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Intensive blood pressure control may lessen cognitive loss

The study adds to growing evidence about the health benefits of controlling blood pressure.Digitalskillet / iStock / Thinkstock

MCI is a condition in which people have more difficulty with thinking, remembering, and reasoning than normal for people their age. It’s not as severe as dementia, which is a form of cognitive loss that interferes with daily life. MCI is an established risk factor and often a precursor for dementia. There have been no proven interventions that prevent or delay the incidence of MCI or dementia.

Studies suggest that high blood pressure, or hypertension, may increase the risk for cognitive impairment and dementia later in life. High blood pressure is very common in people over the age of 50 and is a leading risk factor for heart disease, stroke, and kidney failure. However, no studies had definitely shown that strict control of hypertension could reduce the chances of developing cognitive impairment.

The Systolic Blood Pressure Intervention Trial (SPRINT) was a large, randomized clinical trial that compared intensive blood pressure control (a systolic blood pressure target of less than 120 mmHg) with a standard target (less than 140 mmHg). SPRINT was stopped in August 2015 after 3.3 years of treatment, when the major benefits of intensive blood pressure management on reducing mortality and cardiovascular disease were established.

SPRINT Memory and Cognition in Decreased Hypertension (SPRINT MIND) was an integral aspect of the initial design for SPRINT. It aimed to address whether intensive blood pressure control would reduce the risk of developing dementia and MCI. Although the blood pressure management intervention was stopped early, development of dementia and MCI were assessed for the full planned five years.

SPRINT participants were adults 50 years and older who were at high risk for cardiovascular disease but had no history of stroke or diabetes at the start of the trial. Between November 2010 and March 2013, more than 9,300 participants were randomly assigned to intensive or standard treatment. For SPRINT MIND, participants with high blood pressure were given cognitive assessments. More than 90% had at least one more cognitive assessment during follow-up visits. The research team, which was led by Dr. Jeff D. Williamson at the Wake Forest School of Medicine, reported their results online on January 28, 2019, in JAMA.

The team found that there were fewer dementia cases diagnosed in the intensive treatment group than the standard treatment group (149 vs. 176). However, this difference wasn’t large enough to prove it didn’t happen by chance.

The team notes that the study had fewer cases of dementia than expected. Further, because the blood pressure management intervention was stopped early, participants were treated for a shorter period than originally planned. These issues may have weakened the ability to detect differences in dementia cases between the treatment groups.

The researchers found that the intensive treatment was safe for the brain. It also appeared to reduce the risk of MCI by about 20%.

“The fact that there was still an MCI result when the study was cut short makes these results encouraging,” explains Dr. Laurie Ryan of NIA’s Division of Neuroscience. “Much like we have research-based interventions for heart health and cancer prevention, we hope to have guidance based on this and subsequent studies that will more definitively show how to slow or even stop dementia well before symptoms appear.”

People should consult with their healthcare providers to decide the best blood pressure goals for themselves and discuss how to reach those goals.