Journal Article 1 Mention
Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia
Jeff D. Williamson2019
Nicholas M. PajewskiAlexander P. Auchus
Top 5% · 95th percentile
1,221 citations · Psychiatry and Mental health
Open Access

TLDR

Lowering blood pressure more aggressively in older adults did not clearly prevent dementia, but it did help reduce mild memory and thinking problems.

Summary

1 Study Aim

The study set out to determine whether lowering systolic blood pressure (the top number in a blood pressure reading) to below 120 millimeters of mercury (mm Hg) would reduce the risk of developing dementia, compared to a less strict goal of below 140 mm Hg, in adults with high blood pressure but without diabetes or a history of stroke. The researchers wanted to see if stricter blood pressure control could help prevent dementia in people with high blood pressure.

2 Study Design

This was a randomized clinical trial conducted at 102 sites in the United States and Puerto Rico. The study included adults aged 50 years or older who had high blood pressure but did not have diabetes or a history of stroke. Participants were randomly assigned to one of two groups: one group aimed for a systolic blood pressure below 120 mm Hg (intensive treatment), and the other aimed for below 140 mm Hg (standard treatment). A total of 9,361 people took part, and most completed at least one follow-up test of memory and thinking. The median time participants received the intervention was about 3.3 years, and the total follow-up lasted about 5.1 years. The researchers compared two groups of older adults with high blood pressure to see if stricter blood pressure goals affected memory and thinking over several years.

3 Findings

The study found that aiming for a systolic blood pressure below 120 mm Hg did not significantly lower the risk of developing probable dementia compared to the less strict goal of below 140 mm Hg. However, the stricter blood pressure control did lead to a significant reduction in the risk of developing mild cognitive impairment (MCI), which is a condition where memory and thinking problems are noticeable but not severe enough to be called dementia. The combined outcome of either MCI or probable dementia was also lower in the intensive treatment group. The authors note that the study ended earlier than planned and had fewer cases of dementia than expected, which may have limited their ability to detect a difference in dementia rates. They suggest that while intensive blood pressure control may help prevent early memory problems, its effect on preventing dementia is still uncertain. Lowering blood pressure more aggressively helped prevent early memory problems, but it did not clearly stop dementia from developing.

Abstract

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, Setting, and Participants: 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 blood pressure goal of either less than 120 mm Hg (intensive treatment group; n = 4678) or less than 140 mm Hg (standard treatment group; n = 4683). Main Outcomes and Measures: 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 [35.6%]), 8563 (91.5%) completed at least 1 follow-up cognitive assessment. The median intervention period was 3.34 years. During a total median follow-up of 5.11 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; hazard ratio [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) 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). Conclusions and Relevance: 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. Because of early study termination and fewer than expected cases of dementia, the study may have been underpowered for this end point. Trial Registration: ClinicalTrials.gov Identifier: NCT01206062.

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