Cardiovascular risk factors and cognitive decline in middle-aged adults

TLDR

The study aimed to identify vascular risk factors for cognitive decline by serial neuropsychological testing in the Atherosclerosis Risk in Communities cohort of middle‑aged adults. Cognitive performance was measured in 10,963 participants (8,729 white, 2,234 black) aged 47–70 using delayed word recall, digit symbol subtest, and word fluency tests at two time points six years apart. Diabetes and hypertension were linked to greater cognitive decline over six years, while smoking, carotid thickness, and hyperlipidemia showed no association; these findings suggest early intervention on blood pressure and glucose control could reduce later cognitive impairment.

Abstract

<b><i> Objective:</i></b> To perform serial neuropsychological assessments to detect vascular risk factors for cognitive decline in the Atherosclerosis Risk in Communities cohort, a large biracial, multisite, longitudinal investigation of initially middle-aged individuals. <b><i>Methods:</i></b> The authors administered cognitive assessments to 10,963 individuals (8,729 white individuals and 2,234 black individuals) on two occasions separated by 6 years. Subjects ranged in age at the first assessment from 47 to 70 years. The cognitive assessments included the delayed word recall (DWR) test, a 10-word delayed free recall task in which the learning phase included sentence generation with the study words, the digit symbol subtest (DSS) of the Wechsler Adult Intelligence Scale–Revised and the first-letter word fluency (WF) test using letters F, A, and S. <b><i>Results:</i></b> In multivariate analyses (controlling for demographic factors), the presence of diabetes at baseline was associated with greater decline in scores on both the DSS and WF (<i>p</i> &lt; 0.05), and the presence of hypertension at baseline was associated with greater decline on the DSS alone (<i>p</i> &lt; 0.05). The association of diabetes with cognitive decline persisted when analysis was restricted to the 47- to 57-year-old subgroup. Smoking status, carotid intima–media wall thickness, and hyperlipidemia at baseline were not associated with change in cognitive test scores. <b><i>Conclusions:</i></b> Hypertension and diabetes mellitus were positively associated with cognitive decline over 6 years in this late middle-aged population. Interventions aimed at hypertension or diabetes that begin before age 60 might lessen the burden of cognitive impairment in later life.