Intensive blood pressure control ‘may slow age-related brain damage’
Intensive blood pressure control may be the key to brain health in later life, scientists say.
A new study found intense control was more effective at slowing the accumulation of white matter lesions than standard treatment of high blood pressure.
A previous study by the same research group showed the treatment lowered the chances of people developing mild cognitive impairment.
Dr Walter Koroshetz, director of the National Institutes of Health’s (NIH) National Institute of Neurological Disorders and Stroke, said: “These initial results support a growing body of evidence suggesting that controlling blood pressure may not only reduce the risk of stroke and heart disease but also of age-related cognitive loss.
“I strongly urge people to know your blood pressure and discuss with your doctors how to optimise control.
“It may be a key to your future brain health.”
In an American study, researchers used magnetic resonance imaging (MRI) to scan the brains of participants.
White matter lesions, which appear bright white on MRI scans, represent an increase in water content and reflect a variety of changes deep inside the brain.
This includes the thinning of myelin – a white fatty coating that protects nerve fibres, leaky brain blood vessels, or multiple strokes.
These changes are associated with high blood pressure, or hypertension.
A number of studies have indicated that people with hypertension have a greater chance of accumulating white matter lesions and also of experiencing cognitive disorders and dementia later in life.
The results of the study, using data from a clinical trial called Sprint Memory and Cognition in Decreased Hypertension (Mind), have been published in the Journal of the American Medical Association.
More than 9,300 adults who were aged at least 50 and had a high risk of cardiovascular disease received either standard treatment, which lowered systolic blood pressure to less than 140 mm Hg.
Or they received intensive treatment to lower the same pressure reading below 120 mm Hg.
Researchers compared brain scans of 449 participants that were taken at enrolment, to scans taken four years later.
The average increase in total volume of white matter lesions on scans of the intensive treatment group was 0.92 cm3.
This was compared to the 1.45 cm3 seen on scans from the standard treatment participants.
Dr Richard Hodes, director of the NIH’s National Institute on Aging, said: “These findings on white matter lesions – primarily in the aggressive control of blood pressure – are encouraging as we continue to advance the science of understanding and addressing the complexities of brain diseases such as Alzheimer’s and related dementias.”
Scientists acknowledge a number of limitations in the study including the short follow-up period and the relatively small sample size.
A separate study published in the same journal looked at patterns of blood pressure in midlife that extend to later life.
It found high blood pressure which extends to late life, or high blood pressure in midlife followed by low blood pressure later in life was associated with increased risk for dementia, compared to normal blood pressure.
The observational study included 4,761 participants who had blood pressure measurements taken over 24 years at five visits.
During a fifth visit a detailed neurocognitive evaluation was conducted, and a sixth visit featured a dementia assessment.
There were 516 new cases of dementia diagnosed between the fifth and sixth visits.
Sustained hypertension in midlife to late life, and a pattern of midlife hypertension and late-life hypotension were associated with increased risk for subsequent dementia.
Researchers at Johns Hopkins University School of Medicine acknowledged the findings may have been biased because of the increased likelihood participants with higher blood pressure and poorer cognition during midlife dropped out of the study.
Dr Jana Voigt, head of research at Alzheimer’s Research UK, said: “Research is increasingly pointing to midlife as the time to act, with high blood pressure at this time associated with the greatest risk of the condition.
“It’s difficult to draw full conclusions from the research as some key control groups are missing.
“Researchers will need to confirm these findings in future studies and consider how they may relate to dementia risk reduction guidelines.”