A clinical trial involving 9361 older adults (50+) with hypertension but without diabetes or history of stroke has found that intensive control of blood pressure significantly reduced the risk of developing mild cognitive impairment.

While there was also a 15% reduction in dementia, this result did not reach statistical significance. This may have been due to the small number of new cases of dementia in the study groups.

Participants were randomly assigned to a systolic blood pressure goal of either less than 120 mm HG (intensive treatment) or less than 140 mm HG (standard treatment). They were then classified after five years as having no cognitive impairment, MCI or probable dementia.

The trial was stopped early due to its success in reducing cardiovascular disease. As a result, participants were on intensive blood pressure lowering treatment for a shorter period than originally planned. This impacted the number of cases of dementia occurring.

Hypertension affects more than half of Americans over age 50 and more than 75% of those older than 65.

https://www.eurekalert.org/pub_releases/2019-01/wfbm-lbp012419.php