Temporal evolution of cognitive changes in incident hypertension: prospective cohort study across the adult age span

Abstract

Midlife hypertension is a risk factor for dementia, but little is known about the cognitive trajectories of individuals with incident hypertension. This study follows the cognitive functioning in prevalent and incident hypertension for 12 years and in relation to age and treatment status. Cognitively intact adults aged 25 to 84 years (n=1805) were serially assessed at baseline, 6 years, and 12 years. Hypertension was defined by sphygmomanometry or antihypertensive medication use, and its association with cognitive decline was tested in random-effects models. At baseline, 638 (35.3%) participants had hypertension. They showed faster decline in memory (χ(2) test for homogeneity=35.75; df=2; P<0.001), executive functions (χ(2)=21.68; df=2; P<0.001), and information processing speed (χ(2)=81.96; df= 2; P<0.001) than baseline normotensive participants. At follow-up, 352 individuals (30.2%) developed incident hypertension. They showed faster decline in memory (χ(2)=7.88; df=2; P=0.019) and information processing speed (χ(2)= 18.06; df=2; P<0.001), especially from 6- to 12-year follow-up. Effects were most pronounced and widespread in midlife for both prevalent and incident hypertension and in those with untreated and uncontrolled hypertension. This study shows that incident hypertension predicts cognitive decline in middle-aged individuals, and those with poorly controlled blood pressure are most at risk. In newly diagnosed individuals, decline evolves gradually, possibly opening a window for early intervention.

Keywords: cognition; cohort studies; dementia; epidemiology; neuropsychology.