Systolic Blood Pressure and Dementia Risk

About 9,000 adults were randomized to receive tight or less-tight systolic blood pressure control. They were followed for about 5 years for cognition and dementia outcomes.

Although the primary outcome was almost significant, the secondary outcomes were truly significant for improvement of mild cognitive impairment or probable dementia with intensive systolic blood pressure <120 mmHg over those who achieved sBP <140 mmHg.

While further trials are needed to clarify the above findings, there appears to be no harm of lowering the sBP down to <120 mmHg in this study.

GT

Also see:

Cognition posts

Hypertension posts


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)

Outcomes:

  • 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.

Results:  

  • Among 9361 randomized participants (mean age, 67.9 years; 3332 women), 8563 completed at least 1 follow-up cognitive assessment.

  • The median intervention period was 3.3 years.

  • During a total median follow-up of 5.1 years, adjudicated probable dementia occurred in 149 participants in the intensive treatment group vs 176 in the standard treatment group (7.2 vs 8.6 cases per 1000 person-years; HR, 0.83; 95% CI, 0.67-1.04).

  • Intensive BP control significantly reduced:

    • 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).

Conclusions:

Among ambulatory adults with hypertension, treating to a systolic blood pressure goal of <120 mm Hg compared with a goal of <140 mm Hg did not result in a significant reduction in the risk of probable dementia.

Because of early study termination and fewer than expected cases of dementia, the study may have been underpowered for this end point.

 
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