Around 9,000 adults were randomly assigned to either intensive or standard systolic blood pressure (sBP) control. Researchers followed them for about five years, tracking cognitive function and dementia risk.
The primary outcome narrowly missed statistical significance. However, secondary outcomes showed a clear benefit—those with intensive sBP control (<120 mmHg) had significantly lower rates of mild cognitive impairment and probable dementia compared to those with a target of <140 mmHg.
While additional trials are needed to confirm these findings, this study found no evidence of harm from lowering sBP below 120 mmHg.
J A M A
Randomized
January 2019
Importance :
There are currently no proven treatments to reduce the risk of mild cognitive impairment and dementia.
Objective:
To evaluate the effect of intensive blood pressure control on risk of dementia.
Design:
Randomized clinical trial 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.
Randomization began on November 8, 2010. The trial was stopped early for benefit on its primary outcome (a composite of cardiovascular events) and all-cause mortality on August 20, 2015.
The final date for follow-up of cognitive outcomes was July 22, 2018.
Interventions:
Participants were randomized to a systolic BP goal of either
- <120 mm Hg (intensive treatment group; n = 4678)
- <140 mm Hg (standard treatment group; n = 4683)
- The risk of mild cognitive impairment (14.6 vs 18.3 cases per 1000 person-years; HR=0.81; 95% CI, 0.69-0.95, P<0.05) and
- The combined rate of mild cognitive impairment or probable dementia (20.2 vs 24.1 cases per 1000 person-years; HR=0.85; 95% CI, 0.74-0.97, P<0.05).
- The primary cognitive outcome was occurrence of adjudicated probable dementia.
- Secondary cognitive outcomes included adjudicated mild cognitive impairment and a composite outcome of mild cognitive impairment or probable dementia.