Education and Cognitive Change over 15 Years: The Atherosclerosis Risk in Communities Study

Abstract

OBJECTIVES To evaluate whether education level is associated with change in cognitive performance. DESIGN Prospective cohort study. SETTING The Atherosclerosis Risk in Communities (ARIC) Study, a community-based cohort. PARTICIPANTS Nine thousand two hundred sixty-eight ARIC participants who underwent cognitive evaluation at least twice over a 15-year period. MEASUREMENTS Education was evaluated as a predictor of change in word recall, the Digit Symbol Substitution Test (DSST), and word fluency. A random-effects linear regression model, and a time by educational level interaction was used. RESULTS Educational level was highly associated with cognitive performance. The effect on performance of a less than high school education (vs more than high school) was equivalent to the effect of as much as 22 years of cognitive aging, but educational level was not associated with change in cognitive performance in whites or blacks, with the exception of the DSST for whites, in whom those with lower levels of education had less decline in scores. CONCLUSION Educational level was not associated with change in cognitive performance, although the higher baseline cognitive performance of individuals with more education might explain lower rates of dementia in more-educated individuals, because more decline would have to take place between baseline higher performance and time at which dementia was diagnosed in more-educated individuals.

Association of Depression With Accelerated Cognitive Decline Among Patients With Type 2 Diabetes in the ACCORD-MIND Trial

“…Over 40 months of follow-up in the MIND sample, non-depressed patients had a mean decline in unadjusted DSST scores of 1.7 points (0.51 points annual decline), while depressed patients declined 2.7 points (0.81 points annual decline). This compares to an approximately 0.49 points annual decline in the Atherosclerosis Risk in Communities Study (ARIC) sample mean aged 56.7 at baseline 24 and approximately 0.87 points annual decline in the Health, Aging, and Body Composition Study (HABC) sample of persons mean age 74.2 years with prevalent diabetes. 25 These studies did not compare declines by depression groups.…”

Defining the Relationship Between Hypertension, Cognitive Decline, and Dementia: a Review

“…These findings have been further supported by longitudinal studies which show that high midlife BP is associated with increased cognitive decline over time [13–15]. Because confounding variables, such as education and socioeconomic status, are less likely to affect cognitive change (compared to baseline cognitive abilities) [16], studies which show an increased rate of cognitive decline over time among hypertensive adults provide especially strong evidence for the deleterious effects of high BP. As will be discussed below, several studies have also identified hypertension duration and the trajectory of BP levels over time as important determinants of cognitive function later in life [17,18].…”

Midlife Hypertension and 20-Year Cognitive Change

“…The utility of this approach is demonstrated by previous findings in the ARIC Study that educational level, although strongly associated with cognitive performance at any single visit, is not an important predictor of cognitive change . 38,39 …”