blood pressure is the pressure in the blood vessels when the heart beats. Diastolic blood pressure is the pressure when the heart is at rest.
For the study, the researchers followed 1,288 older people until they died, which was an average of eight years later. The average age at death was 89 years. Documentation of their BP was done yearly and brain autopsy was conducted after their death. The average systolic BP for the participants was 134 mmHg and the average diastolic BP was 71 mmHg. 87 percent of the participants’ medication for high BP and two-thirds of them had a history of high BP. A total of 48 percent of the participants had one or more brain infarct lesions.
“BP changes with aging and disease, so we wanted to see what kind of impact it may have on the brain,” said Dr. Arvanitaki.
- The risk of brain lesions was higher in people with higher average systolic BP across the years.
- For a person with one standard deviation above the average systolic BP, for examp,le 147 mmHg versus 134 mmHg, there was a 46 percent increased risk of having one or more brain lesions, specifically infarcts.
- The effect of an increase by one standard deviation on the risk of having one or more brain infarcts was the equivalent of nine years of brain aging.
- Those with one standard deviation above the average systolic BP also had a 46 percent greater chance of having large lesions and a 36 percent greater risk of very small lesions.
- People with a declining systolic BP also had an increased risk of one or more brain lesions, so it was not just the level but also the declining BP that was associated with brain lesions.
- Higher average diastolic BP was also related to brain infarct lesions.
- People who had an increase of one standard deviation from an average diastolic BP, for example from 71 mmHg to 79 mmHg, had a 28 percent greater risk of one or more brain lesions.
- The results did not change when researchers controlled for other factors that could affect the risk of brain lesions, such as whether they used high BP drugs.
The researchers also found a link between higher average late-life systolic BP across the years before death and a higher number of tangles, but not plaques, while looking for signs of Alzheimer’s disease in the brain autopsy. Arvanitakis however, noted that this link is difficult to interpret and will need more research.
“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 Arvanitakis.
For more information log on to https://doi.org/10.1212/WNL.0000000000005951