Strict blood pressure control may protect against cognitive decline
A new study has observed an association between patients’ blood pressure control and their number of white matter brain lesions: a key measure of age-related cognitive decline.
Previous data from the National Institutes of Health’s (NIH; MA, USA) Systolic Blood Pressure Intervention Trial (SPRINT) demonstrated that strict blood pressure correction — following treatment that reduced patients’ systolic blood pressure measurements below 120 mm Hg — lowered patients’ risks of developing mild cognitive impairment. Now, new SPRINT data has demonstrated additional benefits of this intensive treatment intervention on reducing patients’ white matter lesion accumulation, compared with standard hypertension therapy.
The white matter of the brain comprises millions of axons: nerve projections that allow neurons to communicate. Axons are sheathed in a fatty layer of myelin, allowing for salutatory conduction, or more rapid neuronal cell communication.
White matter lesions are associated with age-related cognitive decline and represent increased brain water content; this can result from myelin thinning, increased cranial vascular permeability and stroke occurrence, amongst others causes.
Several studies have suggested that increased risk of white matter lesioning is associated with hypertension.
To directly evaluate this, research published in the Journal of the American Medical Association describes a randomized controlled trial, called SPRINT Memory and Cognition in Decreased Hypertension (MIND), to determine if strict hypertension correction could prevent and/or slow the progression of white matter lesion formation and associated age-related brain disorders.
Researchers compared brain MRI scans of 449 hypertensive patients receiving either standard blood pressure treatment — to reduce their systolic measurements to below 140 mm Hg — or intensive blood pressure treatment — to reduce their systolic measurements to below 120 mm Hg — at baseline and 4 years follow-up.
Over the course of the study, researchers observed that patients receiving standard blood pressure treatment experienced an average white matter lesion volume increase of 1.45 cm3. By contrast, patients in receipt of intensive treatment had an average white matter lesion volume increase of 0.92 cm3.
Richard Hodes, Director of the NIH’s National Institute on Aging (NIA; MA, USA), commented: “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.”
Lenore Launer, contributing study author and a Senior Investigator in the NIA Laboratory of Epidemiology and Population Sciences, added: “SPRINT MIND has produced promising initial results in the battle against the nation’s growing problem with aging brain disorders. Both the brain scans and the cognitive tests reinforce the potential benefits that intensive blood pressure management may have on the brain.”
“We hope that these findings will become the foundation for future studies on how to protect the brain throughout a person’s life,” Launer concluded.
Sources:
The SPRINT MIND Investigators for the SPRINT Research Group. Association of Intensive vs Standard Blood Pressure Control With Cerebral White Matter Lesions. JAMA; 322(6); 524—534. doi:10.1001/jama.2019.10551 (2019);