Hajjar I, Quach L, Yang F et al.
Harvard Medical School, Boston, MA, USA.
Circulation 2011;123:858–65.
Editor’s note: This large study documents again that abnormally elevated blood pressure is bad for cognition as people grow older, particularly when it is associated with white matter damage visible on brain magnetic resonance imaging (MRI) scans. The authors followed 4700 participants (aged >65 years) over a period between 1992 and 2005, and found that the participants who had hypertension at baseline were more likely than those with normal blood pressure to have lower scores on the Digit Symbol Substitution Test, as well as slower gait speeds and more depressive symptoms (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.04–1.42; p=0.01). Of the participants who were not impaired in all of these measures at baseline, those with hypertension were more likely than those without it to develop all three impairments over the period of follow-up (HR 1.3, 95% CI 1.02–1.66; p=0.037).