High-normal blood pressure is associated with poor cognitive performance

Abstract

While the relation between systolic blood pressure (SBP) and vascular events is linear down to the high-normal range, the relation between SBP and cognition is less clear. We cross-sectionally assessed the relation between SBP and cognition in a cohort extending from mid- to late-life. From a total of 2200 community-dwelling individuals we recruited 377 aged 44 to 82 years (median: 64 years, 171 male) in the SEARCH-Health study (Systematic evaluation and alteration of risk factors for cognitive health). Participants were studied with a comprehensive neuropsychological test battery that provided, based on principal component analysis, 5 composite scores for cognition (learning and memory, attention and executive function, spatial skills, working memory, and verbal skills). Global cognition was calculated from the sum of the composite scores. SBP (corrected R(2)=0.007), education (corrected R(2)=0.203), age (corrected R(2)=0.102), and gender (corrected R(2)=0.011) explained one third of variance in global cognitive performance (P<0.001) on multivariate analyses. Moreover, the relation between SBP (based on 10 mm Hg-categories from <120 mm Hg to >170 mm Hg) and global cognitive performance was linear in this range of SBP-values, ie, even in the normotensive range (beta=-0.110, P<0.05). Subgroup analysis showed that the association of SBP and cognition was driven by results in midlife (<60 years) individuals (beta=-0.291, P<0.005). Thus, even in the normotensive range increasing systolic blood pressure is inversely related to cognition.