Study on Blood Pressure Control and Dementia Prevention

Background on Dementia and Cognitive Impairment

A recent study explored the potential of intensive blood pressure control in preventing dementia among patients with hypertension. Dementia is defined by a decline in cognitive function that hampers daily activities, with Alzheimer’s disease being the most prevalent form. Mild cognitive impairment (MCI) represents a transitional state between normal age-related cognitive decline and dementia. Observational studies have associated high blood pressure with an increased risk of MCI and dementia, particularly since many Alzheimer’s patients exhibit vascular damage.

Research Gap and SPRINT Trial Overview

Despite the observations, previous studies have not conclusively established the impact of blood pressure management on dementia risk. To fill this research gap, the SPRINT Mind Investigators from the United States conducted the Systolic Blood Pressure Intervention Trial (SPRINT). This trial aimed to compare the outcomes of intensive blood pressure control against standard control in relation to dementia risk, with findings published in JAMA.

The trial included participants over the age of 50 from over a hundred sites in the United States and Puerto Rico, all having blood pressure readings between 130 and 180 mmHg and a high risk of cardiovascular disease. Individuals with existing dementia, diabetes, or a history of stroke were excluded from the study.

Trial Methodology

Participants were randomly assigned to either the intensive blood pressure control group, targeting a systolic pressure of less than 120 mmHg, or the standard control group, aiming for a target of less than 140 mmHg. Cognitive assessments were conducted at the start and during follow-ups to determine the incidence of probable dementia, MCI, and the combined occurrence of both conditions.

The SPRINT trial was halted after 3.3 years due to evident benefits from intensive blood pressure management in terms of cardiovascular health and mortality. Nonetheless, researchers continued to monitor dementia and MCI development for the full five-year duration originally planned.

Findings on Dementia and Cognitive Impairment

Out of the 9,361 subjects enrolled, 149 in the intensive treatment group were identified with probable dementia, compared to 176 in the standard group. This difference did not reach statistical significance. Conversely, the incidence of mild cognitive impairment was significantly lower in the intensive blood pressure control group compared to the standard group. While MCI is recognized as a strong risk factor for dementia, it was not the primary outcome of this trial, leaving the long-term implications of these findings unclear.

Conclusion and Future Directions

Although the study did not demonstrate a significant reduction in dementia risk through strict blood pressure control, it marks the first investigation of a modifiable risk factor in the prevention of dementia. Currently, there are no established treatments to prevent or slow the progression of dementia, which is the focus of ongoing research. This study lays the groundwork for future investigations aimed at identifying potential strategies for dementia prevention or progression mitigation.

Author Information

Written by Maggie Leung, PharmD

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References

Williamson, J. D., Pajewski, N. M., Auchus, A. P., Bryan, R. N., Chelune, G., Cheung, A. K., . . . Wright, C. B. (2019). Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia. JAMA, 321(6), 553. doi:10.1001/jama.2018.21442

Balintfy, J. (2019, January 28). Does intensive blood pressure control reduce dementia? Retrieved from https://www.eurekalert.org/pub_releases/2019-01/nioa-dib012419.php