Diastolic Blood Pressure and Cognitive Function in Adults With Achieved Systolic Blood Pressure Below 130 mm Hg: Insights From the SPRINT-MIND Trial.

Abstract

Background: The potential J-shaped relationship whereby lower diastolic blood pressure (DBP) is associated with a higher risk of adverse cognitive outcomes has raised concerns regarding intensive systolic blood pressure (SBP) lowering. However, the current guidelines advocate a stricter SBP target of <130 mm Hg, with no clear consensus on a DBP target, especially with respect to brain health. The present study aimed to determine the relationship between treated DBP and cognitive function, as well as cerebral perfusion and structure, in adults who achieved an SBP <130 mm Hg.

Methods: This secondary analysis of SPRINT-MIND (Systolic Blood Pressure Intervention Trial Memory and Cognition in Decreased Hypertension) included hypertensive participants with achieved SBP <130 mm Hg, irrespective of their original assignment to the intensive or standard treatment arm. We evaluated cognitive outcomes (probable dementia and mild cognitive impairment) and changes in cerebral blood flow, white matter lesions, and total brain volume according to achieved DBP category (<60, 60-69, 70-79, and ≥80 mm Hg) and achieved DBP as a continuous variable. Cox regression models and linear mixed models were used in analyses.

Results: In total, 4424 participants (67.4±9.1 years; 2875 [65.0%] men) were included. In the crude model, low on-treatment DBP was significantly associated with increased risks of probable dementia and mild cognitive impairment. However, after correction for all potential covariates, the statistical significance of the association was lost (all P>0.05). Treated DBP was not associated with changes in white matter lesions or total brain volume; however, there was a significant inverse relationship between achieved DBP and cerebral blood flow changes (P for trend =0.029; difference in change, -1.94 mL/100 g per minute [95% CI, -3.50 to -0.39] per 5-mm Hg increase).

Conclusions: In patients achieving an SBP <130 mm Hg, treated DBP was not associated with dementia, mild cognitive impairment, or changes in white matter lesions and total brain volume. However, there was an increased risk of impaired cerebral perfusion in patients with elevated on-treatment DBP.