Bethesda, MD—A major study found no statistically significant difference between standard and intensive treatment in the proportion of participants who were diagnosed with dementia, defined as the primary outcome.

Secondary results were more promising, however, suggesting that intensive treatment might reduce the risk of mild cognitive impairment (MCI) and the combined risk of MCI and dementia.

The final, peer-reviewed results from the Systolic Blood Pressure Intervention Trial (SPRINT) Memory and Cognition in Decreased Hypertension (SPRINT MIND) trial were published recently in JAMA.

“The fact that there was still an MCI result when the study was cut short makes these results encouraging,” explained Laurie Ryan, PhD, program lead for SPRINT MIND and chief of the Dementias of Aging Branch at the National Institutes of Aging.

Researchers point out that, overall, there were fewer cases of dementia than anticipated and that the trial was ended early because of positive results on cardiovascular (CV) outcomes, which could have affected cognitive impairment–related results.

The randomized clinical trial, which began in 2010, was conducted at 102 sites in the United States and Puerto Rico among adults aged 50 years or older with hypertension but without diabetes or history of stroke. The trial was stopped early in 2015 for benefit on its primary outcome, protection against a composite of CV events, and all-cause mortality. The final date for follow-up of cognitive outcomes was July 22, 2018.

Participants were randomized to a systolic blood pressure goal of either less than 120 mm Hg, defined as the intensive treatment group, or less than 140 mm Hg, defined as the standard treatment group. The primary cognitive outcome was occurrence of adjudicated probable dementia, while secondary cognitive outcomes included adjudicated MCI and a composite outcome of MCI or probable dementia.

For the more than 8,500 participants who completed at least one follow-up cognitive assessment over a total median follow-up of 5.11 years, adjudicated probable dementia occurred in 149 participants in the intensive-treatment group versus 176 in the standard-treatment group (7.2 vs. 8.6 cases per 1,000 person-years; hazard ratio [HR], 0.83; 95% CI, 0.67-1.04), according to the study.

Results indicate that intensive BP control significantly reduced the risk of MCI (14.6 vs. 18.3 cases per 1,000 person-years; HR, 0.81; 95% CI, 0.69-0.95) and the combined rate of MCI or probable dementia (20.2 vs. 24.1 cases per 1,000 person-years; HR, 0.85; 95% CI, 0.74-0.97).

“Among ambulatory adults with hypertension, treating to a systolic blood pressure goal of less than 120 mm Hg compared with a goal of less than 140 mm Hg did not result in a significant reduction in the risk of probable dementia,” study authors write. “Because of early study termination and fewer than expected cases of dementia, the study may have been underpowered for this end point.”

“This is a landmark study in that it is the first trial of its size and scope to look at a modifiable risk factor for dementia and MCI,” explained coauthor Lenore J. Launer, PhD, a senior investigator in the National Institute of Aging Laboratory of Epidemiology and Population Sciences. “The study had a carefully designed hypothesis, used approved appropriate tools to assess dementia and MCI, was blinded for diagnosis, and got a good sample of older people.”

“This study is in line with where the field of dementia research is going: preventing memory loss earlier,” added Ryan. “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.”

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