October 11, 2018
Having high blood pressure at age 50 is linked to an increased risk for Alzheimer’s disease and other forms of dementia years later, according to a new report. The blood pressure need not even be in the treatment range. People whose systolic blood pressure — the top number in a blood pressure reading — was 130 were at increased risk for later dementia, even though treatment for high blood pressure with medications does not usually begin until someone’s pressure has reached 140.
The findings, published in the European Heart Journal, underscore the need to keep blood pressure in check to help avoid dementia later in life. A healthy blood pressure is generally regarded at 120/80 or below; and above 140/90 is considered as high blood pressure.
For the study, scientists looked at more than 8,000 men and women who were part of a large and ongoing study in Britain. They got blood pressure readings in 1985, when study participants were between the ages of 35 and 55. Blood pressure was again measured in 1991, 1997 and 2003, when many of the participants were in their 60s and 70s.
The health records of those in the study were followed through March of 2017. By that time, 385 had been diagnosed with dementia.
The researchers found that having a systolic blood pressure of 130 or greater at age 50 was associated with a 38 percent increased risk of dementia. The risk was independent of other cardiovascular risk factors like stroke or heart failure.
Developing high blood pressure at age 60 or 70, on the other hand, did not increase dementia risk, perhaps because it may take decades for high blood pressure to take a toll on the brain.
High blood pressure often has no symptoms. But it can, over many years, damage blood vessels throughout the body, including in the brain, where blood vessels can be extremely narrow.
Elevations in diastolic blood pressure, the lower number in a blood pressure reading, were not tied to an increased risk of dementia.
Earlier studies had found that various heart risk factors at midlife are also risk factors for Alzheimer’s disease. In addition to high blood pressure, being overweight, smoking, leading a sedentary life or having diabetes can all increase your risk of developing dementia years down the road.
If you are prescribed blood pressure drugs, it is important to keep taking them to keep blood pressure in check.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Jessica G. Abell, Mika Kivima¨ki, Aline Dugravot, et al: “Association between systolic blood pressure and dementia in the Whitehall II cohort study: role of age, duration, and threshold used to define hypertension.” European Heart Journal, June 13, 2018