Lowering one's blood pressure is beneficial not only for the heart, but also for the mind. For the first time, researchers have proved that lowering systolic blood pressure to 120 mm Hg or less reduces the risk of mild cognitive impairment, which in turn, reduces one's risk of developing Alzheimer's disease or dementia.
The findings were the result of the Systolic Blood Pressure Intervention Trial's (SPRINT) Memory and Cognition in Decreased Hypertension (MIND) study. The preliminary results of the SPRINT MIND study were presented at the Alzheimer's Association International Conference today.
The preliminary results of the trial, in which the University of Alabama at Birmingham and the UAB School of Medicine played major clinical and leadership roles, is the first time it has been proved that the risk of mild cognitive impairment and dementia can be reduced through high blood pressure treatment.
"We previously found that treating blood pressure intensively, to a goal of 120 mm Hg systolic, reduces cardiovascular events and mortality in people with hypertension," said Virginia Wadley Bradley, Ph.D., professor of medicine in the Division of Gerontology, Geriatrics and Palliative Care, and the co-lead of the committee that oversaw the SPRINT MIND trial. "Now the preliminary results of SPRINT MIND show that treating systolic blood pressure to this goal is better for the brain as well. Participants in the intensive treatment group (target 120 mm Hg) had a 19 percent lower risk of mild cognitive impairment (MCI), which is often a precursor to dementia, than participants in the standard treatment group with a systolic blood pressure goal of 140 mm Hg."
Researchers also discovered that treating hypertension by reducing systolic blood pressure to 120 mm Hg also reduces the total volume of white matter lesions in the brain.
The results of the SPRINT study, which were published in 2015, found that heart attacks, strokes, acute coronary syndrome, heart failure and death due to cardiovascular causes were reduced by almost one-third and risk of death was lowered by almost one-quarter in participants randomized to a systolic blood pressure goal of 120 mm Hg compared to those randomized to the usual goal of 140 mm Hg. More than 9,300 participants age 50 and older with high blood pressure were assigned to the trial.
UAB has participated in the SPRINT trial since it began in 2010, when it was selected by the NIH as one of five hubs to recruit and direct the 100 medical centers and clinics participating in the trial around the United States and Puerto Rico.
"UAB was selected and is able to be a part of this remarkable study because we put together a great team of investigators and staff to run the hub," said Cora E. Lewis, M.D., chair of the Department of Epidemiology in the School of Public Health and the co-principal investigator of the UAB hub. "We recruited a good diversity of clinics that could bring in diverse patients and achieve the study recruitment goals, we wrote an outstanding application, and we have a lot of relevant experience for all aspects of the trial. We are able to provide all of the logistical support, and we have the infrastructure to handle a trial of this scope and magnitude."
For the MIND study, the SPRINT participants, 270 of whom were enrolled at UAB, participated in the trial. The findings were accomplished with the help of a team of various physicians and nurses.
"We used a battery of standardized evaluations of memory and other thinking skills," Bradley said. "Staff in each clinic went through a rigorous certification process annually that allowed them to administer the tests. The results and performance over time were reviewed by a team of neurologists, neuropsychologists and geriatricians who were masked to participants' treatment goals."
In additional to clinical roles, UAB faculty also have leadership roles in the SPRINT MIND trial. Suzanne Oparil, M.D., principal investigator for the UAB hub of the SPRINT trial, UAB professor of medicine, and director of the Vascular Biology and Hypertension Program in UAB's School of Medicine, and Lewis are on the trial-wide steering committee and co-lead the morbidity and mortality committee. Lewis also leads the measurement procedures and quality control committee and serves on the executive committee for the study.
The study is also examining kidney disease function and, according to preliminary results, has found that there appears to be no serious harm to kidney function due to lowering systolic blood pressure to 120 mm Hg.